810-005, Rev. E
DSMS Telecommunications Link
Design Handbook
001
Handbook Introduction
Effective November 30, 2000
Document Owner: Approved by:
----------------------- -----------------------
R.W. Sniffin Date K.R. Kimball Date
Manager, DSMS Implementation
Engineering
Released by:
[Signature on file in TMOD Library]
----------------------------------
TMOD Document Release Date
Change Log
Rev Issue Date Affected Paragraphs Change Summary
Initial 1/15/2001 All All
Note to Readers
There are two sets of document histories in the 810-005 document, and these
histories are reflected in the header at the top of the page. First, the
entire document is periodically released as a revision when major changes
affect a majority of the modules. For example, this module is part of 810-005,
Revision E. Second, the individual modules also change, starting as an initial
issue that has no revision letter. When a module is changed, a change letter
is appended to the module number on the second line of the header and a
summary of the changes is entered in the module's change log.
This module supersedes module INT-10 in 810-005, Rev. D.
Contents
Paragraph Page
1 Introduction............................................................. 3
1.1 Purpose ............................................................... 3
1.2 Scope.................................................................. 3
1.3. Distribution.......................................................... 4
2 General Information ..................................................... 4
2.1 Constraints............................................................ 4
2.2 Types of Data.......................................................... 5
2.3 Proposed Capabilities ................................................. 5
2.4 Document Layout ....................................................... 5
2.5 Module Revision and Control............................................ 6
2.6 Abbreviations.......................................................... 6
2.7 Applicable Documents................................................... 6
2.7.1 DSMS External Documents.............................................. 6
2.7.2 DSMS Internal Documents ............................................. 7
1 Introduction
1.1 Purpose
This modular handbook has been approved by the Deep Space Mission Systems
(DSMS) Engineering Program Office and is published as a source of interface
design data for all flight projects using the Deep Space Network (DSN). It
provides information useful to flight projects contemplating the design of
hardware and software, with reasonable assurance that the resulting project
telecommunications interfaces will be compatible with the established or
planned DSN configurations.
1.2 Scope
The handbook consists of modules that present technical information applicable
to the current DSN configuration and preliminary information applicable to
future DSN configurations. These modules will be revised to reflect new
capabilities and distributed to all users as these capabilities become
approved by the DSMS Engineering Program Office.
This handbook is primarily concerned with performance parameters of equipment
that supports the forward and return telecommunications link interfaces
between spacecraft and the DSN. Other interfaces, such as ground data
interfaces and administrative interfaces, are covered in a companion handbook,
the Telecommunications and Mission Operations Directorate (TMOD) Document 810-
007, DSMS Mission Interface Design Handbook.
1.3. Distribution
This handbook is published as an electronic document. However, organizations
or individuals under contract to, or having received a request for proposal
from, the National Aeronautics and Space Administration (NASA) or one of its
centers, may receive loose-leaf bound printed copies upon request to the DSMS
Engineering Program Office or the editor of this document. Persons receiving
printed copies will normally be notified of revisions by electronic mail but
may also request delivery of printed revisions. Persons having no further use
for printed copies of the document are requested to return them to the editor
of this document. The purpose of this request is to minimize the possibility
of documents remaining in circulation if they are not being maintained.
Requests for mailing address changes should also be submitted to the editor of
this document.
2 General Information
2.1 Constraints
The disclosure of a capability by this handbook does not ensure that it can be
made available to all potential DSN users. Specific support commitments must
be negotiated between individual flight projects and the TMOD Plans and
Commitments Office. Details about this office, names for personnel to contact,
and their electronic addresses are available at the following website:
. Furthermore, this handbook does not
relieve projects of the responsibility for obtaining frequency spectrum
support for their equipment designs. This spectrum support is obtained through
the JPL Frequency Manager, who is resident in the Plans and Commitments
Program Office . In seeking viable solutions to telecommunications or data-
processing problems, flight projects are not necessarily constrained by the
effective design parameters contained in this handbook. However, flight
project requirements that could require DSN interface design beyond what is
specified by this handbook are subject to negotiation with the Plans and
Commitments Program Office. The term user appears throughout this handbook
whenever a mode of operation or parameter must be selected by a flight
project. It must be understood that it is only in rare cases that these
decisions can be made in real time. All DSN activities are planned well in
advance and conducted by highly skilled persons trained in handling
contingencies. Changes to planned operations must be made in accordance with
DSN procedures that are beyond the scope of this document.
2.2 Types of Data
It is the intent of this handbook to provide data verified by measurement and,
therefore, representing actual performance. Unless clearly marked to the
contrary, data in this handbook should be assumed to comply with this intent.
Sometimes it is necessary to include DSN design performance data that have not
been verified by measurement. These data will be clearly identified in the
associated text or by appropriate marking. As hardware and software are tested
and evaluated under operational conditions throughout the DSN, performance
parameters will be upgraded to represent actual performance and published in
the next revision of the appropriate module.
2.3 Proposed Capabilities
Whenever sufficient information is known about a capability being implemented
in the DSN and having adequate maturity to be considered for spacecraft
mission and equipment design, this information will be included in the
appropriate modules under the heading of Proposed Capabilities.
Telecommunications engineers are advised that anything discussed under this
heading cannot be committed to except by negotiation with the TMOD Plans and
Commitments Program Office.
2.4 Document Layout
The modules in this revision of 810-005 have been divided into major sections
that can be identified by their module numbers and the color of the tabs in
the printed version or the index to the on-line version. This module is part
of an introductory section that may be expanded in the future to include
tutorial or summary information. Modules in this section have yellow tabs and
numbers starting with 0. The next section, Space Link Interfaces, contains
modules that provide information to those concerned with antenna selection and
propagation effects. Modules in this section have blue tabs and numbers
starting with 1. The third section, Station Data Processing, contains modules
that provide capabilities and performance of equipment installed in the Signal
Processing Center (SPC) portion of each DSN location. This information will be
of interest both to telecommunications engineers and spacecraft mission
designers. Modules in this section have green tabs and numbers starting with
2. The fourth section in this revision, Ground Station Properties, contains
modules that provide information about the underlying technologies relating to
many of the Space Link Interfaces and Station Data Processing modules. These
modules have been grouped to consolidate this information in one place.
Modules in this section have brown tabs and numbers starting with 3.
2.5 Module Revision and Control
The modules contained in this handbook are approved for publication under the
authority of the cover page signatories. Revisions are indicated by a revision
letter following the module designator. A summary of the changes and additions
to the on-line version of 810-005 can be accessed on the home page of the
document, located at the website listed on the cover and title page of this
document. Currency of modules in printed copies can be verified against the
information in the Table of Contents supplied with each revision or by
comparison with the online version. Minor corrections or changes to printed
copies may be issued in the form of module change pages that will be
appropriately marked and recorded in a Change Log near the front of the
module. Persons requesting additions of modules to the handbook should direct
their request to the DSMS Engineering Program Office. Persons requesting
changes, corrections, or additions to existing modules should direct their
comments to either of the cover page signatories or to their functional titles
at the DSMS Engineering Program Office. All modules are subject to the review
and approval process of TMOD Standard Practice, DSMS Documentation Structure,
Standards, and Definitions; TMOD Document 810-001.
2.6 Abbreviations
Abbreviations are normally defined after their first textual usage and are
compiled in module 901, Handbook Glossary. It should be recognized, however,
that certain common abbreviations or acronyms used in this handbook may not
defined. External users may refer to any of several compilations of electronic
terms for omitted definitions. Users with access to the JPL Intranet can find
additional abbreviations in DSMS System Engineering Standard; DSMS
Abbreviations and Acronyms, TMOD Document 820-062.
2.7 Applicable Documents
The latest issues of the following documents are referenced by modules in this
handbook or are the source of requirements for this handbook or the
capabilities described herein.
2.7.1 DSMS External Documents
The following documents either are public documents or may be made available
to organizations or individuals under contract to, or having received a
request for a proposal from, NASA or one of its centers.
1. The Telecommunications and Mission Operations Progress Report, On-line
document
2. DSMS Standard Practice, DSMS Mission Interface Design Handbook; TMOD
Document 810-007
3. DSMS Requirements and Design, DSMS External Interface Specification; TMOD
Document 820-013
2.7.2 DSMS Internal Documents
The following DSMS internal documents are referenced by, or provide
requirements for, this handbook and may be found at the Product Data
Management System website .
1. TMOD Standard Practice, DSMS Documentation Structure, Standards, and
Definitions; TMOD Document 810-00l
2. DSMS System Engineering Standard, DSMS Abbreviations and Acronyms; TMOD
Document 820-062
3. DSMS Subsystem Requirements and Design; TMOD Document Series 83
810-005, Rev. E
DSMS Telecommunications Link
Design Handbook
101
70-m Subnet
Telecommunications Interfaces
Effective November 30, 2000
Document Owner: Approved by:
----------------------- -----------------------
S.D. Slobin Date A.J. Freiley Date
Antenna System Engineer Antenna Product Domain Service
System Development Engineer
Released by:
[Signature on file in TMOD Library]
----------------------------------
TMOD Document Release Date
Change Log
Rev Issue Date Affected Paragraphs Change Summary
Initial 1/15/2001 All All
Note to Readers
There are two sets of document histories in the 810-005 document, and these
histories are reflected in the header at the top of the page. First, the entire document is
periodically released as a revision when major changes affect a majority of the modules. For
example, this module is part of 810-005, Revision E. Second, the individual modules also
change, starting as an initial issue that has no revision letter. When a module is changed, a
change letter is appended to the module number on the second line of the header and a summary
of the changes is entered in the module's change log.
This module supersedes TCI-10 in 810-005, Rev. D.
Contents
Paragraph Page
1 Introduction........................................................................................... 4
1.1 Purpose.............................................................................................. 4
1.2 Scope ............................................................................................... 5
2 General Information ................................................................................... 5
2.1 Telecommunications Parameters........................................................................ 6
2.1.1 Antenna Gain Variation ............................................................................ 6
2.1.1.1 Frequency Effects ............................................................................... 6
2.1.1.2 Elevation Angle Effects ......................................................................... 6
2.1.1.3 Wind Loading .................................................................................... 7
2.1.2 System Noise Temperature Variation ................................................................ 7
2.1.3 Pointing Accuracy.................................................................................. 8
2.2 Recommended Minimum Operating Carrier Signal Levels.................................................. 8
3 Proposed Capabilities.................................................................................. 8
3.1 70-m X-Band Uplink Implementation ................................................................... 8
Appendix A, Equations for Modeling ..................................................................... 36
A.1 Equations for Gain Versus Elevation Angle .......................................................... 36
A.2 Equations for System Temperature Versus Elevation Angle............................................. 37
A.3 Equation for Gain Reduction Versus Pointing Error .................................................. 38
Illustrations
Figure Page
1. Functional Block Diagram of DSS 14 and DSS 43 Microwave and Transmitter Equipment.................... 26
2. Functional Block Diagram of DSS 63 Microwave and Transmitter Equipment .............................. 27
3. S-Band Receive Gain Versus Elevation Angle, All Stations ............................................ 28
4. Predicted X-Band Receive Gain Versus Elevation Angle, DSS 14 Antenna,
X-Only Configuration (S/X Dichroic Retracted) ....................................................... 28
5. Predicted X-Band Receive Gain Versus Elevation Angle, DSS 43 Antenna,
X-Only Configuration (S/X Dichroic Retracted) ....................................................... 29
6. X-Band Receive Gain Versus Elevation Angle, DSS 63 Antenna .......................................... 29
7. L-Band System Noise Temperature, All Stations ....................................................... 30
8. S-Band System Noise Temperature Versus Elevation Angle, DSS 14, LNA-1,
Non-diplexed ........................................................................................ 30
9. Eastern Horizon S-Band System Noise Temperature at 6 deg Elevation Angle ............................ 31
10. Western Horizon S-Band System Noise Temperature at 6 deg Elevation Angle ........................... 31
11. Predicted X-Band System Noise Temperature Versus Elevation Angle,
DSS 14, X-Only Configuration (S/X Dichroic Retracted)................................................ 32
12. Predicted X-Band System Noise Temperature Versus Elevation Angle,
DSS 43, X-Only Configuration (S/X Dichroic Retracted)................................................ 32
13. X-Band System Noise Temperature Versus Elevation Angle, DSS 63 ..................................... 33
14. L-Band and S-Band Pointing Loss Versus Pointing Error............................................... 33
15. X-Band Pointing Loss Versus Pointing Error ......................................................... 34
Tables
Table Page
1. S- and X-Band Transmit Characteristics................................................................ 9
2. L-, S-, and X-Band Receive Characteristics .......................................................... 14
3. Gain Reduction Due to Wind Loading, 70-m Antenna..................................................... 17
4. System Noise Temperature Contributions due to 25% Weather............................................ 18
5. DSS 14 Eastern Horizon S-Band Top (K) with SPD Cone ................................................. 19
6. DSS 14 Western Horizon S-Band Top (K) with SPD Cone.................................................. 20
7. DSS 43 Eastern Horizon S-Band Top (K) with Ultracone ................................................ 21
8. DSS 43 Western Horizon S-Band Top (K) with Ultracone................................................. 22
9. DSS 63 Eastern Horizon S-Band Top (K) with SPD Cone ................................................. 23
10. DSS 63 Western Horizon S-Band Top (K) with SPD Cone................................................. 24
11. Recommended Minimum Operating Carrier Signal Levels (dBm) .......................................... 25
A-1. Vacuum Component of Gain Parameters................................................................ 38
A-2. Zenith Atmosphere Attenuation Above Vacuum (AZEN).................................................. 39
A-3. Vacuum Component of System Noise Temperature Parameters ........................................... 39
1 Introduction
1.1 Purpose
This module provides the performance parameters for the Deep Space Network
(DSN) 70-meter antennas that are necessary to perform the nominal design of a
telecommunications link. It also summarizes the capabilities of these antennas for mission
planning purposes and for comparison with other ground station antennas.
1.2 Scope
The scope of this module is limited to providing those parameters that
characterize the RF performance of the 70-meter antennas. The parameters do not include
effects of weather, such as reduction of system gain and increase in system noise temperature,
that are common to all antenna types. These are discussed in module 105, Atmospheric and
Environmental Effects. This module also does not discuss mechanical restrictions on antenna
performance that are covered in module 302, Antenna Positioning.
2 General Information
The DSN 70-m Antenna Subnet contains three 70-meter diameter antennas. One
antenna (Deep Space Station [DSS] 14) is located at Goldstone, California; one (DSS 43) is near
Canberra, Australia; and one (DSS 63) is near Madrid, Spain. The precise station locations are
shown in Module 301, Coverage and Geometry. All antennas support L-, S-, and X-band
reception and S-band transmission. In addition, DSS 14 and DSS 43 have an X-band
transmission capability.
Figure 1 is a block diagram of the S-band and X-band microwave and transmitter
equipment at DSS 14 and DSS 43 that is common to the two stations. The diagram does not
show the S-band Ultracone that has been installed at DSS 43 in support of the Galileo S-band
mission. A block diagram of the S-band and X-band microwave and transmitter equipment at
DSS 63 is shown in Figure 2.
All three stations include the S-band, Polarized, Diplex feedcone (the SPD cone)
that contains the feed, the primary low-noise amplifier (LNA) and its support equipment, the
diplexer, and the required switches and other waveguide. The backup LNA and S-band
transmitters are located in an area beneath the feedcones. Two S-band transmitters are provided
for spacecraft communication: a 20-kW S-band transmitter for normal spacecraft communication
and a 400-kW transmitter for emergency commanding. The Goldstone site also has a radar
transmitter that operates near the normal receive frequency band. The feed employs an
orthomode junction that permits simultaneous right-circular polarization (RCP) and left-circular
polarization (LCP) to be used. The polarizer may be switched so that either polarization may be
directed to the non-diplexed path with the opposite polarization appearing on the diplexed path.
The non-diplexed path (orthomode upper arm) is used for listen-only reception or if the
spacecraft transmits and receives on opposite polarizations. If the spacecraft receives and
transmits simultaneously with the same polarization, the diplexed path must be used, and the
noise temperature is higher.
DSS 14 and DSS 43 employ the X-band Transmit-Receive feedcone (the XTR
cone). The XTR cone employs a unique feed design that includes a diplexing junction to inject
the transmitted signal directly into the feed. This eliminates the need for a waveguide diplexer
and a common path for the received and transmitted signals. As a result, much of the received
path can be cryogenically cooled with a significant reduction in operating system temperature.
The S/X dichroic plate can also be retracted when S-band is not required for a further
improvement in X-band performance. The XTR feed includes a fixed circular polarizer, an
orthomode junction, and two identical high-electron-mobility transistor (HEMT) low-noise
amplifiers. A separate polarizer is provided for the transmitter so that the transmitted signal can
be of either polarization
DSS 63 employs the older X-band receive only feedcone (the XRO cone). The
XRO cone includes a switchable polarizer, an orthomode junction, and two maser low-noise
amplifiers with their support equipment.
The S- and X-band feeds are provided with phase calibration couplers and comb
generators so the stations can be used for very-long baseline interferometry reception in addition
to spacecraft tracking.
2.1 Telecommunications Parameters
The significant parameters of the 70-meter antennas that influence
telecommunications link design are listed in Tables 1 and 2. Variations in these parameters that
are inherent in the design of the antennas are discussed below. Other factors that degrade link
performance are discussed in modules 105 (Atmospheric and Environmental Effects) and 106
(Solar Corona and Wind Effects).
2.1.1 Antenna Gain Variation
The antenna gains in Tables 1 and 2 do not include the effect of atmospheric
attenuation and should be regarded as vacuum gain at the specified reference point.
2.1.1.1 Frequency Effects
Antenna gains are specified at the indicated frequency (f0). For operation at higher
frequencies in the same band, the gain (dBi) must be increased by 20 log (f/f0). For operation at
lower frequencies in the same band, the gain must be reduced by 20 log (f/f0).
2.1.1.2 Elevation Angle Effects
Structural deformation causes a reduction in gain when the antenna operates at an
elevation angle other than the angle where the reflector panels were aligned. The net gain of the
antenna is also reduced by atmospheric attenuation, which is a function of elevation angle and
weather condition. These effects are illustrated in Figures 3 through 6, which show the estimated
gain versus elevation angle for the hypothetical vacuum condition (structural deformation only)
and with 0%, 50%, and 90% weather conditions, designated as CD (cumulative distribution) =
0.00, 0.50, and 0.90. A CD of 0.00 (0%) means the minimum weather effect (exceeded 100% of
the time). A CD of 90.0 (90%) means that effect which is exceeded only 10% of the time.
Qualitatively, a CD of 0.00 corresponds to the driest condition of the atmosphere; a CD of 0.50
corresponds to humid or very light clouds; and 0.90 corresponds to very cloudy, but with no rain.
A CD of 0.25 corresponds to average clear weather and is often used when comparing gains of
different antennas. Comprehensive S-band and X-band weather effects models (for weather
conditions up to 99% cumulative distribution) are provided in module 105 for detailed design
control use.
Figure 3 depicts the S-band (2295 MHz) net gains for all stations as a function of
elevation angle and weather condition, including the vacuum condition. Net gain means
vacuum-condition gain as reduced by atmosphere attenuation. DSS 43 gain is considered to be
identical, using both the SPD cone and the ultracone. The L-band gain curve shapes should be
considered identical to the S-band curve shapes, except that they are reduced in value by the
difference shown in Table 2. Figures 4 and 5 present the predicted X-band (8420 MHz) net
gains of the DSS 14 and DSS 43 antennas as a function of elevation angle and weather condition,
including the vacuum condition using the XTR feedcone with the S/X dichroic plate retracted.
The gains of the DSS 63 antenna, using the XRO feedcone, are shown for the same conditions in
Figure 6. The equations and parameters of these curves are given in Appendix A. The models
use a flat-Earth, horizontally stratified atmosphere approximation.
2.1.1.3 Wind Loading
The gain reductions at S- and X-band due to wind loading are listed in Table 3.
The tabular data are for structural deformation only and presume that the antenna is maintained
on-point by conical scan (CONSCAN, discussed in module 302) or an equivalent process. In
addition to structural deformation, wind introduces a pointing error that is related to the antenna
elevation angle, the angle between the antenna and the wind, and the wind speed. Cumulative
probability distributions of wind velocity at Goldstone are given in module 105.
2.1.2 System Noise Temperature Variation
The operating system temperature (Top) varies as a function of elevation angle due
to changes in the path length through the atmosphere and ground noise received by the sidelobe
pattern of the antenna. Figures 7 through 12 show the combined effects of these factors at L-, S-,
and X-bands in a hypothetical vacuum (no atmosphere) condition for selected antenna
configurations and with the three weather conditions described above. The equations and
parameters for these curves are provided in Appendix A of this module. The models use a flat-
Earth, horizontally stratified atmosphere approximation.
At S-band (2295 MHz), the clear-sky zenith noise temperatures of each antenna
are different; however, their elevation-related effects are considered to be similar. Figure 8
shows S-band noise-temperature curves for DSS 14, LNA-1, non-diplexed. Curves for other
antennas and configurations can be calculated by using the noise temperature values or
differences shown in Table 2. The L-band system temperature curve (Figure 7) is modeled from
the S-band curve so that at zenith the 25%-weather system temperature is 35 K. The X-band
(8420 MHz) system temperature curves for three stations are shown in Figures 11 through 13.
The figures for DSS 14 and DSS 43 using the XTR feedcone are estimates for X-band only
configuration (S/X dichroic plate retracted) based on pre-installation tests. The figure for DSS
63 is for S/X configuration using the XRO feedcone and is derived from measured data and the
weather model in module 105.
The system noise temperature values in Table 2 include a contribution due to 25%
weather that must be subtracted for comparison with antennas that are specified without
atmosphere (hypothetical vacuum). Table 4 provides adjustments to the 25% weather operating
system temperatures that were calculated using the weather models in module 105.
Tables 5 through 10 give S-band system noise temperatures to be expected during
average clear weather conditions at elevation angles near the horizon, corresponding to rise and
set azimuths of spacecraft with declinations of approximately -15 degrees to -25 degrees. These data were
gathered specifically to support the Galileo Mission during the 1995 through 1998 period.
Tables 5 and 6 are for rise and set azimuths at DSS 14 (Goldstone) using the Sband
SPD cone (the standard S-band receiving system). Tables 7 and 8 are for rise and set
azimuths at DSS 43 (Canberra) using the S-band ultracone (an additional, very-low-noise S-band
receiving system located on that antenna). Two-way operation (simultaneous transmit and
receive) or dual polarization (RCP and LCP) is not possible when the ultracone is being used for
reception. The standard SPD cone at DSS 43 is available for diplexed and non-diplexed
configuration with a somewhat higher noise temperature, as given in Table 2 and Appendix A,
Table A-3. Tables 9 and 10 give rise and set noise temperatures for DSS 63 (Madrid). The
elevation dependence of S-band noise temperature for all antennas is considered to be similar to
the DSS 14 performance depicted in Figure 8, subject to the low-elevation differences given in
Tables 5-10. Figures 9 and 10 show S-band system noise temperatures at a 6 degrees elevation angle
for all antennas at the eastern and western horizons for the Galileo range of rise and set azimuths.
2.1.3 Pointing Accuracy
Figure 14 shows the effects of pointing error on effective transmit and receive
gain of the antenna (pointing loss) for the S-band transmit and the L- and S-band receive
frequencies. The effects of pointing error at the X-band transmit and receive frequencies is
shown in Figure 15. These curves are Gaussian approximations based on theoretical antenna
beamwidths. Data have been normalized to eliminate elevation and wind-loading effects. The
equation used to generate the curves is provided in Appendix A.
2.2 Recommended Minimum Operating Carrier Signal Levels
Table 11 provides the recommended minimum operating carrier-signal levels for
selected values of receiver tracking-loop bandwidth (Bl). These levels provide a signal-to-noise
ratio of 10 dB in the carrier-tracking loop, based on the nominal zenith system temperatures
given in Table 2 and assuming 25% weather.
3 Proposed Capabilities
The following paragraphs discuss capabilities that have not yet been implemented
by the DSN but have adequate maturity to be considered for spacecraft mission and equipment
design. Telecommunications engineers are advised that any capabilities discussed in this section
cannot be committed to except by negotiation with the TMOD Plans and Commitments Program
Office.
3.1 70-m X-Band Uplink Implementation
DSS 63 will be equipped with the XTR feedcone and will have the same
capabilities as described for DSS 14 and DSS 43 and documented in Tables 1 and 2.
Table 1. S- and X-Band Transmit Characteristics
Parameter Value Remarks
ANTENNA
Gain (dBi) At gain set elevation angle, referenced to
feedhorn aperture for matched
polarization; no atmosphere included
S-Band (2115 MHz) 62.7 +/-0.2 All stations
X-Band (7145 MHz) 72.9 +/-0.2 DSS 14 and DSS 43
Transmitter Waveguide Loss
(dB)
S-Band All stations
0.2 +/-0.02 400-kW Transmitter output to feedhorn aperture
0.3 +/-0.02 20-kW Transmitter output to feedhorn aperture
X-Band 0.45 +/-0.02 20-kW Transmitter output to feedhorn
aperture, DSS 14 and DSS 43
Half-Power Beamwidth (deg) Angular width (2-sided) between halfpower
points at specified frequency
S-Band 0.128 +/-0.014
X-Band 0.0378 +/-0.003
Polarization RCP or LCP One polarization at a time, remotely
selected
Ellipticity, RCP or LCP (dB) Ellipticity is defined as the ratio of peak-to-trough
received voltages with a rotating,
linearly polarized source and a circularly
(elliptically) polarized receiving antenna.
Ellipticity (dB) = 20 log (V2/V1)
S-Band 2.2 (max) All stations
X-Band <=1.0 DSS 14 and DSS 43
Pointing Loss (dB)
Angular See module 302 Also, see Figures 14 and 15.
CONSCAN
S-Band
0.1 Recommended value
0.03 At S-band, using X-band CONSCAN
reference set for 0.1-dB loss
X-Band DSS 14 and DSS 43
0.1 Recommended value
EXCITER AND
TRANSMITTER
RF Power Output (dBm) Nominal output power, referenced to
transmitter port; settability is limited to 0.25
dB by measurement equipment precision
S-Band
20-kW Power Amplifier 73.0, +0.0, -1.0
400-kW Power Amplifier 86.0, +0.0, -1.0 See note at end of Table 1.
X-Band DSS 14 and DSS 43
20-kW Power Amplifier 73.0, +0.0, -1.0
Both S-band and X-band transmitters employ variable-beam klystron power amplifiers. The output
from this kind of amplifier varies across the bandwidth and may be as much as 1 dB below the
nominal rating, as indicated by the tolerance. Performance will also vary from tube to tube. Normal
procedure is to run the tubes saturated, but unsaturated operation is also possible. The point at
which saturation is achieved depends on drive power and beam voltage. The 20-kW tubes are
normally saturated for power levels greater than 60 dBm (1 kW) and the 400-kW tubes are saturated
above 83 dBm (200 kW). Minimum power out of the 20-kW tubes is about 53 dBm (200 W) and
about 73 dBm (20 kW) for the 400-kW tubes. Efficiency of the tubes drops off rapidly below nominal
rated output
EIRP At gain set elevation angle, referenced to
feedhorn aperture
S-Band
148.5, +0.0, -1.0 400-kW Transmitter
135.4, +0.0, -1.0 20-kW Transmitter
X-Band 145.4, +0.0, -1.0 DSS 14 and DSS 43
Frequency Range Covered
(MHz)
S-Band
1-dB Bandwidth 2110 to 2118
Coherent with Deep Space S-Band 2110.2 to 2117.7 240/221 turnaround ratio
D/L Allocation
Coherent with Deep Space X-Band 2110.2 to 2119.8 880/221 turnaround ratio
D/L Allocation
X-Band DSS 14 and DSS 43
1-dB Bandwidth 7145 to 7190
Coherent with Deep Space S-Band 7147.3 to 7177.3 240/749 turnaround ratio
D/L Allocation
Coherent with Deep Space X-Band 7149.6 to 7188.9 880/749 turnaround ratio
D/L Allocation
Tunability At S-band or X-band transmitter output
frequency
Phase Continuous Tuning Range 2.0 MHz
Maximum Tuning Rate +/-12.1 kHz/s
Frequency Error 0.012 Hz Average over 100 ms with respect to
frequency specified by predicts
Ramp Rate Error 0.001 Hz/s Average over 4.5 s with respect to rate
calculated from frequency predicts
S-Band Stability At transmitter output frequency
Output Power Stability (dB) 12-h period
Saturated Drive +/-0.25 20-kW Transmitter
Saturated Drive +/-0.5 400-kW Transmitter
Unsaturated Drive +/-1.0 20-kW and 400-kW transmitters
Frequency ((delta f)/f), 1000-s 5 x 10^-15 Allan deviation
Averaging
Phase Stability (dBc) In 1-Hz bandwidth
1-10 Hz Offset -60 Below carrier
10 Hz-1 kHz Offset -70 Below carrier
Group Delay Stability (ns) <=3.3 Ranging modulation signal path over
12-h period (see module 203)
Spurious Output
2nd Harmonic (dB) -85 Below Carrier
3rd Harmonic (dB) -85 Below Carrier
4th Harmonic (dBm) -140 dBm 20-kW Transmitter
TBD 400-kW Transmitter
X-Band Stability DSS 14 and DSS 43 at transmitter output
frequency
Output Power Stability (dB) 12-h period
Saturated Drive +/-0.25
Unsaturated Drive +/-1.0
Frequency ((delta f)/f), 1000-s 2.3 x 10^15 Allan deviation
Averaging
X-Band Stability (Continued) At transmitter output frequency
Phase Stability (dBc) In 1-Hz bandwidth
1-10 Hz Offset -50 Below carrier
10 Hz-1 kHz Offset -60 Below carrier
Group Delay Stability (ns) <=1.0 Ranging modulation signal path over
12 h period (see module 203)
Spurious Output
2nd Harmonic (dB) -75 Below carrier
3rd, 4th & 5th Harmonics -60 Below carrier
Note: 400-kW power amplifier cannot be used below 10 degree elevation at all stations and between
300 degree and 360 degree azimuth at DSS 63.
Table 2. L-, S-, and X-Band Receive Characteristics
ANTENNA
Gain (dBi) At gain set elevation angle for matched
polarization, no atmosphere included Note:
Favorable (+) and adverse (-) tolerances
have a triangular PDF. See Figures 3-6
for elevation dependency.
L-Band (1668 MHz) 60.17 +/-0.3 Referenced to LNA-1 or LNA-2 input
terminal (includes feedline loss)
S-Band (2295 MHz), All 63.34 +/-0.10 Referenced to LNA-1 input terminal
Stations (includes feedline loss)
63.28 +/-0.10 Referenced to LNA-2 input terminal
(includes feedline loss)
X-Band (8420 MHz), Referenced to LNA-1 or LNA-2 input
S/X Configuration terminal (includes feedline loss). S/X
dichroic is in place.
DSS 14 and DSS 43 74.1 +/-0.10 XTR Feedcone
DSS 63 74.28 +/-0.10 XRO Feedcone
X-Band (8420 MHz), 74.3 +/-0.10 DSS 14 and DSS 43, referenced to LNA-1
X-Only Configuration or LNA-2 input terminal (includes feedline
loss). S/X dichroic is retracted.
Half-Power Beamwidth Angular width (2-sided) between halfpower
(deg.) points at specified frequency
L- Band (1668 MHz) 0.162 +/-0.010
S- Band (2295 MHz) 0.118 +/-0.02
X-Band (8420 MHz) 0.0320 +/-0.003
Polarization
L-Band, All Stations LCP RCP available by changing mechanical
configuration of feed
S-Band, All Stations RCP and LCP Both polarizations available
simultaneously. Choice of diplexed or nondiplexed
path is remotely selectable.
X-Band
DSS 14 and DSS 43 RCP and LCP Both polarizations available
simultaneously.
DSS 63 RCP and LCP Both polarizations available
simultaneously. Choice of diplexed or nondiplexed
path is remotely selectable.
Ellipticity (dB) See definition in Table 1.
L-Band 2.0 (max)
S-Band 0.6 (max)
X-Band 0.8 (max)
Pointing Loss (dB, 3 sigma)
Angular See module 302 Also, see Figures 14 and 15.
CONSCAN
S-Band 0.03 At S-band using X-band CONSCAN
reference set for 0.1 dB loss at X-band
0.1 Recommended value when using S-band
CONSCAN reference
X-Band 0.1 Recommended value when using X-band
CONSCAN reference
LOW NOISE AMPLIFIERS Only two tracking receiver channels are
AND RECEIVERS available that may be operated as two
receivers with any pair or combination of
L-, S-, and X-band frequencies and
polarizations, for example, one S and one
X or X-RCP and X-LCP. Both receivers
also may be operated in the same band
and polarization.
Frequency Ranges Covered (MHz)) 1 dB bandwidth
L-Band 1628 to 1708
S-Band 2270 to 2300
X-Band 8400-8500
Recommended Maximum -90.0 At LNA input terminal
Signal Power (dBm)
Recommended Minimum See Table 11
Signal Power (dBm)
System Noise Temperature (K) For average clear weather (25% weather
condition) near zenith (see Table 4 for
adjustments to remove atmospheric
contribution); favorable (-) and adverse (+)
tolerances have a triangular PDF
L-Band (1628-1708 MHz) 21 +/-2 With respect to LNA 1 or 2 input terminal
(see Figure 7 for elevation dependency)
S-Band (2270-2300 MHz) See Figure 8 for representative elevation dependency
DSS 14 15.2, +1.3, -0.7 SPD cone, with respect to LNA-1 input
DSS 43 15.6, +1.4, -1.1 terminal, non-diplexed path
DSS 63 16.9, +1.7, -1.1
DSS 43 11.7, +1.0, -0.0 Ultracone with respect to LNA input
terminal
DSS 14 19.5, +1.3, -0.7 SPD cone, with respect to LNA-1 input
DSS 43 19.9, +1.4, -1.1 terminal, diplexed path
DSS 63 21.2, +1.7, -1.1
Adjustment for LNA-2 (All DSS) 5 +/-1 Add to diplexed or non-diplexed values
shown above to obtain performance with
LNA-2; tolerances to be RSS'd with
tolerances shown above
X-Band (8400-8500 MHz), Referenced to LNA-1 or LNA-2 input
S/X Configuration
terminal; S/X dichroic in place
DSS 14 17.4 +/-0.3 XTR Feedcone
DSS 43 17.8 +/-0.3 XTR Feedcone
DSS 63 21.0 +/-2 XRO Feedcone (see Figure 13 for
elevation dependency)
X-Band (8420 MHz), DSS 14 and DSS 43, referenced to LNA-1
X-Only Configuration or LNA-2 input terminal; S/X dichroic
retracted (see Figures 11 and 12 for
elevation dependency)
DSS 14 16.5 +/-0.3 XTR Feedcone
DSS 43 16.9 +/-0.3 XTR Feedcone
DSS 63 N/A XRO dichroic not retractable
Carrier Tracking Loop Noise 0.25 - 200 Effective one-sided, noise-equivalent
B/W (Hz) carrier loop bandwidth (BL)
Table 3. Gain Reduction Due to Wind Loading, 70-m Antenna
Wind Speed Gain Reduction (dB)*
km/h mph S-band X-band
32 20 Negligible 0.1
48 30 Negligible 0.3
72 45 0.15 1.5
* Assumes antenna is maintained on-point using CONSCAN or an equivalent.
L-band gain reduction is negligible for wind speeds up to 72 km/h (45 mph).
Worst case with antenna in most adverse orientation for wind.
Table 4. System Noise Temperature Contributions due to 25% Weather
Location Noise Temperature Contribution (K)*
L-band and S-band X-band
Goldstone (DSS 14) 1.929 2.292
Canberra (DSS 43) 2.109 2.654
Madrid (DSS 63) 2.031 2.545
* From Table 1 in module 105.
Table 5. DSS 14 Eastern Horizon S-Band Top (K) with SPD Cone
ELEV, AZIMUTH, deg
deg 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130
20.0 21.0 21.1 21.0 21.0 21.0 21.1 21.0 21.0 21.0 21.1 21.1 21.2 21.1 21.1 21.1 21.1 21.1 21.1 21.1 21.1 21.1
19.0 21.5 21.5 21.5 21.5 21.5 21.5 21.6 21.7 21.7 21.7 21.6 21.6 21.7 21.7 21.7 21.8 21.8 21.7 21.6 21.6 21.6
18.0 22.1 22.0 22.0 22.0 22.0 21.9 21.9 22.0 22.0 22.0 22.1 22.0 22.0 22.0 22.1 22.1 22.0 22.0 22.0 21.9 22.0
17.0 22.3 22.2 22.2 22.2 22.1 22.2 22.2 22.3 22.2 22.2 22.2 22.2 22.2 22.2 22.2 22.2 22.3 22.2 22.2 22.3 22.3
16.0 22.7 22.7 22.7 22.6 22.7 22.6 22.6 22.6 22.7 22.7 22.6 22.7 22.7 22.7 22.6 22.7 22.7 22.7 22.7 22.9 23.0
15.0 23.2 23.2 23.2 23.2 23.2 23.2 23.3 23.3 23.2 23.3 23.4 23.5 23.5 23.5 23.5 23.5 23.6 23.6 23.6 23.6 23.7
14.0 23.7 23.7 23.7 23.8 23.8 23.8 23.9 23.9 23.9 24.0 24.1 24.1 24.0 24.0 24.0 24.0 24.1 24.3 24.3 24.2 24.2
13.0 24.6 24.5 24.5 24.6 24.6 24.5 24.5 24.6 24.6 24.6 24.6 24.7 24.7 24.7 24.8 24.8 24.7 24.8 24.8 24.9 24.9
12.0 25.2 25.2 25.2 25.2 25.2 25.2 25.3 25.3 25.3 25.4 25.4 25.3 25.4 25.4 25.3 25.3 25.4 25.4 25.4 25.5 25.5
11.0 26.0 26.1 26.1 26.1 26.0 26.1 26.1 26.1 26.1 26.1 26.2 26.2 26.2 26.2 26.2 26.2 26.3 26.3 26.3 26.4 26.5
10.0 27.1 27.2 27.2 27.1 27.2 27.1 27.2 27.2 27.1 27.2 27.2 27.3 27.3 27.3 27.4 27.3 27.3 27.4 27.4 27.5 27.4
9.5 27.4 27.5 27.5 27.6 27.5 27.6 27.6 27.6 27.6 27.6 27.6 27.7 27.8 27.6 27.7 27.7 27.8 27.9 28.0 27.9 28.0
9.0 27.9 27.8 28.2 28.2 27.8 27.8 27.8 27.8 27.8 27.9 27.9 28.0 28.0 28.0 28.0 28.1 28.1 28.5 28.5 28.2 28.2
8.5 29.2 29.2 29.1 29.1 29.2 29.1 29.0 29.0 29.1 29.1 29.1 29.1 29.2 29.3 29.5 29.5 29.4 29.3 29.4 29.5 29.5
8.0 29.6 29.6 29.7 29.7 29.9 29.9 29.8 29.7 29.8 29.8 29.8 30.0 30.0 29.9 29.9 29.9 29.9 30.0 30.0 30.1 30.1
7.5 30.4 30.3 30.3 30.4 30.4 30.4 30.5 30.4 30.4 30.5 30.4 30.5 30.8 30.6 30.6 30.7 30.7 30.7 30.8 30.8 30.9
7.0 31.1 31.2 31.2 31.2 31.2 31.4 31.4 31.2 31.3 31.3 31.3 31.3 31.3 31.4 31.4 31.4 31.5 31.5 31.5 31.6 31.7
6.5 32.1 32.2 32.5 32.3 32.3 32.6 32.4 32.4 32.4 32.5 32.5 32.6 32.5 32.5 32.5 32.6 32.7 32.6 32.7 32.8 32.8
6.0 32.3 32.8 33.0 33.0 33.0 33.0 33.1 33.2 33.2 33.2 33.3 33.3 33.3 33.3 33.3 33.4 33.5 33.6 33.6 33.6 33.8
AZIMUTH, deg
130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150
20.0 21.1 21.1 21.1 21.1 21.1 21.2 21.2 21.7 21.6 21.1 21.2 21.2 21.2 21.2 21.1 21.1 21.2 21.2 21.2 21.2 21.2
19.0 21.6 21.6 21.6 21.6 21.6 21.6 21.5 21.7 22.1 21.8 21.6 21.8 22.0 21.6 21.6 22.1 21.9 21.6 21.6 21.6 21.6
18.0 22.0 22.0 21.9 21.9 21.9 22.0 22.0 21.9 22.0 22.1 22.1 22.1 22.5 22.6 22.1 22.2 22.8 22.5 22.1 22.3 22.8
17.0 22.3 22.4 22.5 22.6 22.5 22.5 22.5 22.4 22.5 22.5 22.6 22.6 22.6 22.6 22.5 22.5 22.5 22.6 22.5 22.6 22.7
16.0 23.0 22.8 22.8 22.9 22.9 22.9 23.0 23.0 23.1 23.1 23.1 23.2 23.3 23.2 23.1 23.3 23.3 23.1 23.1 23.2 23.2
15.0 23.7 23.6 23.6 23.7 23.6 23.6 23.6 23.7 23.7 23.7 23.8 23.8 23.8 23.8 23.8 23.7 23.7 23.8 23.8 23.7 23.7
14.0 24.2 24.2 24.2 24.2 24.5 24.9 24.6 24.5 24.5 24.5 24.5 24.4 24.4 24.5 24.5 24.5 24.5 24.7 25.0 24.6 24.6
13.0 24.9 24.9 25.0 25.0 25.1 25.2 25.0 24.8 25.0 25.1 25.2 25.2 25.3 25.3 25.3 25.3 25.3 25.5 25.5 25.5 25.5
12.0 25.5 25.5 25.5 25.6 25.6 25.6 25.6 25.6 25.7 25.7 25.7 25.8 25.8 25.9 25.9 25.9 25.9 26.0 26.0 26.0 26.1
11.0 26.5 26.5 26.5 26.9 27.5 26.8 26.8 27.3 26.8 26.6 26.6 26.7 26.6 26.7 26.7 26.7 26.7 26.8 26.9 26.9 26.9
10.0 27.4 27.5 27.5 27.7 27.7 27.6 27.7 27.7 27.7 27.8 27.8 27.9 27.8 27.8 27.7 27.9 27.9 27.9 27.9 28.0 28.1
9.5 28.0 28.0 28.1 28.1 28.2 28.1 28.1 28.1 28.1 28.2 28.2 28.3 28.3 28.3 28.4 28.4 28.4 28.5 28.4 28.4 28.4
9.0 28.2 28.3 28.3 28.4 28.4 28.4 28.5 28.5 28.6 28.6 28.5 28.6 28.7 28.8 28.7 28.8 28.8 28.9 28.9 28.9 28.9
8.5 29.5 29.6 29.7 29.6 29.7 29.9 29.9 29.9 30.0 29.6 29.9 30.1 29.8 29.8 30.0 30.0 29.9 29.9 30.0 30.0 30.0
8.0 30.1 30.1 30.2 30.2 30.3 30.5 30.4 30.3 30.4 30.5 30.4 30.5 30.4 30.3 30.5 30.6 30.6 30.6 30.6 30.7 30.8
7.5 30.9 30.9 30.9 31.1 31.2 31.2 31.2 31.2 31.3 31.4 31.5 31.4 31.4 31.4 31.5 31.5 31.5 31.5 31.6 31.7 31.8
7.0 31.7 31.8 31.9 31.8 32.0 32.1 32.1 32.2 32.1 32.0 32.1 32.2 32.2 32.2 32.2 32.2 32.3 32.4 32.5 32.8 32.9
6.5 32.8 32.9 32.9 33.0 33.1 33.2 33.2 33.2 33.2 33.3 33.6 33.5 33.4 33.4 33.4 33.5 33.6 33.7 33.9 34.1 34.2
6.0 33.8 33.8 33.8 34.0 34.0 34.0 34.1 34.1 34.1 34.3 34.3 34.4 34.4 34.5 34.6 34.6 34.7 34.8 35.0 35.2 35.4
Table 6. DSS 14 Western Horizon S-Band Top (K) with SPD Cone
ELEV, AZIMUTH, deg
deg 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230
9.0 29.7 30.0 31.0 32.0 31.5 30.6 30.0 29.6 29.3 29.3 29.2 29.1 29.0 29.0 28.8 29.0 29.0 29.1 29.0 29.0 29.0
8.5 31.0 31.3 32.3 32.3 31.2 30.6 30.3 30.0 29.9 29.7 29.7 29.7 29.6 29.6 29.5 29.5 29.5 29.5 29.5 29.5 29.5
8.0 27.2 31.5 31.9 33.1 33.8 32.4 31.3 31.1 31.0 30.7 30.6 30.5 30.5 30.8 30.4 30.3 30.4 30.7 30.5 30.4 30.5
7.5 34.7 34.9 34.9 34.9 34.5 33.3 32.3 32.0 31.7 31.4 31.3 31.2 31.2 31.2 31.2 31.2 31.1 31.0 30.9 31.0 31.1
7.0 34.3 34.3 34.3 34.2 34.2 34.2 33.8 33.0 32.5 32.2 32.1 31.7 31.9 31.9 31.9 31.8 31.8 31.8 31.7 31.7 31.8
6.5 34.4 34.3 34.2 34.3 34.2 33.8 33.4 33.0 32.9 33.0 32.8 32.8 32.8 32.8 33.0 32.8 32.8 32.7 32.7 32.7 32.7
6.0 34.6 34.1 34.7 34.8 34.8 34.7 34.4 34.0 33.8 33.7 33.7 33.7 33.7 33.7 33.6 33.6 33.6 33.5 33.6 33.5 33.6
AZIMUTH, deg
230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250
9.0 29.0 28.9 28.9 28.9 29.1 29.1 28.9 29.1 29.4 28.9 28.8 28.8 28.8 28.7 28.8 28.8 28.7 28.7 28.8 28.9 29.0
8.5 29.5 29.4 29.4 29.4 29.5 29.7 29.5 29.5 29.4 29.3 29.4 29.4 29.4 29.4 29.4 29.4 29.4 29.5 29.5 29.5 29.5
8.0 30.5 30.3 30.2 30.2 30.1 30.2 30.2 29.9 30.0 30.1 30.2 30.2 30.2 30.1 30.1 30.1 30.0 30.1 30.2 30.2 30.3
7.5 31.1 31.0 31.0 31.0 30.9 30.9 30.9 31.0 31.0 30.9 30.6 30.9 31.1 31.0 31.0 31.1 30.9 30.9 30.9 30.7 30.5
7.0 31.8 31.8 31.7 31.7 31.8 31.8 31.7 31.7 31.7 31.7 31.7 31.7 31.6 31.6 31.6 31.4 31.6 31.7 31.7 31.6 31.7
6.5 32.7 32.6 32.6 32.6 32.6 32.6 32.6 32.6 32.6 32.6 32.6 32.5 32.5 32.6 32.6 32.5 32.5 32.5 32.6 32.5 32.5
6.0 33.6 33.7 33.6 33.7 33.9 33.9 33.8 33.8 33.9 33.8 33.8 33.8 33.8 33.7 33.7 33.7 33.7 33.7 33.8 33.8 33.8
Table 7. DSS 43 Eastern Horizon S-Band Top (K) with Ultracone
ELEV, AZIMUTH, deg
deg 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110
20.0 19.0 18.7 18.2 18.9 18.4 18.7 19.0 18.8 18.4 18.7 18.8 18.5 18.2 18.9 18.6 18.7 18.3 19.0 18.3 18.1 18.7
19.0 19.4 19.5 19.3 19.2 19.5 20.1 19.6 19.4 19.3 19.3 18.9 18.7 19.2 19.4 18.8 19.4 19.0 19.0 18.9 19.1 18.8
18.0 20.3 20.0 20.2 19.6 19.7 19.9 20.1 20.2 20.1 19.9 20.2 19.6 20.2 20.1 19.9 19.8 19.6 19.5 20.0 19.6 19.4
17.0 21.1 21.2 20.4 20.6 20.9 20.4 21.2 20.8 21.2 21.1 20.7 20.9 20.8 20.4 20.4 20.9 20.9 20.3 20.2 20.3 20.7
16.0 21.5 21.5 21.1 21.7 21.3 21.5 21.4 21.6 21.4 21.1 21.6 21.3 21.6 21.3 21.4 21.5 21.5 21.2 21.2 20.7 21.0
15.0 22.8 22.7 22.0 22.4 22.2 22.3 22.0 22.7 22.1 22.7 22.3 22.2 22.4 22.3 21.6 22.1 22.3 22.3 22.0 21.8 21.8
14.0 23.3 23.6 23.2 23.5 23.5 23.0 23.3 23.1 23.1 23.2 23.2 23.5 23.3 23.3 22.8 22.9 23.0 23.1 22.4 22.8 22.4
13.0 24.3 23.7 24.0 24.3 23.8 24.6 24.1 23.7 24.0 24.3 23.7 23.9 23.9 24.1 23.8 23.8 23.7 23.8 24.0 23.5 23.6
12.0 25.1 25.3 25.2 25.7 25.2 25.5 25.4 25.4 25.2 25.6 25.1 25.3 25.0 25.0 24.9 25.0 25.1 24.9 24.4 24.8 24.6
11.0 26.5 26.9 26.4 26.0 26.1 26.7 26.3 26.9 27.5 26.8 27.1 27.5 26.9 26.8 27.0 26.0 26.0 26.1 26.0 25.9 25.8
10.0 33.6 32.8 30.6 29.7 29.4 29.4 30.1 33.3 39.9 51.4 58.3 59.1 56.1 48.6 37.1 30.7 28.7 27.8 28.0 27.3 27.2
9.5 50.5 50.1 46.9 41.7 38.5 39.2 45.0 53.9 67.5 82.2 94.3 98.1 94.0 82.4 67.3 53.3 40.3 31.7 29.9 29.0 27.7
9.0 77.0 76.1 71.6 66.6 65.0 69.7 80.5 96.0 114 131 141 142 133 116 96.4 77.9 60.4 45.8 38.6 34.1 31.3
8.5 111 112 111 107 104 104 112 125 143 161 177 187 184 173 155 134 111 90.9 75.1 64.4 54.6
8.0 151 150 148 145 146 151 161 177 195 211 222 223 215 201 182 160 141 124 109 96.9 82.2
7.5 190 191 191 188 185 187 195 207 222 234 240 240 238 236 227 211 195 178 165 153 134
7.0 219 220 220 218 216 220 227 236 240 242 242 241 240 240 238 232 222 212 203 190 171
6.5 235 236 237 237 236 236 239 240 243 244 244 243 242 241 241 242 241 238 236 230 220
6.0 239 240 239 239 240 240 241 242 243 243 243 243 242 241 242 242 242 241 241 239 233
AZIMUTH, deg
110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130
20.0 18.7 18.3 18.3 17.7 18.1 17.4 17.9 17.7 18.1 17.6 18.0 17.6 17.4 17.5 17.5 18.0 17.9 17.9 17.2 17.5 17.7
19.0 18.8 18.7 18.9 18.9 19.0 18.3 18.8 18.4 18.5 18.7 18.4 17.8 18.3 17.9 18.6 18.0 18.1 17.9 18.0 18.2 17.8
18.0 19.4 19.8 19.5 19.7 19.2 19.5 19.0 18.8 19.2 18.8 18.9 18.9 18.8 18.9 18.9 18.7 18.5 18.9 18.5 18.7 18.9
17.0 20.7 20.1 20.3 19.9 20.3 19.6 20.5 19.6 19.6 19.6 19.8 19.8 19.5 19.5 19.6 19.5 19.4 19.3 19.5 19.0 18.7
16.0 21.0 20.8 21.3 20.9 20.8 20.9 20.7 20.1 20.4 20.8 20.3 19.8 20.4 19.8 20.2 19.8 19.9 20.1 19.7 20.0 20.9
15.0 21.8 21.6 21.6 21.5 21.5 21.5 21.3 21.5 21.3 21.0 21.3 21.3 20.9 20.9 21.3 20.9 20.9 20.6 20.8 20.7 20.3
14.0 22.4 22.4 22.4 22.7 22.4 22.4 22.2 22.2 22.3 22.1 22.1 21.6 21.9 21.7 21.8 21.7 21.9 21.7 21.1 21.3 21.1
13.0 23.6 24.0 23.2 23.3 23.3 23.2 23.1 22.9 23.0 23.0 23.0 23.7 22.7 22.5 23.2 22.4 22.3 22.2 22.6 22.8 22.1
12.0 24.6 24.3 23.8 24.3 24.3 24.2 24.1 23.9 24.2 23.4 23.8 23.3 23.7 24.0 23.8 23.8 23.5 23.6 23.5 23.3 23.3
11.0 25.8 25.8 25.5 25.5 25.3 24.9 25.1 25.2 25.3 24.6 25.0 24.9 24.6 25.3 24.9 25.2 24.6 24.8 24.3 24.8 25.1
10.0 27.2 27.3 27.1 26.3 26.5 26.4 26.2 26.8 26.1 26.1 26.0 26.3 26.2 26.4 26.3 27.3 28.0 27.3 26.4 26.2 26.2
9.5 27.7 28.5 28.4 27.1 27.8 27.2 27.0 27.0 26.7 26.6 27.0 26.4 26.7 27.2 26.6 26.9 26.5 26.9 26.8 26.5 26.5
9.0 31.3 29.7 28.8 28.8 28.6 28.2 28.2 27.9 28.0 27.9 27.7 27.2 27.5 27.5 27.4 27.5 27.2 27.5 27.5 27.5 26.7
8.5 54.6 41.6 33.6 30.0 29.7 29.0 28.8 29.1 29.2 28.7 28.5 28.5 28.4 28.7 28.6 28.4 28.9 28.5 28.9 28.4 28.2
8.0 82.2 63.6 46.3 36.1 31.6 30.5 29.8 29.5 30.0 29.7 29.5 29.3 29.5 29.6 29.6 29.4 30.4 30.0 30.4 29.6 29.9
7.5 134 113 89.0 68.0 50.8 38.0 33.1 31.4 31.1 31.5 31.4 30.8 31.3 31.5 31.5 31.4 31.4 31.3 31.8 31.4 31.5
7.0 171 147 122 96.9 74.1 52.7 37.1 34.0 33.2 33.8 33.5 33.3 34.1 33.8 33.9 34.3 34.0 33.4 33.8 33.6 32.7
6.5 220 200 178 153 126 99.5 72.0 48.4 38.2 36.2 36.9 37.4 37.6 39.6 41.2 42.5 41.4 38.5 37.2 36.0 36.7
6.0 233 219 199 175 148 116 85.7 61.1 46.9 42.7 42.8 46.3 52.5 60.2 64.6 63.4 56.7 48.6 43.0 40.0 39.4
Table 8. DSS 43 Western Horizon S-Band Top (K) with Ultracone
ELEV, AZIMUTH, deg
deg 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250
20.0 17.4 17.3 17.4 17.5 17.3 17.6 17.4 17.5 17.7 17.5 17.5 17.5 17.4 17.6 17.7 17.4 17.6 17.6 17.5 17.6 17.5
19.0 18.0 18.0 18.2 18.1 18.2 18.2 18.1 18.2 18.1 18.3 18.3 18.2 18.3 18.5 18.3 18.2 18.1 18.2 18.3 18.3 18.2
18.0 18.7 18.6 18.7 18.7 18.8 19.0 18.8 18.7 18.9 19.0 19.0 18.9 18.9 19.0 18.8 18.9 18.9 18.8 18.9 18.9 18.7
17.0 19.4 19.3 19.5 19.4 19.4 19.4 19.4 19.6 19.5 19.4 19.6 19.5 19.6 19.4 19.5 19.4 19.4 19.5 19.3 19.5 19.5
16.0 20.0 20.1 20.0 20.2 20.4 20.2 20.2 20.3 20.3 20.2 20.3 20.3 20.2 20.1 20.2 20.2 20.4 20.1 20.2 20.1 20.3
15.0 20.9 20.9 21.0 20.9 21.0 21.0 21.0 21.0 21.1 21.1 21.0 21.1 21.1 21.1 21.0 21.0 21.0 20.9 21.1 21.2 20.9
14.0 21.9 21.7 21.6 21.6 21.6 21.7 21.9 21.8 21.9 21.8 21.9 21.9 22.0 21.9 21.9 21.9 21.9 21.8 21.8 21.7 21.7
13.0 22.5 22.5 22.7 22.6 22.6 22.6 22.6 22.7 22.6 22.7 22.7 22.8 22.8 22.6 22.8 22.7 22.7 22.7 22.8 22.7 22.5
12.0 23.5 23.4 23.4 23.5 23.5 23.6 23.7 23.6 23.7 23.6 23.9 23.7 23.8 23.9 23.8 23.9 23.8 23.7 23.7 23.7 23.7
11.0 24.9 25.0 25.1 25.2 25.1 25.2 25.3 25.4 25.3 25.4 25.2 25.3 25.4 25.4 25.5 25.5 25.4 25.3 25.3 25.2 25.0
10.5 25.1 25.2 25.1 25.4 25.4 25.7 25.6 26.1 26.8 26.8 26.4 26.0 26.5 27.1 26.5 26.7 27.5 27.3 26.0 25.6 25.7
10.0 25.9 26.0 26.6 27.4 27.4 27.4 28.8 31.4 32.0 31.4 29.7 29.5 32.1 31.2 29.8 32.8 32.7 29.0 27.4 27.1 27.1
9.5 27.7 28.0 28.0 30.3 32.8 32.6 33.0 35.3 38.6 39.3 39.6 37.0 36.8 38.5 37.9 37.4 39.3 37.8 34.2 31.4 30.4
9.0 34.0 34.4 36.4 39.4 41.2 43.7 44.5 48.0 48.5 50.3 51.3 50.0 48.5 49.1 50.2 49.5 47.8 45.0 42.6 38.6 39.7
8.5 40.4 42.8 46.5 49.5 50.5 55.0 58.7 61.3 62.0 61.9 66.7 66.1 64.4 62.8 65.7 65.2 62.0 58.4 57.6 55.5 51.1
8.0 54.6 59.7 64.4 63.2 69.2 74.6 77.7 78.2 78.3 83.9 85.0 83.5 80.8 83.2 84.1 80.1 74.8 73.4 73.7 68.4 64.1
7.5 68.6 70.0 78.1 81.7 80.5 88.8 94.6 97.3 96.4 98.6 104 106 103 101 104 104 96.4 92.0 92.6 92.1 85.5
7.0 86.7 92.7 101 98.8 103 112 118 116 118 121 128 125 123 124 127 120 112 113 113 110 103
6.5 106 111 120 120 121 130 138 137 138 141 145 149 145 144 147 146 138 133 135 133 127
6.0 129 136 143 141 144 154 159 159 161 164 170 168 166 168 169 166 159 155 156 152 145
AZIMUTH, deg
250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270
20.0 17.5 17.6 17.3 17.6 17.3 17.4 17.4 17.5 17.4 17.4 17.4 17.4 17.4 17.4 17.3 17.5 17.5 17.4 17.3 17.4 17.6
19.0 18.2 18.2 18.2 18.1 18.1 18.2 18.0 18.1 18.0 18.0 18.0 18.1 18.1 18.0 18.0 17.9 17.9 17.9 17.9 17.8 18.0
18.0 18.7 18.9 18.8 18.8 18.9 18.8 18.8 18.7 18.6 18.6 18.6 18.6 18.6 18.6 18.5 18.6 18.5 18.6 18.5 18.5 18.6
17.0 19.5 19.3 19.1 19.5 19.4 19.3 19.2 19.2 19.1 19.2 19.3 19.2 19.2 19.2 18.9 19.0 19.1 19.2 19.0 19.0 19.0
16.0 20.3 20.3 20.2 20.2 20.0 20.1 20.1 20.1 20.0 20.0 20.0 19.9 20.0 19.9 19.9 19.8 19.9 19.8 19.7 19.8 19.4
15.0 20.9 20.8 21.0 21.0 20.9 20.9 20.9 20.8 20.8 20.9 20.9 20.9 20.9 20.8 20.6 20.7 20.7 20.5 20.5 20.6 20.4
14.0 21.7 21.8 21.9 21.6 21.8 21.7 21.7 21.7 21.7 21.8 21.5 21.7 21.7 21.7 21.5 21.4 21.5 21.4 21.5 21.4 21.5
13.0 22.5 22.7 22.6 22.6 22.6 22.6 22.6 22.6 22.6 22.5 22.6 22.6 22.6 22.5 22.4 22.4 22.3 22.3 22.5 22.2 22.5
12.0 23.7 23.8 23.7 23.8 23.6 23.6 23.7 23.6 23.6 23.5 23.5 23.6 23.5 23.6 23.5 23.4 23.4 23.3 23.4 23.3 23.0
11.0 25.0 25.1 25.1 24.9 24.9 24.8 24.8 24.8 24.6 24.7 24.7 24.4 24.6 24.5 24.5 24.4 24.5 24.4 24.3 24.3 24.3
10.5 25.7 25.7 25.7 25.6 25.5 25.3 25.4 25.3 25.2 25.3 25.1 25.2 25.0 25.0 24.9 24.9 25.0 24.9 24.9 24.8 24.7
10.0 27.1 27.5 27.4 26.5 26.7 26.5 26.1 25.9 25.9 25.8 25.7 25.8 25.7 25.7 25.6 25.6 25.8 25.6 25.5 25.4 25.3
9.5 30.4 32.1 33.2 30.6 29.3 30.2 28.6 27.2 26.7 26.7 26.6 26.4 26.4 26.5 26.3 26.2 26.3 26.2 26.2 26.1 25.8
9.0 39.7 41.0 38.4 35.8 35.6 33.3 30.1 28.3 27.8 27.5 27.4 27.3 27.3 27.1 27.0 26.9 27.1 27.0 26.9 26.9 27.0
8.5 51.1 50.5 48.8 48.4 46.3 40.9 36.3 35.3 31.3 29.2 28.4 28.3 28.1 28.0 27.8 27.8 27.8 27.8 27.7 27.7 27.5
8.0 64.1 62.9 64.0 61.1 55.9 48.5 47.5 43.9 37.2 31.9 29.7 29.2 29.1 28.8 29.1 28.7 28.8 28.6 28.8 28.6 28.5
7.5 85.5 81.1 80.2 80.4 76.0 68.0 63.1 59.9 51.8 43.3 36.1 32.1 30.6 30.4 30.2 30.1 30.2 30.0 30.2 29.8 30.0
7.0 103 98.4 98.6 97.8 91.3 82.9 79.6 71.7 61.1 52.0 43.8 36.9 33.9 32.5 31.6 31.3 31.3 31.2 31.1 31.2 31.2
6.5 127 119 118 119 115 105 101 93.9 81.0 71.1 61.7 52.4 44.8 40.8 35.9 33.9 33.3 32.9 32.8 32.8 32.8
6.0 145 140 140 141 132 125 120 109 96.1 86.0 76.4 65.8 57.0 52.2 45.1 39.0 37.2 37.5 36.9 35.7 35.4
Table 9. DSS 63 Eastern Horizon S-Band Top (K) with SPD Cone
ELEV, AZIMUTH, deg
deg 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130
40.0 18.4 18.6 18.5 18.4 18.5 18.3 18.1 18.1 18.1 18.1 18.1 18.3 18.3 18.4 18.2 18.1 18.2 18.2 18.2 18.2 18.2
35.0 18.7 18.7 18.8 18.7 18.7 18.7 18.6 18.6 18.6 18.6 18.5 18.5 18.5 18.5 18.5 18.4 18.5 18.5 18.5 18.5 18.6
30.0 18.9 19.0 19.1 19.0 19.0 19.0 18.9 19.1 19.0 19.0 19.0 19.1 19.0 19.0 19.2 19.1 19.1 19.1 19.3 19.2 19.1
25.0 20.0 19.9 20.1 20.1 20.1 20.1 20.1 20.0 20.0 20.0 19.9 19.9 20.0 19.9 19.8 19.7 19.8 19.8 19.8 19.8 19.9
20.0 21.5 21.5 21.6 21.7 21.6 21.7 21.7 21.8 21.7 21.6 21.4 21.4 21.4 21.5 21.7 21.8 21.8 21.7 21.5 21.5 21.6
19.0 21.8 21.8 21.9 21.9 21.9 21.9 21.9 21.9 21.9 22.0 22.1 22.1 22.3 22.0 22.1 21.9 21.9 21.8 21.7 21.9 21.9
18.0 22.8 22.9 22.9 23.2 23.3 23.0 23.1 23.0 22.9 23.0 22.8 23.0 22.9 23.0 23.0 22.9 22.8 22.9 22.7 22.7 22.6
17.0 22.8 22.8 22.8 23.0 22.8 22.7 22.9 22.9 22.8 23.0 23.0 22.9 23.1 23.0 22.9 23.0 23.1 22.9 22.8 23.0 23.0
16.0 23.9 24.1 24.2 24.1 23.8 24.0 24.0 23.9 23.7 23.6 23.7 23.5 23.5 23.7 23.6 23.5 23.6 23.5 23.4 23.4 23.6
15.0 24.4 24.4 24.4 24.4 24.5 24.4 24.4 24.3 24.4 24.2 24.5 24.4 24.5 24.6 24.7 24.7 24.7 24.7 24.7 24.8 24.7
14.0 25.0 24.9 25.1 25.1 25.1 25.1 25.3 25.3 25.2 25.3 25.3 25.3 25.3 25.3 25.2 25.2 25.3 25.2 25.3 25.3 25.3
13.0 26.2 26.2 26.2 26.2 26.2 26.3 26.2 26.3 26.3 26.4 26.3 26.2 26.3 26.4 26.3 26.3 26.0 26.0 26.1 26.2 26.2
12.0 27.4 27.5 27.6 27.4 27.3 27.4 27.3 27.4 27.3 27.1 27.3 27.1 27.1 27.2 27.2 27.2 27.3 27.4 27.5 27.5 27.4
11.0 28.1 28.2 28.1 28.1 27.9 27.9 28.0 28.0 27.9 28.0 28.1 28.0 27.9 28.0 27.7 28.0 28.1 28.2 28.0 28.0 27.7
10.0 30.2 30.1 29.9 30.0 29.8 29.9 29.7 29.8 29.6 29.4 29.3 29.3 29.2 29.1 29.0 29.0 29.2 29.1 29.2 29.3 29.2
9.5 30.3 30.3 30.3 30.2 30.2 30.0 30.2 30.0 30.1 30.1 29.8 29.7 29.5 29.5 29.4 29.4 29.6 29.5 29.4 29.5 29.5
9.0 30.3 30.3 30.6 30.1 30.1 30.3 30.2 30.3 30.4 30.2 30.0 30.0 29.8 29.8 29.8 29.8 29.9 29.8 30.0 30.1 30.1
8.5 31.1 31.3 31.1 30.9 30.8 30.7 30.8 30.9 31.1 31.1 31.3 31.2 31.1 31.1 31.1 31.1 31.2 31.0 31.0 31.0 31.2
8.0 32.2 32.5 32.6 32.4 32.6 32.4 32.6 32.3 32.6 32.4 32.3 32.3 32.5 32.5 32.6 32.5 32.5 32.4 32.4 32.3 32.2
7.5 33.2 33.4 33.4 33.2 33.2 33.3 33.5 33.5 33.6 33.5 33.4 33.3 33.4 33.6 33.5 33.5 33.4 33.4 33.4 33.4 33.3
7.0 34.6 34.6 34.5 34.3 34.4 34.4 34.5 34.4 34.6 34.6 34.6 34.7 34.6 34.8 34.7 34.3 34.6 34.6 34.5 34.7 34.8
6.5 35.8 36.3 36.0 36.2 35.9 36.0 36.0 35.8 35.9 35.9 35.9 35.9 35.8 35.7 36.1 35.8 35.6 35.7 35.6 35.8 35.8
6.0 37.5 37.6 37.6 37.5 37.6 37.5 37.5 37.3 37.2 37.2 37.3 37.4 37.2 37.2 37.3 37.2 37.1 37.0 37.2 37.0 37.1
AZIMUTH, deg
130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150
40.0 18.2 18.3 18.3 18.3 18.3 18.3 18.3 18.4 18.4 18.4 18.1 18.0 18.1 18.1 18.2 18.2 18.4 18.5 18.5 18.3 18.3
35.0 18.6 18.5 18.5 18.7 18.7 18.7 18.9 18.9 18.9 18.8 18.7 18.6 18.5 18.4 18.5 18.5 18.6 18.7 18.7 18.8 18.8
30.0 19.1 19.2 19.1 19.3 19.1 19.2 19.3 19.3 19.2 19.3 19.1 19.1 19.0 19.2 19.1 19.0 19.2 19.1 19.2 19.2 19.1
25.0 19.9 19.9 20.0 20.0 20.1 20.1 20.2 20.1 20.0 20.0 20.0 19.9 19.9 19.9 19.9 19.9 19.7 19.8 20.1 20.1 20.0
20.0 21.6 21.6 21.7 21.6 21.7 21.8 21.8 21.8 21.9 21.6 21.7 21.8 21.7 21.7 21.6 21.6 21.7 21.9 21.8 21.7 21.7
19.0 21.9 22.0 22.0 22.0 21.9 22.0 22.3 22.1 22.2 22.1 22.0 22.0 22.0 22.1 22.1 22.3 22.3 22.2 22.3 22.2 22.1
18.0 22.6 22.6 22.7 22.4 22.7 22.7 22.6 22.7 22.8 22.8 22.8 22.8 22.8 22.6 22.6 22.5 22.4 22.6 22.7 22.7 22.6
17.0 23.0 22.9 22.9 22.8 22.9 22.9 22.9 22.8 22.9 22.9 23.1 23.2 23.4 23.5 23.5 23.5 23.5 23.4 23.4 23.5 23.5
16.0 23.6 23.5 23.5 23.3 23.2 23.3 23.4 23.7 23.6 23.7 23.8 23.8 23.7 23.7 23.8 24.0 23.8 23.9 24.1 24.3 24.1
15.0 24.7 24.6 24.5 24.7 24.8 24.7 24.6 24.6 24.6 24.5 24.3 24.2 24.1 24.4 24.6 24.4 24.5 24.4 24.3 24.3 24.3
14.0 25.3 25.3 25.4 25.5 25.3 25.2 25.4 25.3 25.2 25.3 25.3 25.4 25.4 25.4 25.6 25.5 25.5 25.6 25.3 25.3 25.2
13.0 26.2 26.1 26.1 26.3 26.4 26.3 26.2 26.4 26.3 26.3 26.3 26.4 26.2 26.1 26.1 26.1 26.2 26.4 26.3 26.3 26.3
12.0 27.4 27.3 27.4 27.5 27.2 27.4 27.2 27.4 27.1 27.2 27.0 27.0 26.9 27.1 26.9 27.1 26.8 26.9 26.8 27.0 27.2
11.0 27.7 28.0 28.1 27.9 27.8 27.9 28.1 28.2 28.6 28.7 28.6 28.7 28.8 28.9 28.9 28.8 28.8 28.7 28.9 28.8 28.7
10.0 29.2 29.3 29.1 29.2 29.3 29.2 29.3 29.4 29.3 29.3 29.2 29.1 29.2 29.2 29.1 29.1 29.1 29.2 29.3 29.3 29.4
9.5 29.5 29.3 29.5 29.5 29.2 29.5 29.4 29.2 29.5 29.5 29.2 29.1 29.4 29.2 29.2 29.4 29.3 29.4 29.4 29.3 29.4
9.0 30.1 30.2 30.3 30.3 30.6 30.4 30.4 30.6 30.6 30.6 30.4 30.4 30.6 30.6 30.5 30.4 30.5 30.4 30.1 30.3 30.1
8.5 31.2 31.1 30.9 31.0 30.9 30.7 30.6 30.4 30.3 30.2 30.5 30.5 30.6 30.5 30.3 30.2 30.2 30.3 30.4 30.5 30.7
8.0 32.2 31.9 31.7 31.9 31.8 31.9 31.8 31.7 31.6 31.5 31.5 32.0 31.6 31.5 31.3 31.8 31.8 31.4 31.5 31.3 31.1
7.5 33.3 33.4 33.3 33.1 33.1 33.0 32.9 32.5 32.8 32.6 32.8 32.7 32.8 32.9 32.8 32.8 32.7 32.6 32.7 32.7 32.7
7.0 34.8 34.6 34.7 34.6 34.5 34.3 34.3 34.1 34.1 34.1 33.9 33.8 33.8 33.8 34.2 33.8 33.8 33.6 33.6 33.3 33.3
6.5 35.8 35.8 35.7 35.7 35.8 35.6 35.7 35.6 35.7 35.5 35.4 35.5 35.4 35.6 35.6 35.4 35.4 35.3 35.2 35.2 35.2
6.0 37.1 37.0 37.1 37.1 37.1 36.8 36.8 36.7 36.8 36.7 36.9 36.8 36.6 36.7 36.7 36.5 36.7 36.2 36.2 36.1 36.1
Table 10. DSS 63 Western Horizon S-Band Top (K) with SPD Cone
ELEV, AZIMUTH, deg
deg 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230
40.0 26.2 20.4 19.6 19.7 19.4 19.6 20.2 20.5 21.6 26.6 22.3 20.2 19.6 19.5 19.1 19.1 19.2 19.2 19.3 19.2 19.1
35.0 19.5 19.5 19.9 19.8 20.0 20.2 20.4 20.7 22.0 25.8 21.6 20.6 20.3 20.1 19.9 19.8 19.7 19.7 19.6 19.7 19.7
30.0 20.4 20.6 20.7 20.9 21.0 21.8 24.2 22.9 21.9 21.5 21.0 20.8 20.8 20.7 20.6 20.5 20.5 20.5 20.4 20.4 20.2
25.0 21.2 21.3 21.2 21.5 21.7 23.0 26.6 24.4 22.6 22.1 21.8 21.5 21.3 21.4 21.2 21.1 21.1 21.1 21.1 21.1 20.9
20.0 22.9 23.4 23.7 24.0 25.5 26.4 24.6 23.8 23.5 23.1 23.0 22.7 22.8 22.7 22.6 22.4 22.4 22.4 22.6 22.7 22.5
19.0 23.5 23.6 23.8 24.3 25.7 27.4 25.5 24.6 24.0 23.6 23.3 23.2 23.4 23.0 23.2 23.0 23.0 22.9 22.9 23.0 22.9
18.0 24.3 25.0 28.2 30.5 26.1 25.3 24.5 24.2 23.8 23.7 23.6 23.6 23.5 23.6 23.4 23.4 23.4 23.4 23.4 23.4 23.5
17.0 24.8 25.0 27.3 27.3 26.8 25.7 24.9 24.7 24.5 24.2 24.2 24.1 24.0 24.0 24.0 24.0 24.0 24.0 23.9 24.0 23.9
16.0 25.8 27.2 28.0 26.6 25.7 25.4 24.9 24.7 24.6 24.6 24.5 24.8 24.8 24.8 24.6 24.7 24.6 24.6 24.7 24.7 24.5
15.0 27.1 27.8 29.8 27.6 27.3 26.4 25.7 25.5 25.6 25.4 25.3 25.6 25.3 25.3 25.3 26.0 27.6 25.5 25.1 25.2 25.0
14.0 29.5 35.3 28.7 26.9 26.6 26.3 26.3 26.0 26.2 26.0 26.1 26.1 26.0 26.1 26.2 26.0 26.0 26.0 26.1 26.0 26.1
13.0 35.0 42.1 30.3 28.1 27.5 27.4 27.0 26.8 27.0 26.8 26.8 26.9 26.7 26.8 26.9 27.0 26.9 26.8 26.9 26.8 26.8
12.0 30.7 29.6 28.6 28.2 27.9 27.9 27.7 27.5 27.7 27.5 27.5 27.5 27.5 27.5 27.5 27.6 27.7 27.8 27.7 27.8 27.8
11.0 31.3 30.8 29.8 29.2 28.9 28.7 28.4 28.4 28.6 28.5 28.5 28.6 28.5 28.5 28.5 28.4 28.4 28.7 28.6 28.6 28.6
10.0 29.8 29.9 29.8 29.6 29.5 29.4 29.3 29.4 29.3 29.4 29.5 29.4 29.3 29.7 29.5 29.5 29.4 29.5 29.5 29.7 29.7
9.5 30.6 30.4 30.2 30.3 30.1 30.1 30.1 30.1 30.2 30.1 30.3 30.3 30.0 30.0 30.6 30.3 30.1 30.3 30.4 30.2 30.2
9.0 30.9 30.9 30.8 30.7 30.9 30.6 30.8 30.7 30.8 30.7 31.1 30.8 30.7 30.7 30.9 30.8 30.9 30.7 31.1 30.8 31.0
8.5 31.5 31.5 31.4 31.6 31.7 31.5 31.4 31.5 31.4 31.4 31.3 31.3 31.2 31.2 31.3 31.3 31.2 31.4 31.3 31.3 31.3
8.0 32.3 32.1 31.9 32.3 32.1 32.1 32.2 31.9 32.4 32.2 32.3 32.2 32.4 32.3 32.0 32.2 32.4 32.4 32.4 32.5 32.5
7.5 33.1 33.2 32.9 33.5 33.0 33.0 33.3 33.0 32.9 33.4 33.2 33.3 33.2 33.1 33.4 33.5 33.2 33.3 33.2 33.2 33.5
7.0 33.9 34.5 33.8 34.3 34.3 34.1 34.0 34.0 34.3 34.3 34.6 34.3 34.3 34.5 34.7 34.8 34.6 34.7 34.7 34.5 34.5
6.5 34.4 34.2 34.7 34.8 34.7 34.8 34.4 34.5 34.4 34.8 34.5 34.9 34.8 34.7 35.0 35.2 35.2 35.3 35.2 35.2 35.4
6.0 35.4 35.3 35.7 36.2 35.5 35.9 35.8 35.8 36.1 36.6 36.7 36.3 36.8 36.9 36.9 37.0 37.1 36.9 37.2 37.3 37.1
AZIMUTH, deg
230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250
40.0 19.1 19.0 18.9 18.9 18.9 18.8 18.8 18.8 18.9 18.8 18.8 18.9 18.9 18.9 18.9 18.9 18.9 18.9 18.9 18.9 19.0
35.0 19.7 19.5 19.6 19.4 19.3 19.5 19.4 19.3 19.5 19.4 19.2 19.2 19.4 19.4 19.2 19.1 19.2 19.3 19.4 19.2 19.2
30.0 20.2 20.3 20.2 20.2 20.3 20.2 20.2 20.1 20.1 20.0 20.1 20.0 19.9 20.0 20.0 20.1 20.1 20.0 20.2 20.2 20.2
25.0 20.9 20.9 21.2 21.1 20.8 20.9 20.9 20.9 20.9 20.9 21.0 21.0 21.0 21.0 21.1 21.1 21.1 21.1 21.1 21.1 21.0
20.0 22.5 22.6 22.7 22.5 22.6 22.6 22.5 22.9 22.7 22.7 22.6 22.5 22.5 22.5 22.6 22.6 22.6 22.6 22.6 22.7 22.8
19.0 22.9 23.0 23.0 23.0 23.0 23.0 23.0 23.0 23.0 23.2 23.1 23.2 23.2 23.1 23.1 23.1 23.1 23.1 23.2 23.2 23.2
18.0 23.5 23.5 23.5 23.5 23.6 23.6 23.7 23.7 23.7 23.8 23.8 23.9 23.8 23.7 23.7 23.7 23.7 23.7 23.8 23.8 23.8
17.0 23.9 23.9 24.1 24.1 24.1 24.1 24.1 24.1 24.3 24.3 24.3 24.3 24.2 24.2 24.2 24.2 24.2 24.2 24.2 24.3 24.3
16.0 24.5 24.6 24.7 24.7 24.7 24.8 24.8 24.8 24.8 24.9 24.7 24.7 24.6 24.6 24.7 24.8 24.9 24.8 24.9 24.9 24.9
15.0 25.0 25.2 25.2 25.2 25.1 25.3 25.2 25.3 25.3 25.3 25.6 25.4 25.5 25.5 25.5 25.6 25.6 25.6 25.5 25.7 25.6
14.0 26.1 26.0 26.1 26.1 26.2 26.2 26.2 26.3 26.2 26.3 26.4 26.3 26.3 26.3 26.4 26.4 26.4 26.5 26.6 26.5 26.6
13.0 26.8 26.9 26.8 26.8 26.8 26.9 26.9 26.9 26.9 27.0 27.0 27.0 27.1 27.1 27.1 27.1 27.1 27.1 27.2 27.2 27.3
12.0 27.8 27.6 27.7 27.7 27.8 27.8 27.8 27.8 27.9 28.0 27.9 27.9 27.9 27.9 28.0 28.0 28.0 28.1 28.1 28.2 28.2
11.0 28.6 28.6 28.5 28.5 28.6 28.5 28.6 28.8 28.7 28.7 28.9 28.8 28.8 28.8 28.8 28.9 28.9 28.9 28.9 29.0 29.0
10.0 29.7 29.5 29.5 29.5 29.6 29.6 29.6 29.7 29.8 29.9 29.8 29.8 29.9 29.9 30.0 30.0 30.0 30.0 30.1 30.1 30.1
9.5 30.2 30.4 30.3 30.3 30.3 30.3 30.2 30.5 30.4 30.4 30.6 30.5 30.6 30.6 30.6 30.7 30.8 30.7 30.6 30.7 30.7
9.0 31.0 30.8 31.0 30.9 31.1 31.0 31.0 31.1 31.1 31.3 31.2 31.3 31.4 31.3 31.4 31.4 31.4 31.4 31.4 31.5 31.6
8.5 31.3 31.3 31.5 31.5 31.4 31.5 31.6 31.7 31.6 31.8 31.8 32.0 31.8 31.9 32.1 32.0 32.2 32.2 32.3 32.3 32.4
8.0 32.5 32.4 32.5 32.4 32.3 32.5 32.7 32.7 32.8 32.9 32.8 32.9 32.9 33.0 32.9 33.0 33.1 33.2 33.3 33.3 33.5
7.5 33.5 33.3 33.1 33.3 33.4 33.5 33.6 33.6 33.8 33.9 34.0 33.9 34.1 34.3 34.2 34.7 34.5 34.6 34.5 34.6 34.7
7.0 34.5 34.6 34.5 34.5 34.5 34.7 34.5 34.6 34.7 34.9 35.1 35.4 35.4 35.5 35.6 35.8 36.1 36.3 36.5 36.4 36.5
6.5 35.4 35.4 35.4 35.7 36.0 35.9 36.0 35.8 35.3 35.7 35.8 36.2 36.5 36.8 37.2 37.9 39.0 42.3 45.9 44.5 39.2
6.0 37.1 37.2 37.1 37.0 37.3 37.3 37.2 37.5 37.5 37.9 38.4 39.2 41.6 47.5 49.4 57.4 89.6 113 122 118 105
Table 11. Recommended Minimum Operating Carrier Signal Levels (dBm)+
Band, LNA, and Receiver Effective Noise Bandwidth (BL) (Hz)*
Configuration 0.25 1.0 2.0 20.0 200
L-Band
LNA-1 or 2 -181.4 -175.4 -172.3 -162.3 -152.3
S-Band Ultracone
DSS 43 -183.9 -177.9 -174.9 -164.9 -154.9
S-Band LNA-1, Non-diplexed
DSS 14 -182.8 -176.8 -173.8 -163.8 -153.8
DSS 43 -182.7 -176.7 -173.7 -163.7 -153.7
DSS 63 -182.3 -176.3 -173.3 -163.3 -153.3
S-Band LNA-1, Diplexed
DSS 14 -181.7 -175.7 -172.7 -162.7 -152.7
DSS 43 -181.6 -175.6 -172.6 -162.6 -152.6
DSS 63 -181.4 -175.3 -172.3 -162.3 -152.3
S-Band LNA-2, Non-diplexed
DSS 14 -181.6 -175.5 -172.5 -162.5 -152.5
DSS 43 -181.5 -175.5 -172.5 -162.5 -152.5
DSS 63 -181.2 -175.2 -172.2 -162.2 -152.2
S-Band LNA-2, Diplexed
DSS 14 -180.7 -174.7 -171.7 -161.7 -151.7
DSS 43 -180.7 -174.6 -171.6 -161.6 -151.6
DSS 63 -180.4 -174.4 -171.4 -161.4 -151.4
X-Band LNA-1 and LNA 2, S/X
Dichroic In-place
DSS 14 (XTR feedcone) -182.2 -176.2 -173.2 -163.2 -153.2
DSS 43 (XTR feedcone) -182.1 -176.1 -173.1 -163.1 -153.1
DSS 63 (XRO feedcone) -181.4 -175.4 -172.4 -162.4 -152.4
X-Band LNA-1 and LNA 2, S/X
Dichroic Retracted
DSS 14 -182.4 -176.4 -173.4 -163.4 -153.4
DSS 43 -182.3 -176.3 -173.3 -163.3 -153.3
+ Levels are referenced to LNA input terminals with nominal zenith system noise,
including 25% weather.
* Bandwidths are centered about the received carrier.
Figure 1. Functional Block Diagram of DSS 14 and DSS 43 Microwave and Transmitter Equipment
(Figure omitted from text-only version of document)
Figure 2. Functional Block Diagram of DSS 63 Microwave and Transmitter Equipment
(Figure omitted from text-only version of document)
Figure 3. S-Band Receive Gain Versus Elevation Angle, All Stations
(Figure omitted from text-only version of document)
Figure 4. Predicted X-Band Receive Gain Versus Elevation Angle, DSS 14
(Figure omitted from text-only version of document)
Figure 5. Predicted X-Band Receive Gain Versus Elevation Angle, DSS 43
(Figure omitted from text-only version of document)
Figure 6. X-Band Receive Gain Versus Elevation Angle, DSS 63 Antenna
(Figure omitted from text-only version of document)
Figure 7. L-Band System Noise Temperature, All Stations
(Figure omitted from text-only version of document)
Figure 8. S-Band System Noise Temperature Versus Elevation Angle, DSS 14,
(Figure omitted from text-only version of document)
Figure 9. Eastern Horizon S-Band System Noise Temperature at 6 degree Elevation Angle
(Figure omitted from text-only version of document)
Figure 10. Western Horizon S-Band System Noise Temperature at 6 degree Elevation Angle
(Figure omitted from text-only version of document)
Figure 11. Predicted X-Band System Noise Temperature Versus Elevation Angle,
(Figure omitted from text-only version of document)
Figure 12. Predicted X-Band System Noise Temperature Versus Elevation Angle,
(Figure omitted from text-only version of document)
Figure 13. X-Band System Noise Temperature Versus Elevation Angle, DSS 63
(Figure omitted from text-only version of document)
Figure 14. L-Band and S-Band Pointing Loss Versus Pointing Error
(Figure omitted from text-only version of document)
Figure 15. X-Band Pointing Loss Versus Pointing Error
(Figure omitted from text-only version of document)
Appendix A
Equations for Modeling
A.1 Equations for Gain Versus Elevation Angle
The following equation can be used to generate L-band receive, S-band transmit,
and S-band receive gain versus elevation angle curves for all stations and X-band receive gain
versus elevation angle curves for DSS 63. Examples of these curves are shown in Figures 3 and
6. See paragraph 2.1.1.1 for frequency effect modeling and module 105 for atmospheric
attenuation at weather conditions other than 0%, 50%, and 90% cumulative distribution.
G(theta) = G_0 - G_1(cos(gamma) - cos(theta))^2
- G_2(sin(gamma) - sin(theta))^2 - A_ZEN/sin(theta), dBi (1)
where
theta = antenna elevation angle (deg.) 6 <= theta <= 90
G_0, G_1, G_2, gamma = parameters from Table A-1
A_ZEN = zenith atmospheric attenuation, dB, from Table A-2 or from Table 2 in module 105.
The following equation can be used to generate X-band transmit and receive gain
versus elevation curves for DSS 14 and DSS 43. Examples of these curves are shown in Figures
4 and 5. See paragraph 2.1.1.1 for frequency effect modeling and module 105 for atmospheric
attenuation at weather conditions other than 0%, 50%, and 90% cumulative distribution.
G(theta) = G_0 - G_1(theta - gamma)^2 - A_ZEN/sin(theta), dBi (2)
where
theta = antenna elevation angle (deg.) 6 <= theta <= 90
G_0, G_1, gamma = parameters from Table A-1
A_ZEN = zenith atmospheric attenuation, dB, from Table A-2 or from Table 2 in module 105.
A.2 Equations for System Temperature Versus Elevation Angle
The following equation can be used to generate L-band and S-band system
temperature versus elevation angle curves for all stations and X- band system temperature versus
elevation angle for DSS 63. Examples of these curves are shown in Figures 7, 8, and 13. See
module 105 for atmospheric attenuation at weather conditions other than 0%, 50%, and 90%
cumulative distribution.
T_op(theta) = T_1 + T_2 * exp(-a/(90.001-theta)) + (255 + 25CD)(1 - 1/(10^(A_ZEN/(10sin(theta))))), K (3)
where
theta = antenna elevation angle (deg.), 6 <= theta <= 90
T_1, T_2, a = parameters from Table A-3
CD = cumulative distribution used to select A_ZEN from Table A-2 or from Table 2 in module 105, 0 < CD < 0.99
A_ZEN = zenith atmospheric attenuation for selected CD from Table A-2 or from Table 2 in module 105, dB.
The following equation can be used to generate X-band system temperature
versus elevation curves for DSS 14 and DSS 43. Examples of these curves were shown in
Figures 11 and 12. See module 105 for atmospheric attenuation at weather conditions other than
0%, 50%, and 90% cumulative distribution.
T_op(theta) = T_1 + T_2 * exp(a * theta) + (255 + 25CD)(1 - 1/(10^(A_ZEN/(10sin(theta))))), K (4)
where
theta = antenna elevation angle (deg.), 6 <= theta <= 90
T_1, T_2, a = parameters from A-3
CD = cumulative distribution used to select A_ZEN from Table A-2 or from Table 2 in module 105, 0 < CD < 0.99
A_ZEN = zenith atmospheric attenuation for selected CD from Table A-2 or from Table 2 in module 105, dB.
A.3 Equation for Gain Reduction Versus Pointing Error
The following equation can be used to generate gain-reduction versus pointing
error curves, examples of which are depicted in Figures 14 and 15.
delta G(theta) = 10log(exp((2.773 * theta^2)/HPBW^2)), dBi
where
theta = pointing error
HPBW = half-power beamwidth in degrees (from Tables 1 or 2).
Table A-1. Vacuum Component of Gain Parameters
Configuration and Stations Parameters
G0 (Transmit) G0 (Receive) G1 G2 gamma
L-Band, All Stations - 60.01 0.088 0.104 46.27
S-Band, All Stations 62.7 63.34 0.088 0.104 46.27
X-Band, S/X Configuration*
DSS 14 72.9 74.1 0.00021 - 45.0
DSS 43 72.9 74.1 0.00045 - 45.0
DSS 63 - 74.28 1.49 1.766 46.83
X-Band, X-Only Configuration*
DSS 14 72.9 74.3 0.00021 - 45.0
DSS 43 72.9 74.3 0.00045 - 45.0
Notes:
* DSS 14 and DSS 43 X-band parameters are for predicted performance. Model for DSS 14
and DSS 43 X-band performance is different from model used for other frequency bands and
for DSS 63. See Equations (1) and (2).
+ G_0 values are nominal at the frequency specified in Table 1 or Table 2. Other parameters
apply to all frequencies within the same band.
Table A-2. Zenith Atmosphere Attenuation Above Vacuum (A_ZEN)
Weather Condition+ A_ZEN, dB*
L-Band S-Band X-Band
All Stations All Stations DSS 14 DSS 43 DSS 63
Vacuum 0.000 0.000 0.000 0.000 0.000
CD = 0.00 0.034 0.034 0.037 0.040 0.038
CD = 0.50 0.033 0.033 0.040 0.048 0.045
CD = 0.90 0.033 0.033 0.047 0.059 0.053
Notes:
* From Table 2 in module 105, L- and S-band values are average for all stations.
+ CD = cumulative distribution.
Table A-3. Vacuum Component of System Noise Temperature Parameters
Configuration and Stations Parameters
T1 T2 a
L-Band, All Stations 19.0 101.95 285
S-Band, DSS 14, SPD Cone, Non-diplexed+ 13.35 101.95 285
S-Band, DSS 43, SPD Cone, Non-diplexed+ 13.75 101.95 285
S-Band, DSS 63, SPD Cone, Non-diplexed+ 15.05 101.95 285
S-Band, DSS 14, SPD Cone, Diplexed+ 17.65 101.95 285
S-Band, DSS 43, SPD Cone, Diplexed+ 14.05 101.95 285
S-Band, DSS 63, SPD Cone, Diplexed+ 19.35 101.95 285
S-Band, DSS 43, Ultracone 9.78 101.95 285
X-Band, DSS 14, X-Only Configuration 14.2 6.8 0.065
X-Band, DSS 14, S/X Configuration 15.1 6.8 0.065
X-Band, DSS 43, X-Only Configuration 14.56 6.4 0.07
X-Band, DSS 43, S/X Configuration 15.78 10.0 0.10
X-Band, DSS 63, S/X Configuration 18.39 122.43 241.5
Notes:
* Model for DSS 14 and DSS 43 X-band System Noise Temperature, Equation (4), is different
from model used at other frequency bands and for DSS 63, Equation (3).
+ S-band noise temperature parameters are for LNA 1. Increase T1 by 5.0 K for LNA-2
810-005, Rev. E
DSMS Telecommunications Link
Design Handbook
103
34-m HEF Subnet
Telecommunications Interfaces
Effective November 30, 2000
Document Owner: Approved by:
----------------------- -----------------------
S.D. Slobin Date A.J. Freiley Date
Antenna System Engineer Antenna Product Domain Service
System Development Engineer
Released by:
[Signature on file in TMOD Library]
----------------------------------
TMOD Document Release Date
Change Log
Rev Issue Date Affected Paragraphs Change Summary
Initial 1/15/2001 All All
Note to Readers
There are two sets of document histories in the 810-005 document, and these
histories are reflected in the header at the top of the page. First, the entire document is
periodically released as a revision when major changes affect a majority of the modules. For
example, this module is part of 810-005, Revision E. Second, the individual modules also
change, starting as an initial issue that has no revision letter. When a module is changed, a
change letter is appended to the module number on the second line of the header and a summary
of the changes is entered in the module's change log.
This module supersedes TCI-30 in 810-005, Rev. D.
810-005, Rev. E
103
3
Contents
Paragraph Page
1 Introduction ......................................................................................... 4
1.1 Purpose............................................................................................. 4
1.2 Scope .............................................................................................. 4
2 General Information .................................................................................. 4
2.1 Telecommunications Parameters....................................................................... 4
2.1.1 Antenna Gain Variation ........................................................................... 5
2.1.1.1 Frequency Effects............................................................................... 5
2.1.1.2 Elevation Angle Effects ........................................................................ 5
2.1.1.3 Wind Loading.................................................................................... 5
2.1.2 System Noise Temperature Variation................................................................ 5
2.1.3 Pointing Accuracy ................................................................................ 6
2.2 Recommended Minimum Operating Carrier Signal Levels................................................. 6
3 Proposed Capabilities................................................................................. 6
3.1 S-Band LNA Enhancement.............................................................................. 6
Appendix A, Equations for Modeling .................................................................... 21
A.1 Equation for Gain Versus Elevation Angle........................................................... 21
A.2 Equation for System Temperature Versus Elevation Angle ............................................ 21
A.3 Equation for Gain Reduction Versus Pointing Error ................................................. 21
Illustrations
Figure Page
1. Functional Block Diagram of Microwave and Transmitter Subsystem..................................... 15
2. S-Band Receive Gain Versus Elevation Angle, All HEF Antennas ....................................... 16
3. X-Band Receive Gain Versus Elevation Angle, DSS 15 Antenna, Non-Diplexed Path, Maser LNA Input ..... 16
4. X-Band Receive Gain Versus Elevation Angle, DSS 45 Antenna, Non-Diplexed Path, Maser LNA Input ..... 17
5. X-Band Receive Gain Versus Elevation Angle, DSS 65 Antenna, Non-Diplexed Path, Maser LNA Input ..... 17
6. S-Band System Temperature vs. Elevation Angle, Average for DSS 15 and 45 Antennas at LNA Input ..... 18
7. S-Band System Temperature vs. Elevation Angle, DSS 65 at LNA Input ................................. 18
8. X-Band System Temperature vs. Elevation Angle, DSS 15 Antenna, Non-Diplexed Path, Maser LNA Input .. 19
9. X-Band System Temperature vs. Elevation Angle, DSS 45 Antenna, Non-Diplexed Path, Maser LNA Input .. 19
10. X-Band System Temperature vs. Elevation Angle, DSS 65 Antenna, Non-Diplexed Path, Maser LNA Input . 20
11. S-Band Gain Reduction Versus Angle Off Boresight................................................... 20
12. X-Band Gain Reduction Versus Angle Off Boresight .................................................. 21
Tables
Table Page
1. X-Band Transmit Characteristics ..................................................................... 8
2. S- and X-Band Receive Characteristics .............................................................. 10
3. Gain Reduction Due to Wind Loading, 34-m HEF Antennas............................................... 13
4. System Noise Temperature Contributions due to 25% Weather........................................... 13
5. Recommended Minimum Operating Carrier Signal Levels (dBm) .......................................... 14
A-1 Vacuum Component of Gain Parameters................................................................ 23
A-2 S- and X-Band Zenith Atmosphere Attenuation Above Vacuum (A_ZEN)................................... 24
A-3 Vacuum Component of System Noise Temperature Parameters ........................................... 24
1 Introduction
1.1 Purpose
This module provides the performance parameters for the Deep Space Network
(DSN) high-efficiency (HEF) 34-meter antennas that are necessary to perform the nominal
design of a telecommunications link. It also summarizes the capabilities of these antennas for
mission planning purposes and for comparison with other ground station antennas.
1.2 Scope
The scope of this module is limited to providing those parameters that
characterize the RF performance of the 34-meter HEF antennas. The parameters do not include
effects of weather, such as reduction of system gain and increase in system noise temperature,
that are common to all antenna types. These are discussed in module 105, Atmospheric and
Environmental Effects. This module also does not discuss mechanical restrictions on antenna
performance that are covered in module 302, Antenna Positioning.
2 General Information
The DSN 34-m Antenna Subnet contains three 34-meter diameter HEF antennas.
These antennas employ an elevation over azimuth (AZ-EL) axis configuration, a single dualfrequency
feedhorn, and a dual-shaped reflector design. One antenna (DSS 15) is located at
Goldstone, California; one (DSS 45) near Canberra, Australia; and one (DSS 65) near Madrid,
Spain. The precise station locations are shown in Module 301, Coverage and Geometry.
A block diagram of the 34-meter HEF microwave and transmitter equipment is
shown in Figure 1. An orthomode junction for X-band is employed that permits simultaneous
right-circular polarization (RCP) or left-circular polarization (LCP) operation. For listen-only
operation or when transmitting and receiving on opposite polarizations, the low-noise path
(orthomode upper arm) is used for reception. If the spacecraft receives and transmits
simultaneously with the same polarization, the diplexed path must be used and the noise
temperature is higher. The labyrinth used to extract the S-band signal from the feed also provides
simultaneous RCP and LCP operation; however, the presence of only one S-band low noise
amplifier (LNA) and receiver channel limits the use to selectable RCP or LCP.
In addition to spacecraft tracking, the DSN 34-m Antenna Subnet is also used for
very-long baseline interferometry and radio-source catalog maintenance.
2.1 Telecommunications Parameters
The significant parameters of the 34-meter HEF antennas that influence
telecommunications link design are listed in Tables 1 and 2. Variations in these parameters that
are inherent in the design of the antennas are discussed below. Other factors that degrade link
performance are discussed in modules 105 (Atmospheric and Environmental Effects) and 106
(Solar Corona and Wind Effects).
2.1.1 Antenna Gain Variation
The antenna gains in Tables 1 and 2 do not include the effect of atmospheric
attenuation and should be regarded as vacuum gain at the specified reference point.
2.1.1.1 Frequency Effects
Antenna gains are specified at the indicated frequency (f0). For operation at higher
frequencies in the same band, the gain (dBi) must be increased by 20 log (f/f0). For operation at
lower frequencies in the same band, the gain must be reduced by 20 log (f/f0).
2.1.1.2 Elevation Angle Effects
Structural deformation causes a reduction in gain whenever the antenna is
operated at an elevation angle other than the angle where the reflector panels were aligned. The
effective gain of the antenna is reduced also by atmospheric attenuation, which is a function of
elevation. Figures 2 through 5 show the estimated gain versus elevation angle for the
hypothetical vacuum condition (structural deformation only) and with 0%, 50%, and 90%
weather conditions, designated as CD (cumulative distribution) = 0.00, 0.50, and 0.90. A CD of
0.00 (0%) means the minimum weather effect (exceeded 100% of the time). A CD of 90.0 (90%)
means that effect which is exceeded only 10% of the time. Qualitatively, a CD of 0.00
corresponds to the driest condition of the atmosphere; a CD of 0.50 corresponds to humid or very
light clouds; and 0.90 corresponds to very cloudy, but with no rain. A CD of 0.25 corresponds to
average clear weather and often is used when comparing gains of different antennas.
Comprehensive S-band and X-band weather-effects models (for weather conditions up to 99%
cumulative distribution) are provided in module 105 for detailed design control table use.
Equations and parameters for the curves in Figures 2 through 5 are provided in Appendix A.
2.1.1.3 Wind Loading
The gain reduction at X-band due to wind loading is listed in Table 3. The tabular
data are for structural deformation only and presume that the antenna is maintained on-point by
conical scan (CONSCAN, discussed in module 302) or an equivalent process. In addition to
structural deformation, wind introduces a pointing error that is related to the antenna elevation
angle, the angle between the antenna and the wind, and the wind speed. The effects of pointing
error are discussed below. Cumulative probability distributions of wind velocity at Goldstone are
given in module 105.
2.1.2 System Noise Temperature Variation
The operating system temperature (Top) varies as a function of elevation angle due
to changes in the path length through the atmosphere and ground noise received by the sidelobe
pattern of the antenna. Figures 6 through 10 show the combined effects of these factors in a
hypothetical vacuum (no atmosphere) condition and with the three weather conditions described
above. The equations and parameters for these curves are provided in Appendix A of this
module.
The system noise temperature values in Table 2 include a contribution due to 25%
weather that must be subtracted for comparison with antennas that are specified without
atmosphere (hypothetical vacuum). Table 4 provides adjustments to the 25% weather operating
system temperature that were calculated using the weather models in module 105.
When two low-noise amplifiers (LNAs) are available for use, the amplifier in the
lowest noise configuration is designated as LNA-1. Under some conditions, LNA-2 may be
used, and the higher noise temperature values apply.
2.1.3 Pointing Accuracy
Figures 11 and 12 show the effects of pointing error on effective transmit and
receive gain of the antenna. These curves are Gaussian approximations based on measured and
predicted antenna beamwidths. Data have been normalized to eliminate elevation and windloading
effects. The equations used to derive the curves are provided in Appendix A.
2.2 Recommended Minimum Operating Carrier Signal Levels
Table 5 provides the recommended minimum operating carrier-signal levels for
selected values of receiver tracking-loop bandwidth (Bl). These levels provide a signal-to-noise
ratio of 10 dB in the carrier-tracking loop, based on the nominal zenith system temperatures
given in Table 2 and assuming 25% weather.
3 Proposed Capabilities
The following paragraph discusses capabilities that have not yet been
implemented by the DSN but have adequate maturity to be considered for spacecraft mission and
equipment design. Telecommunications engineers are advised that any capabilities discussed in
this section cannot be committed to except by negotiation with the Telecommunications and
Mission Operations Directorate (TMOD) Plans and Commitments Program Office.
3.1 S-Band LNA Enhancement
The existing S-band high-electron-mobility transistor (HEMT) LNAs at DSS 15
and DSS 45 and the cooled field-effect transistor (FET) LNA at DSS 65 are in the process of
being replaced with HEMT amplifiers incorporating a cryogenically cooled input filter. The
result will be a reduction in S-band system temperature (Top) at all HEF stations to 26 +/-2 K near
zenith, assuming a 25% average clear atmosphere.
Table 1. X-Band Transmit Characteristics
Parameter Value Remarks
ANTENNA
Gain at 7145 MHz (dBi) 67.1 +/-0.2 At gain set elevation angle, referenced to
feedhorn aperture for matched
polarization; no atmosphere included
Transmitter Waveguide Loss (dB) 0.25 +/-0.05 20-kW transmitter output terminal
(waterload switch) to feedhorn aperture
Half-Power Beamwidth (deg) 0.0777 +/-0.004 Angular width (2-sided) between half-power
points at specified frequency
Polarization RCP or LCP One polarization at a time, remotely selected
Ellipticity (dB) 1.0 (max) Peak-to-peak axial ratio defined as the
ratio of peak-to-trough received voltages
with a rotating linearly polarized source
and the feed configured as a circularly
(elliptically) polarized receiving antenna
Pointing Loss (dB)
Angular See module 302 Also see Figure 12
CONSCAN 0.1 X-band CONSCAN reference set for 0.1 dB loss
EXCITER AND TRANSMITTER
RF Power Output (dBm) 73.0, +0.0, -1.0 Referenced to 20-kW transmitter output
terminal (waterload switch). Settability is
limited to 0.25 dB by measurement
equipment precision
Power output varies across the bandwidth and may be as much as 1 dB below nominal rating.
Performance will also vary from tube to tube. Normal procedure is to run the tubes saturated, but
unsaturated operation is also possible. The point at which saturation is achieved depends on drive
power and beam voltage. The 20-kW tubes are normally saturated for power levels greater than 60
dBm (1 kW). Minimum power out of the 20-kW tubes is about 53 dBm (200 W). Efficiency of the
tubes drops off rapidly below nominal rated output.
EIRP (dBm) 139.9, +0.2, -1.0
Frequency Range Covered (MHz) 7145 to 7190
Instantaneous 1-dB Bandwidth (MHz) 45
Coherent with Deep Space 7151.9-7177.3 240/749 turnaround ratio
S-Band D/L Allocation
Coherent with Deep 7151.9-7188.9 880/749 turnaround ratio
Space S-Band D/L
Allocation
Tunability (Hz) At transmitter output frequency
Phase Continuous Tuning Range 2.0 MHz
Maximum Tuning Rate +/-12.1 kHz/s
Frequency Error 0.012 Hz Average over 100 ms with respect to
frequency specified by predicts
Ramp Rate Error 0.001 Hz/s Average over 4.5 s with respect to rate
calculated from frequency predicts
Stability At transmitter output frequency
Output Power Variation (dB) Across frequency band over 12-h period
Saturated Drive 0.25
Unsaturated Drive <=1.0
Group Delay Stability (ns) <=1.0 Ranging modulation signal path over
12-h period (see module 203)
Frequency Stability Allan deviation
1 s 3.3 x 10^-13
10 s 5.2 x 10^-14
1000-3600s 3.1 x 10^-15
Spurious Output (dB) Below carrier
1-10Hz -50
10 Hz-1.5Mhz -60
1.5 MHz-8 MHz -45
2nd Harmonic -75
3rd, 4th & 5th Harmonics -60
Table 2. S- and X-Band Receive Characteristics
Parameter Value Remarks
ANTENNA
Gain (dBi) At gain set point (peak of gain versus
elevation curve). See Figures 2-5 for
elevation dependency. Tolerances have
triangular PDF.
S-Band (2295 MHz) 56.0 +/-0.25 Referenced to LNA input terminal (includes
feedline loss) for matched polarization, no
atmosphere included
X-Band (8420 MHz) 68.3 +/-0.2 Referenced to maser LNA input terminal
(includes feedline loss), non-diplexed (low
noise) path, for matched polarization, no
atmosphere included
68.1 +/-0.2 Referenced to maser LNA input terminal
(includes feedline loss), diplexed path, for
matched polarization, no atmosphere
included
68.2 +/-0.2 Referenced to wideband HEMT input
terminal (includes feedline loss), nondiplexed
path, for matched polarization, no
atmosphere included
68.0 +/-0.2 Referenced to wideband HEMT input
terminal (includes feedline loss), diplexed
path, for matched polarization, no
atmosphere included
Half-Power Beamwidth (deg.) Angular width (2-sided) between half-power
points at specified frequency
S-Band 0.242 +/-0.020
X-Band 0.0660 +/-0.004
Polarization Remotely selected
S-Band RCP or LCP
X-Band RCP or LCP Same or opposite from transmit
polarization
Ellipticity (dB) 0.7 Peak-to-peak voltage axial ratio,
RCP and LCP. See definition in Table 1.
S-Band <=1.0
X-Band <=0.8
Pointing Loss (dB, 3 sigma)
Angular See module 302 Also see Figures 11 and 12
CONSCAN
S-Band 0.03 Loss at S-band when using X-band
CONSCAN reference set for 0.1 dB loss at
X-band
0.1 Recommended value when using S-band
CONSCAN reference
X-Band 0.1 Recommended value when using X-band
CONSCAN reference
RECEIVER
Frequency Ranges Covered(MHz)
S-Band 2200-2300 MHz
X-Band
Telemetry 8400-8500 MHz
VLBI 8200-8600 MHz Wideband HEMT LNA
Recommended Maximum -90.0 At LNA input terminal
Signal Power (dBm)
Recommended Minimum See Table 5
Signal Power (dBm)
System Noise Temperature (K) For average clear weather (25% weather
condition) near zenith. See Figures 6-9 for
elevation dependency. See Table 4 for
adjustments to remove atmospheric
contribution.
S-Band (2200-2300 MHz) 38.1 (DSS 15, 45)
44.1 (DSS 65)
With respect to LNA input terminal.
X-Band (8400-8600 MHz)
DSS 15 19.8 +/-2 With respect to maser input terminal, nondiplexed path.
DSS 45 20.2 +/-2
DSS 65 20.1 +/-2
DSS 15 28.9 +/-2 With respect to maser input terminal, diplexed path.
DSS 45 29.3 +/-2
DSS 65 29.2 +/-2
DSS 15 44.8 +/-2 With respect to wideband HMT input terminal, diplexed path.
DSS 45 45.2 +/-2
DSS 65 45.1 +/-2
(8200-8600 MHz)
DSS 15 35.7 +/-2 With respect to wideband HMT input terminal, non-diplexed path.
DSS 45 36.1 +/-2
DSS 65 36.0 +/-2
Carrier Tracking Loop Noise 0.25-200 Effective one-sided, noise-equivalent carrier loop bandwidth (BL)
B/W (Hz)
Table 3. Gain Reduction Due to Wind Loading, 34-m HEF Antennas
Wind Speed X-Band Gain Reduction (dB)*
(km/hr) (mph)
16 10 0.2
48 30 0.3
72 45 0.4
* Assumes antenna is maintained on-point using CONSCAN or equivalent
closed-loop pointing technique.
S-band gain reduction is negligible for wind speeds up to 72 km/hr (45 mph).
Worst case, with most adverse wind orientation.
Table 4. System Noise Temperature Contributions due to 25% Weather
Location Noise Temperature Contribution (K)+
S-band X-band
Goldstone (DSS 15) 1.929 2.292
Canberra (DSS 45) 2.109 2.654
Madrid (DSS 65) 2.031 2.545
+ Calculated using weather model in module 105.
Table 5. Recommended Minimum Operating Carrier Signal Levels (dBm)*
Receiver Effective Noise Bandwidth (BL) (Hz)
Band, LNA, and Configuration Receiver Effective Noise Bandwidth (B_L) (Hz)
0.25 1.0 2.0 20.0 200
S-Band LNA
DSS 15 and DSS 45 (HEMT) -178.8 -172.8 -169.8 -159.8 -149.8
DSS 65 (Cooled FET) -178.2 -172.2 -169.1 -159.1 -149.1
X-Band Primary LNA (MASER)
DSS 15 Non-Diplexed -181.7 -175.6 -172.6 -162.6 -152.6
DSS 45 Non-Diplexed -181.6 -175.5 -172.5 -162.5 -152.5
DSS 65 Non-Diplexed -181.6 -175.6 -172.6 -162.6 -152.6
DSS 15 Diplexed -180.0 -174.0 -171.0 -161.0 -151.0
DSS 45 Diplexed -180.0 -173.9 -170.9 -160.9 -150.9
DSS 65 Diplexed -180.0 -173.9 -170.9 -160.9 -150.9
X-Band Backup LNA (W/B HEMT)
DSS 15 Non-Diplexed -179.1 -173.1 -170.1 -160.1 -150.1
DSS 45 Non-Diplexed -179.0 -173.0 -170.0 -160.0 -150.0
DSS 65 Non-Diplexed -179.1 -173.0 -170.0 -160.0 -150.0
DSS 15 Diplexed -178.1 -172.1 -169.1 -159.1 -149.1
DSS 45 Diplexed -178.1 -172.0 -169.0 -159.0 -149.0
DSS 65 Diplexed -178.1 -172.1 -169.0 -159.0 -149.0
* Levels are referenced to LNA input terminals with nominal zenith system noise
including 25% weather.
* Bandwidths are centered about the received carrier.
Figure 1. Functional Block Diagram of Microwave and Transmitter Subsystem
(Figure omitted in text-only document)
Figure 2. S-Band Receive Gain Versus Elevation Angle, All HEF Antennas
(Figure omitted in text-only document)
Figure 3. X-Band Receive Gain Versus Elevation Angle, DSS 15 Antenna,
(Figure omitted in text-only document)
Figure 4. X-Band Receive Gain Versus Elevation Angle, DSS 45 Antenna,
(Figure omitted in text-only document)
Figure 5. X-Band Receive Gain Versus Elevation Angle, DSS 65 Antenna,
(Figure omitted in text-only document)
Figure 6. S-Band System Temperature Versus Elevation Angle, Average
(Figure omitted in text-only document)
Figure 7. S-Band System Temperature Versus Elevation Angle, DSS 65
(Figure omitted in text-only document)
Figure 8. X-Band System Temperature Versus Elevation Angle, DSS 15
(Figure omitted in text-only document)
Figure 9. X-Band System Temperature Versus Elevation Angle, DSS 45
(Figure omitted in text-only document)
Figure 10. X-Band System Temperature Versus Elevation Angle, DSS 65
(Figure omitted in text-only document)
Figure 11. S-Band Gain Reduction Versus Angle Off Boresight
(Figure omitted in text-only document)
Figure 12. X-Band Gain Reduction Versus Angle Off Boresight
(Figure omitted in text-only document)
Appendix A
Equations for Modeling
A.1 Equation for Gain Versus Elevation Angle
The following equation can be used to generate S-band receive and X-band
transmit and receive gain versus elevation angle curves. Examples of these curves are depicted in
Figures 2-5. See paragraph 2.1.1.1 for frequency effect modeling and module 105 for
atmospheric attenuation at weather conditions other than 0%, 50%, and 90% cumulative
distribution.
G(theta) = G_0 - G_0(theta - gamma)^2 - A_Z/sin(theta), dBi (1)
where
theta = antenna elevation angle (deg.) 0 <= theta <= 90
G_0, G_1, gamma = parameters from Table A-1
A_ZEN = zenith atmospheric attenuation from Table A-2 or from Table 2 in module 105, dB.
A.2 Equation for System Temperature Versus Elevation Angle
The following equation can be used to generate S- and X-band system
temperature versus elevation angle curves. Examples of these curves are depicted in Figures
6-10. See module 105 for atmospheric attenuation at weather conditions other than 0%, 50%,
and 90% cumulative distribution.
T_op(theta) = T_1 + T_2*exp(-a/(90.001-theta)) + (255 + 25CD)(1 - 1/10^(A_ZEN/(10sin(theta)))), K (2)
where
theta = antenna elevation angle (deg.), 6 <= theta <= 90
T1, T2, a = parameters from Table A-3
CD = cumulative distribution used to select A_ZEN from A-2 or from Table 2 of module 105, 0 <= CD <= 0.99
A_ZEN = zenith atmospheric attenuation for selected CD from Table A-2 or from Table 2 in module 105, dB.
A.3 Equation for Gain Reduction Versus Pointing Error
The following equation can be used to generate gain-reduction versus pointing
error curves, examples of which are depicted in Figures 10 and 11.
delta G(theta) = 10log(exp(2.773theta^2/HPBW^2)), dB
where
theta = pointing error (deg.)
HPBW = half-power angular beamwidth in degrees (from Tables 1 or 2).
Table A-1. Vacuum Component of Gain Parameters
Configuration and Stations Parameters+
G_0*(Transmit) G_0*(Receive) G_1 gamma
S-band, All Stations (Figure 2) - 56.00 0.000006 42.0
X-band, All Stations (Figures 3-5) 67.1 68.27 0.00008 42.0
Notes:
+ G0 values are nominal at the frequency specified in Table 1 or Table 2. Other
parameters apply to all frequencies within the same band.
* Favorable tolerance = +0.5 dB, adverse tolerance = -0.5 dB, with a triangular PDF.
Table A-2. S- and X-Band Zenith Atmosphere Attenuation Above Vacuum (AZEN)
Weather Condition+ A_ZEN, dB*
S-Band X-band
DSS 15 DSS 45 DSS 65 DSS 15 DSS 45 DSS 65
Vacuum 0.000 0.000 0.000 0.000 0.000 0.000
CD = 0.00 0.033 0.036 0.034 0.037 0.040 0.038
CD = 0.50 0.032 0.035 0.033 0.040 0.048 0.045
CD = 0.90 0.031 0.034 0.033 0.047 0.059 0.053
Notes:
* From Table 2 in module 105
+ CD = cumulative distribution.
Table A-3. Vacuum Component of System Noise Temperature Parameters
Configuration and Stations Parameters
T_1* T_2 a
S-Band, DSS 15 and DSS 45 36.1 8.063 63.45
S-Band, DSS 65 42.1 8.063 63.45
X-Band, All Stations, Maser Non-diplexed 17.55 1742 573.6
X-Band, All Stations, Maser Diplexed 26.65 1742 573.6
X-Band, All Stations, W/B HEMT, Non-diplexed 33.4. 1742 573.6
X-Band, All Stations, W/B HEMT, Diplexed 42.3 1742 573.6
Note:
* Favorable tolerance = -2 K, adverse tolerance = +2 K, with a triangular PDF
810-005, Rev. E
DSMS Telecommunications Link
Design Handbook
104
34-m BWG Stations
Telecommunications Interfaces
Effective November 30, 2000
Document Owner: Approved by:
----------------------- -----------------------
S.D. Slobin Date A.J. Freiley Date
Antenna System Engineer Antenna Product Domain Service
System Development Engineer
Released by:
[Signature on file in TMOD Library]
----------------------------------
TMOD Document Release Date
Change Log
Rev Issue Date Affected Paragraphs Change Summary
Initial 1/15/2001 All All
Note to Readers
There are two sets of document histories in the 810-005 document, and these
histories are reflected in the header at the top of the page. First, the entire document is
periodically released as a revision when major changes affect a majority of the modules. For
example, this module is part of 810-005, Revision E. Second, the individual modules also
change, starting as an initial issue that has no revision letter. When a module is changed, a
change letter is appended to the module number on the second line of the header and a summary
of the changes is entered in the module's change log.
This module supersedes TCI-31 in 810-005, Rev. D.
Contents
Paragraph Page
1 Introduction ......................................................................................... 5
1.1 Purpose............................................................................................. 5
1.2 Scope .............................................................................................. 5
2 General Information .................................................................................. 5
2.1 Telecommunications Parameters....................................................................... 7
2.1.1 Antenna Gain Variation............................................................................ 7
2.1.1.1 Frequency Effects............................................................................... 7
2.1.1.2 Elevation Angle Effects ........................................................................ 7
2.1.1.3 Wind Loading.................................................................................... 7
2.1.2 System Noise Temperature Variation................................................................ 8
2.1.3 Antenna Pointing ................................................................................. 8
2.1.3.1 Pointing Accuracy............................................................................... 8
2.1.3.2 Pointing Loss................................................................................... 9
2.1.3.3 Ka-Band Aberration Correction .................................................................. 9
2.2 Recommended Minimum Operating Carrier Signal Levels................................................. 9
3 Proposed Capabilities................................................................................ 10
3.1 34-m BWG Ka-Band Implementation ................................................................... 10
3.1.1 X-Band Uplink Performance........................................................................ 10
3.1.2 X-Band Downlink Performance ..................................................................... 10
3.1.3 Ka-Band Downlink Performance .................................................................... 10
Appendix A, Equations for Modeling .................................................................... 44
A.1 Equations for Gain Versus Elevation Angle ......................................................... 44
A.2 Equations for System Temperature Versus Elevation Angle............................................ 44
A.3 Equation for Gain Reduction Versus Pointing Error ................................................. 45
A.4 Equation for Transmit Aberration Gain Reduction.................................................... 45
Illustrations
Figure Page
1. Functional Block Diagram of DSS 24 Antenna.......................................................... 31
2 Functional Block Diagram of DSS 25 Antenna........................................................... 32
3. Functional Block Diagram of DSS 26 Antenna.......................................................... 33
4 Functional Block Diagram of DSS 34 and DSS 54 Antennas .............................................. 34
5. Functional Block Diagram of DSS 27 Antenna.......................................................... 35
6. DSS 24 (Goldstone) S-Band Receive Gain Versus Elevation Angle, S/X Mode, 2295 MHz .................. 36
7. DSS 27 (Goldstone) S-Band Receive Gain Versus Elevation Angle, 2295 MHz............................. 36
8. DSS 34 (Canberra) X-Band Receive Gain Versus Elevation Angle, S/X Mode, 8420 MHz ................... 37
9. DSS 54 (Madrid) X-Band Receive Gain Versus Elevation Angle, X-Only
Mode (S/X Dichroic Retracted), 8420 MHz............................................................. 37
10. DSS 25 (Goldstone) X-Band Receive Gain Versus Elevation Angle, 8420 MHz............................ 38
11. DSS 25 (Goldstone) Ka-Band Receive Gain Versus Elevation Angle,
X/Ka Mode (X/Ka Dichroic In-Place), 32000 MHz....................................................... 38
12. DSS 24 (Goldstone) S-Band System Temperature Versus Elevation Angle,
S/X Mode, Non-Diplexed Path, 2295 MHz .............................................................. 39
13. DSS 27 (Goldstone) S-Band System Temperature Versus Elevation Angle, Diplexed Path, 2295 MHz....... 39
14. DSS 34 (Canberra) X-Band System Temperature Versus Elevation Angle,
S/X Mode, Diplexed Path, 8420 MHz .................................................................. 40
15. DSS 54 (Madrid) X-Band System Temperature Versus Elevation Angle,
X-Only Mode (S/X Dichroic Retracted), Non-Diplexed Path, 8420 MHz................................... 40
16. DSS 25 (Goldstone) X-Band System Temperature Versus Elevation Angle, Non-Diplexed Path, 8420 MHz... 41
17. DSS 25 (Goldstone) Ka-Band System Temperature Versus Elevation Angle,
X/Ka Mode (X/Ka Dichroic in Place), 32000 MHz....................................................... 41
18. S-Band Gain Reduction Versus Angle off Boresight................................................... 42
19. X-Band Gain Reduction Versus Angle off Boresight................................................... 42
20. Ka-Band Gain Reduction Versus Angle off Boresight ................................................. 43
21. Ka-Band Transmit Gain Reduction Due to Aberration Correction....................................... 43
Tables
Table Page
1. Capabilities of DSN BWG and HSB Antennas ........................................................... 11
2. S-Band Transmit Characteristics, DSS 24, 34, and 54................................................. 11
3. S-Band Transmit Characteristics, DSS 27 ............................................................ 14
4. X-Band Transmit Characteristics, DSS 25, 26, 34, and 54............................................. 15
5. Ka-Band Transmit Characteristics, DSS 25............................................................ 18
6. S- and X-Band Receive Characteristics, DSS 24, 34, and 54 .......................................... 20
7. X- and Ka-Band Receive Characteristics, DSS 25 and 26............................................... 23
8. S-Band Receive Characteristics, DSS 27.............................................................. 25
9. Gain Reduction Due to Wind Loading, 34-m BWG Antennas............................................... 27
10. System Noise Temperature Contributions due to 25% Weather.......................................... 27
11. Pointing Accuracy and Pointing Loss in Various Wind Conditions..................................... 28
12. Recommended Minimum Operating Carrier Signal Levels (dBm) for
BWG Antennas Using the Block V Receiver (BVR) ..................................................... 29
13. Recommended Minimum Operating Carrier Signal Levels (dBm) for
BWG Antennas Using the Block V Receiver (BVR) ..................................................... 30
14. Recommended Minimum Operating Carrier Signal Levels (dBm) for
DSS 27 HSB Antenna Using the Multifunction Receiver (MFR) ......................................... 30
A-1. S-Band Vacuum Gain and System Noise Temperature Parameters ....................................... 46
A-2. X-Band Vacuum Gain and System Noise Temperature Parameters........................................ 47
A-3. Ka-Band Vacuum Gain and System Noise Temperature Parameters ...................................... 49
A-4. S-, X-, and Ka-Band Zenith Atmospheric Attenuation (AZEN) ........................................ 49
1 Introduction
1.1 Purpose
This module provides the performance parameters for the Deep Space Network
(DSN) 34-m Beam Waveguide (BWG) antennas and the 34-m High-Speed BWG (HSB) antenna
that are necessary to perform the nominal design of a telecommunications link. It also
summarizes the capabilities of these antennas for mission planning purposes and for comparison
with other ground station antennas.
1.2 Scope
The scope of this module is limited to providing those parameters that
characterize the RF performance of the 34-meter BWG and HSB antennas, including the effects
of weather that are unique to these types of antennas. Unless otherwise specified, the parameters
do not include weather effects, such as reduction of system gain and increase in system noise
temperature, that are common to all antenna types. These are discussed in module 105,
Atmospheric and Environmental Effects. This module also does not discuss mechanical
restrictions on antenna performance that are covered in module 302, Antenna Positioning.
2 General Information
The 34-meter diameter BWG and HSB antennas are the new generation of
antennas being built for use in the DSN. These antennas differ from more conventional antennas
(for example, the 34-meter HEF antennas; refer to module 103) in the fact that a series of small
mirrors (approximately 2.5 meters diameter) direct microwave energy from the region above the
main reflector to a location at the base of the antenna, typically in a pedestal room, which may be
located below ground level. The pedestal room is located below the azimuth track of the
antenna, although other beam-waveguide designs (not utilized by the DSN) locate the microwave
equipment in an "alidade room" above the azimuth track, but below the main reflector. All
antennas described in this module are of the pedestal room design.
In this configuration, numerous "stations" of microwave equipment, contained in
the pedestal room, can be accessed by rotation of an ellipsoidal mirror located on the pedestal
room floor. This enables great versatility of design and allows tracking using equipment at one
station while equipment installation or maintenance is carried out at the other stations. Since
cryogenic low-noise amplifiers (LNAs) do not tip (as they do when located in a cone or room
above the elevation axis), certain state-of-the-art ultra-low-noise amplifier (ULNA) and feed
designs can be implemented.
The HSB antenna differs from the BWG antennas in that the pedestal room is
above ground level, the optics design is different, and the subreflector does not focus
automatically for the purpose of maintaining gain as the elevation angle of the antenna changes.
The HSB antenna has higher tracking rates than do the BWG antennas; thus, it is the appropriate
antenna to use when tracking Earth-orbiting satellites.
The capabilities of each antenna are significantly different depending on the
microwave, transmitting, and receiving equipment installed. A summary of these differences is
provided in Table 1. Functional block diagrams for each antenna are provided in Figures 1-5. In
general, each antenna has two LNAs for telemetry reception or radio science (although the HSB
antenna only has one and DSS 25 has three). Each antenna also has at least one transmitter.
Antennas with more than one transmitter can operate only one of them at a time. Once again,
DSS 25 is an exception and has a Ka-band transmitter that can be operated at the same time as its
X-band transmitter.
All feeds provide selectable right-circular polarization (RCP) or left-circular
polarization (LCP) with the exception of the Ka-band feeds at DSS 25 that operate only with
RCP. The transmitter is coupled into the microwave path using a frequency-selective diplexer.
Because the diplexer increases the operating system temperature, a non-diplexed path is also
provided at all antennas (except the HSB antenna) for receive-only operation.
Stations with X-band transmitters can transmit with either the same or the
opposite polarization from that being received, whereas S-band transmission must be the same
polarization as is being received. If the uplink and downlink are of the same polarization,
reception must be through the diplexer with increased noise and lower gain than the nondiplexed
path. DSS 25 and DSS 26 have two X-band LNAs and can receive simultaneous RCP
and LCP (although one of the signals will be via the non-diplexed path and the other will be via
the diplexed path). The two LNAs at DSS 25 and DSS 26 can also be interchanged between the
diplexed and non-diplexed paths. Thus, there are four possible ways a single X-band signal can
be received at these stations.
2.1 Telecommunications Parameters
The significant parameters of the 34-meter BWG and HSB antennas that
influence the design of the telecommunications uplink are listed in Tables 2 through 8.
Variations in these parameters, which are inherent in the design of the antennas, are discussed
below. Other factors that degrade link performance are discussed in modules 105 (Atmospheric
and Environmental Effects) and 106 (Solar Corona and Solar Wind Effects).
The values in these tables do not include the effects of the atmosphere. However,
the attenuation and noise-temperature effects of weather for three specific weather conditions are
included in the figures at the end of the module so that they may be used for a quick estimate of
telecommunications link performance for those specific conditions without reference to module
105. For detailed design control table use, the more comprehensive and detailed S-, X-, and Kaband
weather effects models (for weather conditions up to 99% cumulative distribution) in
module 105 should be used.
2.1.1 Antenna Gain Variation
Because the gain is referenced to the feedhorn aperture, such items as diplexers
and waveguide runs to alternate LNAs that are "downstream" (below or toward the LNA) do not
affect the gain at the reference plane. Dichroic plates that are "upstream" of the feedhorn
aperture cause a reduction in gain.
2.1.1.1 Frequency Effects
Antenna gains are specified at the indicated frequency (f0). For operation at higher
frequencies in the same band, the gain (dBi) must be increased by 20 log (f/f_0). For operation at
lower frequencies in the same band, the gain must be reduced by 20 log (f/f_0).
2.1.1.2 Elevation Angle Effects
Structural deformation causes a reduction in gain when the antenna is operated at
an elevation angle other than where the reflector panels were aligned. The effective gain of the
antenna also is reduced by atmospheric attenuation, which is a function of elevation. Figures 6
through 11 show representative curves of gain versus elevation angle for selected stations and
configurations. The curves show the hypothetical vacuum (no atmosphere) condition and the
gain with 0%, 50%, and 90% weather conditions, designated as CD (cumulative distribution) =
0.00, 0.50, and 0.90. 0% means minimum weather effect (exceeded 100% of the time); 90%
means that effect which is exceeded only 10% of the time. Qualitatively, 0% corresponds to the
driest condition of the atmosphere; 25% corresponds to average clear; 50% corresponds to humid
or very light clouds; and 90% corresponds to very cloudy, but with no rain. Appendix A
provides the complete set of parameters from which these curves were created. These
parameters, in combination with the weather-effects parameters from module 105, can be used to
calculate the gain versus elevation angle curve for any antenna, in any configuration, for weather
conditions up to 99% CD.
2.1.1.3 Wind Loading
The gain reduction at X-band due to wind loading is listed in Table 9. The tabular
data are for structural deformation only and presume that the antenna is maintained on-point by
conical scan (CONSCAN) or Monopulse, discussed in module 302, Antenna Positioning. In
addition to structural deformation, wind introduces a pointing error, which is related to the
antenna elevation angle, the angle between the antenna and the wind, and the wind speed. The
effects of pointing error are discussed below. Cumulative probability distributions of wind
velocity at Goldstone are given in module 105.
2.1.2 System Noise Temperature Variation
The operating system temperature (Top) varies as a function of elevation angle
due to changes in the path length through the atmosphere and ground noise received by the
sidelobe pattern of the antenna. Figures 12 through 17 show the combined effects of these
factors for the same set of stations and configurations selected above. The figures show the
hypothetical vacuum and the 0%, 50%, and 90% weather conditions. The equations and
parameters for these curves are provided in Appendix A and can be used, in combination with
the weather-effects parameters from module 105, to calculate the system temperature versus
elevation curve for any antenna, in any configuration, for weather conditions up to 99% CD.
When two LNAs are available for use, the amplifier in the lowest loss (lowest
noise) configuration is considered prime and is designated LNA-1. Under some conditions,
LNA-2 may be used; in these instances, the higher noise-temperature values apply.
The system temperature values in Tables 6-8 do not include any atmospheric
contribution and must be increased for comparison with antennas that are specified with 25%
weather. Table 10 provides adjustments to the hypothetical no-atmosphere (vacuum) operating
system temperature (Top, vac) that were calculated using the weather models in module 105.
2.1.3 Antenna Pointing
2.1.3.1 Pointing Accuracy
The pointing accuracy of an antenna, often referred to as its blind-pointing
performance, is the difference between the calculated beam direction and the actual beam
direction. The error is random and can be divided into two major categories. The first of these
includes the computational errors and uncertainties associated with the radio sources used to
calibrate the antenna and the location of the spacecraft provided by its navigation team. The
second has many components associated with converting a calculated beam direction to the
physical positioning of a large mechanical structure. Included are such things as atmospheric
instability, servo and encoder errors, thermally and gravitationally induced structural
deformation, azimuth track leveling (for an azimuth-elevation antenna), and both seismic and
diurnal ground tilt.
Blind pointing is modeled by assuming equal pointing performance in the
elevation (EL) and cross-elevation (X-EL) directions. That is, the random pointing errors in each
direction have uncorrelated Gaussian distributions with the same standard deviation. This results
in a Rayleigh distribution for pointing error where the mean radial error is 1.253 times the
standard deviation of the EL and X-EL components. For a Rayleigh distribution, the probability
that the pointing error will be less than the mean radial error is 54.4%. Conversely, the
probability that the mean radial error will be exceeded is 45.6%.
Table 11 provides the modeled blind-pointing performance and the resulting gain
reductions in various wind conditions for the BWG antennas. In addition to the mean radial
error (CD = 54.4%), pointing errors for the 90%, 95%, and 99% points on the Rayleigh
distribution curve are also provided. A CD of 90% implies that 90% of the time, the pointing
error or pointing loss will be less than the value shown, and so forth.
2.1.3.2 Pointing Loss
Figures 18 through 20 show the effects of pointing error on effective transmit and
receive gain of the antenna. These curves are Gaussian approximations based on measured and
predicted antenna beamwidths. Data have been normalized to eliminate elevation and windloading
effects. The equations used to derive the curves are provided in Appendix A.
2.1.3.3 Ka-Band Aberration Correction
The extremely narrow beamwidth at Ka-band requires that a Ka-band uplink
signal be aimed at where the spacecraft will be when the signal arrives, while simultaneously
receiving a signal that left the spacecraft one light-time previously. This is accomplished by
mounting the Ka-band transmit feed on a movable X-Y platform that can displace the transmitted
beam as much as 30 millidegrees from the received beam. The fact that the transmit feed is
displaced from its optimum focus causes the gain reduction depicted in Figure 21. The equation
used to generate this curve is provided in Appendix A.
2.2 Recommended Minimum Operating Carrier Signal Levels
Table 12 provides the recommended minimum operating carrier-signal levels for
selected values of receiver tracking-loop bandwidth (Bl) when using the Block V Receiver
(BVR). These levels provide a signal-to-noise ratio of 10 dB in the carrier tracking loop, based
on the nominal zenith system temperatures given in Tables 5-8 adjusted for an average clear
atmosphere, CD=0.25. Use of loop bandwidths less than 1 Hz are not recommended for the HSB
antenna due to phase noise introduced by its long distance (approximately 30 km) between the
antenna and its BVR.
The HSB antenna has an additional receiver, the Multifunction Receiver (MFR),
that provides wider loop bandwidths for high-Doppler Earth-orbiter spacecraft. The
recommended minimum operating carrier signal levels for the available MFR tracking loop
bandwidths are provided in Table 13. These values also provide a tracking loop signal-to-noise
ratio of 10 dB based on the nominal zenith system temperature given in Table 8 and an average
clear atmosphere.
3 Proposed Capabilities
The following paragraphs discuss capabilities that have not yet been implemented
by the DSN but have adequate maturity to be considered for spacecraft mission and equipment
design. Telecommunications engineers are advised that any capabilities discussed in this section
cannot be committed to except by negotiation with the Telecommunications and Mission
Operations Directorate (TMOD) Plans and Commitments Program Office.
3.1 34-m BWG Ka-Band Implementation
All DSN BWG antennas except DSS 27 are being equipped with a Ka-band
receive-only capability by replacing the existing X-band feed and microwave components with
an X/X/Ka-band feed that includes the X-band diplexing function. The 34-m BWG Ka-band
implementation will eliminate the need to run transmitted power through the feed's receive port
and allows the entire receive portion to be cryogenically cooled.
3.1.1 X-Band Uplink Performance
The X-band uplink performance will be as described in Table 4 (with the
exception of X-band effective isotropic radiated power [EIRP] that may be reduced
approximately 0.1 dB due to increased loss in the waveguide that couples the transmitter to the
feed). An X-band transmitter will be added to DSS 24 so that all BWG antennas (except DSS
27) will have X-band uplink and simultaneous X- and Ka-band downlink capability.
3.1.2 X-Band Downlink Performance
The combination of the cryogenically cooled feed, better amplifiers, and reduced
microwave complexity is expected to provide a peak vacuum gain over temperature (G/T) of 56
dB at all stations. This G/T will be independent of whether the transmitter is in operation and
will apply when the polarization is the same as the transmitter or opposite to the transmitter.
Uplink and downlink polarization will be independent, and DSS 25 and 26 will be able to
provide simultaneous RCP and LCP because they have two X-band downconverters. The
remaining stations will provide selectable RCP or LCP. Other receive characteristics will be as
described in Tables 6 and 7.
3.1.3 Ka-Band Downlink Performance
The same technology used at X-band is expected to provide a peak vacuum
Ka-band G/T of at least 63.6 dB at all stations. Selectable RCP or LCP will be available,
however monopulse tracking will only be available for RCP. Other receive characteristics will
be as described in Table 7.
Table 1. Capabilities of DSN BWG and HSB Antennas
S-band X-band Ka-band
Antenna Type S-band X-band Ka-band
Uplink* Downlink+ Uplink* Downlink+ Uplink* Downlink+
DSS 24 BWG 20 kW 1 - 1 - -
DSS 25 BWG - - 4 kW 1 800 W 1
DSS 25 BWG - - 4 kW 2 - -
DSS 27 HSB 200 W 1 - - - -
DSS 34 BWG 20 kW 1 4 kW 1 - -
DSS 54 BWG 20 kW 1 4 kW 1 - -
Notes:
* An entry in this column refers to the maximum available uplink power. A dash means that no
capability is available.
+ An entry in this column refers to the maximum number of Low Noise Amplifiers and receiver frontends
that are available for this band. A dash mean that no capability is available.
Table 2. S-Band Transmit Characteristics, DSS 24, 34, and 54
Parameter Value Remarks
ANTENNA
Gain at 2115 MHz (dBi) 56.1, +0.2, -0.3 dB At peak of gain versus elevation curve,
referenced to feedhorn aperture for
matched polarization; no atmosphere
included; triangular probability density
function (PDF) tolerance.
Transmitter Waveguide Loss (dB) 0.6 +/-0.1 20-kW transmitter output terminal
(waterload switch) to feedhorn aperture
Half-Power Beamwidth (deg) 0.263 +/-0.020 Angular width (2-sided) between half-power
points at specified frequency
Polarization RCP or LCP One polarization at a time, remotely
selected. Polarization must be the same as
received polarization.
Ellipticity (dB) 1.0 (max) Peak-to-peak axial ratio defined as the
ratio of peak-to-trough received voltages
with a rotating linearly polarized source
and the feed configured as a circularly
(elliptically) polarized receiving antenna
Pointing Loss (dB)
Angular See module 302 Also see Figure 18
CONSCAN 0.01 X-band CONSCAN reference set for 0.1
dB loss
0.1 S-band CONSCAN reference set for 0.1
dB loss
EXCITER AND TRANSMITTER
Frequency Range Covered (MHz) 2025-2120 Power amplifier is step-tunable over the
specified range in six 20-MHz segments,
with 5-MHz overlap between segments.
Tuning between segments can be
accomplished in 30 seconds.
Instantaneous 1-dB Bandwidth 20
(MHz)
Coherent with Earth Orbiter 2028.8-2108.7 240/221 turnaround ratio
S-Band D/L Allocation
Coherent with deep space 2110.2-2117.7 240/221 turnaround ratio
S-Band D/L channels
Coherent with deep space 2110.2-2119.8 880/221 turnaround ratio
X-Band D/L channels
RF Power Output (dBm) Referenced to 20-kW transmitter output
terminal (waterload switch). Settability is
limited to 0.25 dB by measurement
equipment precision.
2025-2070 MHz 53.0-73.0, +0.0, -1.0
2070-2090 MHz 53.0-67.0, +0.0, -1.0 S-band uplink is restricted to 5 kW over
2070-2090 frequency range
2060-2120 MHz 53.0-73.0, +0.0, -1.0
Power output varies across the bandwidth and may be as much as 1 dB below nominal rating.
Performance will also vary from tube to tube. Normal procedure is to run the tubes saturated, but
unsaturated operation is also possible. The point at which saturation is achieved depends on drive
power and beam voltage. The 20-kW tubes are normally saturated for power levels greater than 60
dBm (1 kW). Minimum power out of the 20-kW tubes is about 53 dBm (200 W). Efficiency of the
tubes drops off rapidly below nominal rated output.
EIRP (dBm) 128.5, +0.2, -1.0 dB At gain set elevation angle, referenced to
feedhorn aperture
Tunability At transmitter output frequency
Phase Continuous 2.0
Tuning Range (MHz)
Maximum Tuning Rate (kHz/s) +/-12.1
Frequency Error (Hz) 0.012 Average over 100 ms with respect to
frequency specified by predicts
Ramp Rate Error (Hz/s) 0.001 Average over 4.5 s with respect to rate
calculated from frequency predicts
Stability At transmitter output frequency
Output Power Stability (dB) Over 12-h period
Saturated Drive 0.5
Unsaturated Drive 1.0
Incidental AM (dB) 60 Below carrier
Group Delay Stability (ns) <=3.3 Ranging modulation signal path
(see module 203) over 12-h period
Frequency Stability Allan deviation
1000 s 5.0 x 10^-14
Spurious Output (dB) Below carrier
2nd Harmonic -85
3rd Harmonic -85
4th Harmonic -140 At input to X-band horn, with transmitter
set for 20-kW output
Table 3. S-Band Transmit Characteristics, DSS 27
Parameter Value Remarks
ANTENNA
Gain at 2115 MHz (dBi) 54.4, +0.2, -0.3 dB At peak of gain versus elevation angle
curve, referenced to feedhorn aperture for
matched polarization; no atmosphere
included; triangular PDF tolerance.
Transmitter Waveguide Loss (dB) 0.6 +/-0.1 20-kW transmitter output terminal
(waterload switch) to feedhorn aperture
Half-Power Beamwidth (deg) 0.263 +/-0.020 Angular width (2-sided) between halfpower
points at specified frequency
Polarization RCP or LCP One polarization at a time, remotely
selected. Polarization must be the same as
received polarization.
Ellipticity (dB) 1.0 (max) Peak-to-peak axial ratio defined as the
ratio of peak-to-trough received voltages
with a rotating linearly polarized source
and the feed configured as a circularly
(elliptically) polarized receiving antenna
Pointing Loss
Angular See module 302 Also see Figure 18
EXCITER AND TRANSMITTER
Frequency range covered (MHz) 2025-2120
Coherent with Earth orbiter 2028.8-2108.7 240/221 turnaround ratio
S-Band D/L allocation
Coherent with deep space 2110.2-2117.7 240/221 turnaround ratio
S-Band D/L channels
Coherent with deep space 2110.2-2119.8 880/221 turnaround ratio. No X-band
X-Band D/L channels receiver is available at DSS 27
RF Power Output (dBm) 47.0-53.0, +/-0.5 dB Referenced to 200 W transmitter output
terminal (power load switch). Settability is
limited to 0.25 dB by measurement
equipment precision.
Power output varies across the bandwidth and may be as much as 1 dB below nominal rating. The
200 W tube is a fixed beam klystron designed to saturate at its rated power. Operation at less than
the nominal 200 W is accomplished by operating the tube unsaturated. Minimum power out of is
about 47 dBm (50 W).
EIRP (dBm) 106.8 +/-0.6 dB At gain set elevation angle, referenced to
feedhorn aperture
Tunability (Hz) 100 At transmitter output frequency
Output Power Stability (dB) +/-0.25 Worst case over 8-h period using 30-m
sample intervals
Spurious Output (dB) Below carrier
2025-2120 MHz -88
2200-2300 MHz -94
2nd Harmonic -60
3rd Harmonic -60
8400-8500 MHz -94
Table 4. X-Band Transmit Characteristics, DSS 25, 26, 34, and 54
Parameter Value Remarks
ANTENNA
Gain at 7145 MHz (dBi) 67.1, +0.2, -0.3 dB At peak of gain versus elevation angle
curve, referenced to feedhorn aperture for
matched polarization; no atmosphere
included; triangular PDF tolerance.
Transmitter Waveguide Loss (dB) 0.4 +/-0.1 4-kW transmitter output terminal
(waterload switch) to feedhorn aperture
Half-Power Beamwidth (deg) 0.0777 +/-0.0040 Angular width (2-sided) between halfpower
points at specified frequency
Polarization RCP or LCP One polarization at a time, remotely
selected, independent of received
polarization.
Ellipticity (dB) 1.0 (max) Peak-to-peak axial. See Table 2 for definition.
Pointing Loss (dB)
Angular See module 302 Also see Figure 19
CONSCAN 0.1 X-band CONSCAN reference set for 0.1 dB loss
EXCITER AND TRANSMITTER
Frequency range covered (MHz) 7145-7190
Coherent with deep space S-Band 7147.3-7177.3 240/749 turnaround ratio
D/L channels
Coherent with deep space X-Band 7149.6-7188.9 880/749 turnaround ratio
D/L channels
RF Power Output (dBm) 47.0-66.0, +/-0.5 dB Referenced to 4-kW transmitter output
terminal (waterload switch). Settability is
limited to 0.25 dB by measurement
equipment precision.
Power output varies across the bandwidth and may be as much as 1 dB below nominal rating. The 4
kW tubes are fixed beam klystrons designed to saturate at their rated power however performance
varies from tube to tube. Operation at less than the nominal 4.0 kW is unsaturated. Minimum power
output is about 47 dBm (50 W). Efficiency of the tubes drops off rapidly below nominal rated output.
EIRP (dBm) 133.1 +/-0.7 dB At gain set elevation angle, referenced to
feedhorn aperture
Tunability At transmitter output frequency
Phase Continuous Tuning Range 2.0 MHz
(MHz)
Maximum Tuning Rate (kHz/s) +/-12.1
Frequency Error (Hz) 0.012 Average over 100 ms with respect to
frequency specified by predicts
Ramp Rate Error (Hz/s) 0.001 Average over 4.5 s with respect to rate
calculated from frequency predicts
Stability At transmitter output frequency
Output Power Stability (dB) 0.2 First Differences, 10-1000 s intervals over
12-h period
Output Power Variation (dB) Across frequency band over 12-h period
Saturated Drive 0.25
Unsaturated Drive 1.0
Group Delay Stability (ns) <=1.0 Ranging modulation signal path over 12-h
period (see module 203)
Frequency Stability Allan deviation
1 s 3.3 x 10^-13
10 s 5.0 x 10^-14
1000-3600 s 2.7 x 10^-15
Spurious Output (dB) Below carrier
1-10 Hz -50
10 Hz-1.5 MHz -60
1.5 MHz-8 MHz -45
2nd Harmonic -75
3rd, 4th & 5th Harmonics -60
Table 5. Ka-Band Transmit Characteristics, DSS 25
Parameter Value Remarks
ANTENNA
Gain at 34200 MHz (dBi) 79.5, +0.2, -0.3 dB At peak of gain versus elevation angle
curve, referenced to feedhorn aperture for
matched polarization; no atmosphere
included; triangular PDF tolerance.
Transmitter Waveguide Loss (dB) 0.25 +/-0.1 800W transmitter output terminal
(waterload switch) to feedhorn aperture
Half-Power Beamwidth (deg) 0.0162 +/-0.0010 Angular width (2-sided) between halfpower
points at specified frequency
Polarization RCP
Ellipticity (dB) 1.0 (max) Peak-to-peak axial. See Table 2 for
definition.
Pointing Loss CONSCAN is not available.
Angular See module 302 Also see Figure 20
EXCITER AND TRANSMITTER
Frequency range covered (MHz) 34200-34700
Coherent with deep space 34343.2-34570.9 3344/3599 turnaround ratio
Ka-Band D/L channels
Coherent with deep space 34354.3-34554.2 880/3599 turnaround ratio
X-Band D/L channels
RF Power Output (dBm) 47.0-59.0, +/-0.5 dB Referenced to 800 W transmitter output
terminal (waterload switch). Settability is
limited to 0.25 dB by measurement
equipment precision.
Power output varies across the bandwidth and may be as much as 1 dB below nominal rating. The
800 W tube is a fixed beam klystron designed to saturate at its rated power. Operation at less than
the nominal 800 W is unsaturated. Minimum power output is about 47 dBm (50 W).
EIRP (dBm) 138.2, +0.6, -0.5 dB At gain set elevation angle, referenced to
feedhorn aperture
Stability At transmitter output frequency
Output Power Variation (dB) Across frequency band over 12 h
Coherent with deep space 34354.3-34554.2 880/3599 turnaround ratio
RF Power Output (dBm) 47.0-59.0, +/-0.5 dB Referenced to 800 W transmitter output
terminal (waterload switch). Settability is
limited to 0.25 dB by measurement
equipment precision.
Power output varies across the bandwidth and may be as much as 1 dB below nominal rating. The
800 W tube is a fixed beam klystron designed to saturate at its rated power. Operation at less than
the nominal 800 W is unsaturated. Minimum power output is about 47 dBm (50 W).
EIRP (dBm) 138.2, +0.6, -0.5 dB Referenced to feed
Stability At transmitter output frequency
Output Power Variation (dB) Across frequency band over 12 h
Saturated Drive 0.25
Unsaturated Drive <=1.0
Frequency Stability Allan deviation
1 s 3.3 x 10^-13
10 s 5.2 x 10-14
1000-3600 s 3.1 x 10-15
1000-3600 s 3.1 x 10-15
Spurious Output (dB) Below carrier
1-10 Hz -50
10 Hz-1.5 MHz -60
1.5 MHz-8 MHz -45
Table 6. S- and X-Band Receive Characteristics, DSS 24, 34, and 54
Parameter Value Remarks
ANTENNA
Gain (dBi) At peak of gain versus elevation angle
curve, referenced to feedhorn aperture
(feed and feedline losses are accounted
for in system temperature), for matched
polarization; no atmosphere included;
triangular PDF tolerance. See Figures 6, 8,
and 9 for representative gain versus
elevation curves.
S-Band (2295 MHz) 56.8, +0.1, -0.2 dB
X-Band (8420 MHz) 68.2, +0.1, -0.2 dB
Half-Power Beamwidth (deg.) Angular width (2-sided) between halfpower
points at specified frequency
S-Band 0.242 +/-0.020
X-Band 0.0660 +/-0.0040
Polarization Remotely selected
S-Band RCP or LCP Same as transmit polarization
X-Band RCP or LCP Same as or opposite from transmit polarization
Ellipticity (dB) Peak-to-peak voltage axial ratio,
RCP and LCP. See definition in Table 2.
S-Band <=1.0
X-Band <=0.7
Pointing Loss (dB, 3 sigma)
Angular See module 302 Also see Figures 18 and 19
CONSCAN
S-Band 0.03 Loss at S-band when using X-band
CONSCAN reference set for 0.1 dB loss at
X-band
0.1 Recommended value when using S-band
CONSCAN reference
X-Band 0.1 Recommended value when using X-band
CONSCAN reference
RECEIVER
Frequency Ranges Covered (MHz)
S-Band 2200-2300
X-Band 8400-8500
Recommended Maximum -90 At LNA input terminal
Signal Power (dBm)
Recommended Minimum See Table 12
Signal Power (dBm)
System Noise Temperature (K) Near zenith, no atmosphere included.
See Figures 12, 14, and 15 for
representative system temperature versus
elevation curves. Tolerances have a
triangular PDF.
S-Band (2200-2300 MHz) Referenced to feedhorn aperture.
Non-Diplexed Path
DSS 24 28.3, -1.0, +2.0 K
DSS 34 30.7, -1.0, +2.0 K
DSS 54 28.9, -1.0, +2.0 K
S-Band (2200-2300 MHz) Referenced to feedhorn aperture.
Diplexed Path
DSS 24 34.8, -1.0, +2.0 K
DSS 34 39.3, -1.0, +2.0 K
DSS 54 37.5, -1.0, +2.0 K
X-Band (8400-8500 MHz) X-band only operation (S/X-band dichroic
Non-Diplexed Path plate retracted). Referenced to feedhorn
aperture.
DSS 24 23.2, -1.0, +2.0 K LNA = MASER
DSS 34 28.0, -1.0, +2.0 K LNA = HEMT
DSS 54 21.1, -1.0, +2.0 K LNA = MASER
X-Band (8400-8500 MHz) X-band only operation (dichroic plate
Diplexed Path retracted). Referenced to feedhorn aperture.
DSS 34 35.5, -1.0, +2.0 K LNA = HEMT
DSS 54 28.6, -1.0, +2.0 K LNA = MASER
X-Band
(8400-8500 MHz)
Non-Diplexed Path
S/X-band operation. Referenced to
feedhorn aperture.
DSS 24 24.6, -1.0, +2.0 K LNA = MASER
DSS 34 29.7, -1.0, +2.0 K LNA = HEMT
DSS 54 22.8, -1.0, +2.0 K LNA = MASER
X-Band S/X-band operation. Referenced to
(8400-8500 MHz) feedhorn aperture.
Diplexed Path
DSS 34 37.2, -1.0, +2.0 K LNA = HEMT
DSS 54 30.2, -1.0, +2.0 K LNA = MASER
Carrier Tracking Loop Noise 0.25-200 Effective one-sided, noise-equivalent
B/W (Hz) carrier loop bandwidth (BL)
Table 7. X- and Ka-Band Receive Characteristics, DSS 25 and 26
Parameter Value Remarks
ANTENNA
Gain (dBi) At peak of gain versus elevation angle
curve, referenced to feedhorn aperture
(feed and feedline losses are accounted for
in system temperature), for matched polarization;
no atmosphere included; triangular
PDF tolerance. See Figures 10 and 11 for
representative DSS 25 gain versus
elevation curves.
X-Band (8420 MHz) 68.4, +0.1, -0.2 dB DSS 25
68.3, +0.1, -0.2 dB DSS 26
Ka-Band (32000 MHz) DSS 25 only
79.0, +0.3, -0.3 dB Ka-band only operation (X-Ka dichroic
plate retracted).
78.8, +0.2, -0.3 dB X/Ka-band operation
Half-Power Beamwidth (deg.) Angular width (2-sided) between halfpower
points at specified frequency
X-Band 0.0660 +/-0.0040
Ka-Band 0.0174 +/-0.0020 DSS 25 only
Polarization
X-Band DSS 25 RCP and LCP Both polarizations simultaneously
available; polarization using diplexed path
is remotely selected
X-Band DSS 26 RCP or LCP One polarization at a time
Ka-Band RCP DSS 25 only
Ellipticity (dB) Peak-to-peak voltage axial ratio.
See definition in Table 2.
X-Band <=0.7 RCP and LCP
Ka-Band <=1.0
Pointing Loss (dB, 3 sigma)
Angular See module 302 Also see Figures 19 and 20
CONSCAN (Not available at Ka-band)
X-Band 0.1 Recommended value when using X-band
CONSCAN reference
Monopulse DSS 25 only. Receiver loop SNR >=35 dB
X-Band 0.007 Using Ka-band monopulse reference
Ka-Band 0.1
RECEIVER
Frequency Ranges (MHz)
X-Band 8400-8500
Ka-Band 31800-32300
Recommended Maximum -90.0 At LNA input terminal
Signal Power (dBm)
Recommended Minimum See Table 12
Signal Power (dBm)
System Noise Temperature (K) Near zenith, no atmosphere included. See
Figures 16 and 17 for DSS 25 system
temperature versus elevation curves.
Tolerances have a triangular PDF.
X-Band (8400-8500 MHz) Referenced to feedhorn aperture.
Non-Diplexed Path
DSS 25, LNA 1 22.1, -1.0, +2.0 K LNA = MASER
DSS 25, LNA 2 35.9, -1.0, +2.0 K LNA = HEMT
DSS 26 N/A
X-Band (8400-8500 MHz) Referenced to feedhorn aperture.
Diplexed Path
DSS 25, LNA 1 29.6, -1.0, +2.0 K LNA = MASER
DSS 25, LNA 2 43.4, -1.0, +2.0 K LNA = HEMT
DSS 26, LNA 1 (RCP) 25.8 -1.0, +2.0 K LNA = HEMT
DSS 26, LNA 2 (LCP) 26.5 -1.0, +2.0 K LNA = HEMT
DSS 26, LNA 1 & 2 26.2 -1.0, +2.0 K LNA = HEMT
Ka-Band (31800-32300 MHz) Ka-band only operation (X/Ka-band
dichroic plate retracted), referenced to
feedhorn aperture.
DSS 25 29.3, -1.0, +2.0 LNA = HEMT
DSS 26 N/A
Ka-Band (31800-32300 MHz) X/Ka-band operation, referenced to
feedhorn aperture.
DSS 25 32.8, -1.0, +2.0 LNA = HEMT
DSS 26 N/A
Carrier Tracking Loop Noise 0.25-200 Effective one-sided, noise-equivalent
B/W (Hz) carrier loop bandwidth (BL)
Table 8. S-Band Receive Characteristics, DSS 27
Parameter Value Remarks
ANTENNA
Gain (dBi) At peak of gain versus elevation angle
curve, referenced to feedhorn aperture
(feed and feedline losses are accounted for
in system temperature), for matched
polarization; no atmosphere included;
triangular PDF tolerance. See Figures for
elevation dependency.
S-Band 55.1, +0.1, -0.2 dB
Half-Power Beamwidth (deg) Angular width (2-sided) between half-power
points at specified frequency
S-Band 0.242 +/-0.020
Polarization Remotely selected
S-Band RCP or LCP Same as transmit polarization
Ellipticity (dB) Peak-to-peak voltage axial ratio,
RCP and LCP. See definition in Table 2.
S-Band <=1.0
Pointing Loss (dB, 3-sigma)
Angular See module 302 Also see Figure 18
RECEIVER
Frequency Ranges Covered (MHz)
S-Band 2200-2300
Recommended Maximum -90.0 At LNA input terminal
Signal Power (dBm)
Recommended Minimum See Table 12
Signal Power (dBm)
S-Band System Noise With respect to feedhorn aperture, near
Temperature (K) (2200-2300 MHz) zenith, no atmosphere included. See
Figure 13 for elevation dependency.
Tolerances have a triangular PDF.
DSS 27 101, -1.0, +2.0 K LNA = Room temperature HEMT
Incremental Tunability (kHz) 10 Continuously variable tuning around
center frequency available in
+/-15 kHz and +/-300 kHz ranges
Carrier Tracking Loop Noise 1.0-200 Effective one-sided, noise-equivalent
B/W (Hz) carrier loop bandwidth (BL) when using
Block V Receiver
Noise Bandwidth (Hz) 10 +/-10% Effective one-sided threshold noise
30 +/-10% bandwidth (BLO) when using Multifunction
100 +/-10% Receiver
300 +/-10%
1000 +/-10%
3000 +/-10%
Table 9. Gain Reduction Due to Wind Loading, 34-m BWG Antennas
Wind Speed X-Band Gain Reduction (dB)*
(km/hr) (mph)
16 10 0.2
48 30 0.3
72 45 0.4
* Assumes antenna is maintained on-point using CONSCAN or an equivalent.
S-band gain reduction is negligible for wind speeds up to 72 km/h (45 mph).
Worst case with antenna in most adverse orientation for wind.
Table 10. System Noise Temperature Contributions due to 25% Weather
Location Noise Temperature Contribution (K)*
S-band X-band Ka-band
Goldstone (DSS 24, 25, 26 & 27) 1.929 2.292 9.116
Canberra (DSS 34) 2.109 2.654 11.331
Madrid (DSS 54) 2.031 2.545 10.797
* From Table 1 in module 105.
Table 11. Pointing Accuracy and Pointing Loss in Various Wind Conditions
Wind Speed < 4.5 km/s (<10 mph)
Cumulative Distribution(CD) Pointing Error, mdeg Pointing Loss, dB
S-band X-band Ka-band
Mean (54.4%) 1.670 0.001 0.008 0.111
90% 2.825 0.002 0.022 0.319
95% 3.251 0.002 0.029 0.422
99% 3.997 0.003 0.044 0.639
Wind Speed < 8.9 km/s (<20 mph)
Pointing Loss, dB Cumulative Distribution
(CD)
Pointing Error,
mdeg S-band X-band Ka-band
Mean (54.4%) 3.330 0.002 0.031 0.443
90% 5.633 0.007 0.088 1.268
95% 6.483 0.009 0.116 1.679
99% 7.971 0.013 0.176 2.539
Wind Speed < 13.4 km/s (<30 mph)
Pointing Loss, dB Cumulative Distribution
(CD)
Pointing Error,
mdeg S-band X-band Ka-band
Mean (54.4%) 5.000 0.005 0.069 0.999
90% 8.458 0.015 0.198 2.858
95% 9.734 0.019 0.262 3.786
99% 11.968 0.029 0.396 5.724
Table 12. Recommended Minimum Operating Carrier Signal Levels (dBm)
for BWG Antennas Using the Block V Receiver (BVR)*
Band, LNA, and Configuration Receiver Effective Noise Bandwidth (B_L) (Hz)+
0.25 1.0 2.0 20.0 200
S-Band
DSS 24 Non-Diplexed -179.8 -173.8 -170.8 -160.8 -150.8
DSS 34 Non-Diplexed -179.5 -173.4 -170.4 -160.4 -150.4
DSS 54 Non-Diplexed -179.7 -173.7 -170.7 -160.7 -150.7
DSS 24 S-Diplexed -179.0 -173.0 -169.9 -159.9 -149.9
DSS 34 S-Diplexed -178.5 -172.4 -169.4 -159.4 -149.4
DSS 54 S-Diplexed -178.7 -172.6 -169.6 -159.6 -149.6
DSS 27 Diplexed -168.5 -165.5 -155.5 -145.5
X-Band Only
DSS 24 Non-Diplexed -180.6 -174.5 -171.5 -161.5 -151.5
DSS 34 Non-Diplexed -179.8 -173.7 -170.7 -160.7 -150.7
DSS 54 Non-Diplexed -180.9 -174.9 -171.8 -161.8 -151.8
DSS 34 X-Diplexed -178.8 -172.8 -169.8 -159.8 -149.8
DSS 54 X-Diplexed -179.7 -173.7 -170.7 -160.7 -150.7
S/X-band
DSS 24 Non-Diplexed -180.3 -174.3 -171.3 -161.3 -151.3
DSS 34 Non-Diplexed -179.5 -173.5 -170.5 -160.5 -150.5
DSS 54 Non-Diplexed -180.6 -174.6 -171.5 -161.5 -151.5
DSS 34 Diplexed -178.6 -172.6 -169.6 -159.6 -149.6
DSS 54 Diplexed -179.5 -173.4 -170.4 -160.4 -150.4
X-Band LNA-1
DSS 25 Non-Diplexed -180.8 -174.7 -171.7 -161.7 -151.7
DSS 25 Diplexed -179.6 -173.6 -170.6 -160.6 -150.6
DSS 26 Diplexed -180.1 -174.0 -171.0 -161.0 -151.0
* Levels are referenced to LNA input terminals with nominal zenith system noise
temperature and average clear weather (CD=0.25).
+ Bandwidth is centered about the received carrier.
Table 13. Recommended Minimum Operating Carrier Signal Levels (dBm)
for BWG Antennas Using the Block V Receiver (BVR)*
Band, LNA, and Configuration Receiver Effective Noise Bandwidth (B_L) (Hz)+
0.25 1.0 2.0 20.0 200
X-Band LNA-2
DSS 25 Non-Diplexed -178.8 -172.8 -169.8 -159.8 -149.8
DSS 25 Diplexed -178.0 -172.0 -169.0 -159.0 -149.0
DSS 26 Diplexed -180.1 -174.0 -171.0 -161.0 -151.0
Ka-Band Only
DSS 25 -178.8 -172.8 -169.7 -159.7 -149.7
X/Ka-Band
DSS 25 -178.4 -172.4 -169.4 -159.4 -149.4
* Levels are referenced to LNA input terminals with nominal zenith system noise temperature
and average clear weather (CD=0.25).
+ Bandwidth is centered about the received carrier.
Table 14. Recommended Minimum Operating Carrier Signal Levels (dBm)
for DSS 27 HSB Antenna Using the Multifunction Receiver (MFR)*
Band, LNA, and Configuration Receiver Effective Noise Bandwidth (B_L) (Hz)+
10 30 100 300 1000 3000
S-Band
DSS 27 Diplexed -155.5 -150.7 -145.5 -140.7 -135.5 -130.7
* Levels are referenced to LNA input terminals with nominal zenith system noise temperature
and average clear weather (CD=0.25).
+ Indicated bandwidths are one-sided. That is, a value such as "30 Hz" means 30 Hz on each
side of the carrier frequency for a total bandwidth of 60 Hz, and so forth
Figure 1. Functional Block Diagram of DSS 24 Antenna
(Figure omitted in text-only document)
Figure 1. Functional Block Diagram of DSS 24 Antenna
(Figure omitted in text-only document)
Figure 2. Functional Block Diagram of DSS 25 Antenna
(Figure omitted in text-only document)
Figure 3. Functional Block Diagram of DSS 26 Antenna
(Figure omitted in text-only document)
Figure 4. Functional Block Diagram of DSS 34 and DSS 54 Antennas
(Figure omitted in text-only document)
Figure 5. Functional Block Diagram of DSS 27 Antenna
(Figure omitted in text-only document)
Figure 6. DSS 24 (Goldstone) S-Band Receive Gain Versus Elevation Angle,
(Figure omitted in text-only document)
Figure 7. DSS 27 (Goldstone) S-Band Receive Gain Versus Elevation Angle,
(Figure omitted in text-only document)
Figure 8. DSS 34 (Canberra) X-Band Receive Gain Versus Elevation Angle,
(Figure omitted in text-only document)
Figure 9. DSS 54 (Madrid) X-Band Receive Gain Versus Elevation Angle,
(Figure omitted in text-only document)
Figure 10. DSS 25 (Goldstone) X-Band Receive Gain Versus Elevation Angle,
(Figure omitted in text-only document)
Figure 11. DSS 25 (Goldstone) Ka-Band Receive Gain Versus Elevation Angle,
(Figure omitted in text-only document)
Figure 12. DSS 24 (Goldstone) S-Band System Temperature Versus Elevation Angle,
(Figure omitted in text-only document)
Figure 13. DSS 27 (Goldstone) S-Band System Temperature Versus Elevation Angle,
(Figure omitted in text-only document)
Figure 14. DSS 34 (Canberra) X-Band System Temperature Versus Elevation Angle,
(Figure omitted in text-only document)
Figure 15. DSS 54 (Madrid) X-Band System Temperature Versus Elevation Angle,
(Figure omitted in text-only document)
Figure 16. DSS 25 (Goldstone) X-Band System Temperature Versus Elevation
(Figure omitted in text-only document)
Figure 17. DSS 25 (Goldstone) Ka-Band System Temperature Versus Elevation
(Figure omitted in text-only document)
Figure 18. S-Band Gain Reduction Versus Angle off Boresight
(Figure omitted in text-only document)
Figure 19. X-Band Gain Reduction Versus Angle off Boresight
(Figure omitted in text-only document)
Figure 20. Ka-Band Gain Reduction Versus Angle off Boresight
(Figure omitted in text-only document)
Figure 21. Ka-Band Transmit Gain Reduction Due to Aberration Correction
(Figure omitted in text-only document)
Appendix A
Equations for Modeling
A.1 Equations for Gain Versus Elevation Angle
The following equation can be used to generate S-, X-, and Ka-band transmit and
receive gain versus elevation angle curves. Examples of these curves for selected stations and
configurations are shown in Figures 6-11. See paragraph 2.1.1.1 for frequency effect modeling
and module 105 for atmospheric attenuation at weather conditions other than 0%, 50%, and 90%
cumulative distribution.
G(theta) = G_0 - G_1(theta - gamma)^2 - A_ZEN/sin(theta), dBi (A-1)
where
theta = antenna elevation angle (deg.) 6 <= theta <= 90
G_0, G_1, gamma = parameters from Tables A1, A2, and A3
A_ZEN = zenith atmospheric attenuation from Table A-4 or from Table 2 in module 105, dB
A.2 Equations for System Temperature Versus Elevation Angle
The following equation can be used to generate S-, X, and Ka-band system
temperature versus elevation angle curves. Examples of these curves are shown in Figures
12-17. See module 105 for atmospheric attenuation at weather conditions other than 0%, 50%,
and 90% cumulative distribution..
T_op(theta) = T_1 + T_2 * exp(-a * theta) + (255 + 25CD)(1 - 1/(10^(A_ZEN/(10sin(theta))))), K (A-2)
where
theta = antenna elevation angle (deg.), 6 <= theta <= 90
T_1, T_2, a = parameters from Tables A-1, A-2, or A-3
CD = cumulative distribution used to select A_ZEN from Table A-2 or from Table 2 in module 105, 0 < CD < 0.99
A_ZEN = zenith atmospheric attenuation for selected CD from Table A-2 or from Table 2 in module 105, dB.
A.3 Equation for Gain Reduction Versus Pointing Error
The following equation can be used to generate gain reduction versus pointing
error curves, examples of which are depicted in Figures 18, 19, and 20.
delta G(theta) = 10log(exp(-(2.773 * theta^2)/HPBW^2)), dB (A-3)
where
theta = pointing error
HPBW = half-power beamwidth in degrees (from Tables 2 through 8).
A.4 Equation for Transmit Aberration Gain Reduction
The following equation can be used to generate the Ka-band transmit gain
reduction curve depicted in Figure 21.
delta G(phi) = -0.0038 * phi^2, dB
where
phi = transmit beam offset, mdeg.
Table A-1. S-Band Vacuum Gain and System Noise Temperature Parameters
Station and Configuration Vacuum Gain Parameters Vacuum System Noise
Temperature Parameters Figures
G_0+ G_0+ G_1 gamma T_1 T_2 a
Transmit Receive
DSS 24 (Goldstone)
S/X, Non-Diplexed (HEMT) - 56.81 0.000032 90.0 28.34 4.7 0.05 6, 12
S/X, Diplexed (HEMT) 56.1 56.81 0.000032 90.0 34.79 4.7 0.05
DSS 27 (Goldstone)
S-Only, Diplexed (R/T HEMT) 54.4 55.10 0.00004 90.0 101.00 27.0 0.061 7, 13
DSS 34 (Canberra)
S/X, Non-Diplexed (HEMT) - 56.75 0.000037 52.5 30.68 0.0 0.0
S/X, Diplexed (HEMT) 56.1 56.75 0.000037 52.5 39.28 0.0 0.0
DSS 54 (Madrid)
S/X, Non-Diplexed (HEMT) - 56.75 0.000037 45.0 28.88 0.0 0.0
S/X, Diplexed (HEMT) 56.1 56.75 0.000037 45.0 37.48 0.0 0.0
Notes:
+ G0 values are nominal at the frequency specified in Tables 2, 3, 6, or 8. Other parameters
apply to all frequencies within the same band.
Table A-2. X-Band Vacuum Gain and System Noise Temperature Parameters
Station and Configuration Vacuum Gain Parameters Vacuum System Noise
Temperature Parameters Figures
G_0+ G_0+ G_1 gamma T_1 T_2 a
DSS 24 (Goldstone)
X-Only, Non-Diplexed (MASER) - 68.11 0.000027 51.5 23.18 0.0 0.0
S/X, Non-Diplexed
(MASER) - 68.06 0.000027 51.5 24.58 0.0 0.0
DSS 25 (Goldstone)
X/Ka, Non-Diplexed (MASER) - 68.37 0.000028 47.5 22.13 14.0 0.15 10, 16
X/Ka, Non-Diplexed (HEMT) - 68.37 0.000028 47.5 35.93 14.0 0.15
X/Ka, Diplexed (MASER) 67.1 68.37 0.000028 47.5 29.63 14.0 0.15
X/Ka, Diplexed (HEMT) 67.1 68.37 0.000028 47.5 43.43 14.0 0.15
DSS 26 (Goldstone)
X-Only, Diplexed (HEMT-1) 67.1 68.29 0.000028 45.0 25.8 4.5 0.08
X-Only, Diplexed (HEMT-2) 67.1 68.29 0.000028 45.0 26.5 4.5 0.08
Notes:
+ G0 values are nominal at the frequency specified in Tables 4, 6, and 7. Other parameters
apply to all frequencies within the same band.
Table A-2. X-Band Vacuum Gain and System Noise Temperature Parameters (Continued)
Station and Configuration Vacuum Gain Parameters Vacuum System Noise
Temperature Parameters Figures
G_0+ G_0+ G_1 gamma T_1 T_2 a
DSS 34 (Canberra)
X-Only, Non-Diplexed (HEMT) - 68.29 0.000023 47.5 28.00 0.0 0.0
X-Only, Diplexed (HEMT) 67.1 68.29 0.000023 47.5 35.50 0.0 0.0
S/X, Non-Diplexed (HEMT) - 68.24 0.000023 47.5 29.70 0.0 0.0
S/X, Diplexed (HEMT) 67.1 68.24 0.000023 47.5 37.20 0.0 0.0 8, 14
DSS 54 (Madrid)
X-Only, Non-Diplexed (MASER) - 68.29 0.000023 47.5 21.07 4.0 0.1 9, 15
X-Only, Diplexed (MASER) 67.1 68.29 0.000023 47.5 28.62 4.0 0.1
S/X, Non-Diplexed (MASER) - 68.24 0.000023 47.5 22.82 4.0 0.1
S/X, Diplexed (MASER) 67.1 68.24 0.000023 47.5 30.22 4.0 0.1
Notes:
+ G0 values are nominal at the frequency specified in Tables 4, 6, and 7. Other parameters
apply to all frequencies within the same band.
Table A-3. Ka-Band Vacuum Gain and System Noise Temperature Parameters
Station and Configuration Vacuum Gain Parameters Vacuum System Noise
Temperature Parameters Figures
G_0+ G_0+ G_1 gamma T_1 T_2 a
DSS 25 (Goldstone)
Ka-Only, Diplex (HEMT) 79.5 78.98 0.00052 45.0 28.41 2.9 0.013
X/Ka, Diplex (HEMT) 79.5 78.83 0.00052 45.0 31.91 2.9 0.013 11, 17
Notes:
+ G0 values are nominal at the frequency specified in Tables 5 and 7. Other parameters apply
to all frequencies within the same band.
Table A-4. S-, X-, and Ka-Band Zenith Atmospheric Attenuation (A_ZEN)
Station A_ZEN, dB*
CD+ = 0.00 CD+ = 0.50 CD+ = 0.90
S-Band
Goldstone 0.033 0.032 0.031
Canberra 0.036 0.035 0.034
Madrid 0.034 0.033 0.033
X-Band
Goldstone 0.037 0.040 0.047
Canberra 0.040 0.048 0.059
Madrid 0.038 0.045 0.053
Ka-Band
Goldstone 0.116 0.177 0.274
Notes:
* From Table 2 in module 105,
+ CD = cumulative distribution
810-005, Rev. E
DSMS Telecommunications Link
Design Handbook
105, Rev. A
Atmospheric and Environmental Effects
December 15, 2002
Prepared by: Approved by:
----------------------- -----------------------
S.D. Slobin Date A.J. Freiley Date
Antenna System Engineer Antenna Product Domain Service
System Development Engineer
Released by:
[Signature on file in TMOD Library]
------------------------
TMOD Document Release Date
Change Log
Rev Issue Date Affected Paragraphs Change Summary
Initial 1/15/2001 All All
A 12/15/2002 All Provides monthly weather statistics
for all stations and frequency bands
Note to Readers
There are two sets of document histories in the 810-005 document, and these
histories are reflected in the header at the top of the page. First, the entire document is
periodically released as a revision when major changes affect a majority of the modules. For
example, this module is part of 810-005, Revision E. Second, the individual modules also
change, starting as an initial issue that has no revision letter. When a module is changed, a
change letter is appended to the module number on the second line of the header and a summary
of the changes is entered in the module's change log.
Contents
Paragraph Page
1 Introduction.......................................................................................... 6
1.1 Purpose............................................................................................. 6
1.2 Scope............................................................................................... 6
2 General Information .................................................................................. 7
2.1 Atmospheric Attenuation and Noise Temperature....................................................... 7
2.1.1 Calculation of Mean Atmospheric Physical Temperature............................................. 10
2.1.2 Elevation Angle Modeling......................................................................... 10
2.1.3 Calculation of Noise Temperature From Attenuation ............................................... 10
2.1.4 Cosmic Background Adjustment..................................................................... 11
2.1.5 Example of Use of Attenuation Statistics to Calculate Atmospheric
Noise Temperature, T_atm(theta, CD), and T_op(theta, CD) ........................................ 12
2.1.6 Best/Worst Month Ranges of Atmospheric Noise Temperature and Attenuation......................... 12
2.2 Rainfall Statistics................................................................................ 13
2.3 Wind Loading....................................................................................... 14
2.4 Hot Body Noise .................................................................................... 14
2.4.1 Solar Noise...................................................................................... 14
2.4.2 Lunar Noise...................................................................................... 17
2.4.3 Planetary Noise ................................................................................. 18
2.4.4 Galactic Noise .................................................................................. 19
Illustrations
Figure Page
1. Cumulative Distributions of Zenith Atmospheric Noise Temperature at L- & S-Band, Goldstone DSCC..... 20
2. Cumulative Distributions of Zenith Atmospheric Noise Temperature at L- & S-Band, Canberra DSCC...... 21
3. Cumulative Distributions of Zenith Atmospheric Noise Temperature at L- & S-Band, Madrid DSCC........ 22
4. Cumulative Distributions of Zenith Atmospheric Noise Temperature at X-Band, Goldstone DSCC.......... 23
5. Cumulative Distributions of Zenith Atmospheric Noise Temperature at X-Band, Canberra DSCC........... 24
6. Cumulative Distributions of Zenith Atmospheric Noise Temperature at X-Band, Madrid DSCC............. 25
7. Cumulative Distributions of Zenith Atmospheric Noise Temperature at Ka-Band, Goldstone DSCC......... 26
8. Cumulative Distributions of Zenith Atmospheric Noise Temperature at Ka-Band, Canberra DSCC.......... 27
9. Cumulative Distributions of Zenith Atmospheric Noise Temperature at Ka-Band, Madrid DSCC............ 28
10. Probability Distribution of Wind Conditions at Goldstone........................................... 29
11. Solar Radio Flux at 2800 MHz (10.7 cm wavelength) During Solar Cycle 23 (1996-2007)................ 30
12. DSS 15 HEF Antenna X-Band System Noise Temperature Increases Due to the Sun at Various Offset
Angles, Showing Larger Increases Perpendicular to Quadripod Directions............................. 31
13. DSS 16 S-Band Total System Noise Temperature at Various Offset Angles from the Sun................. 32
14. DSS 12 S-Band Total System Noise Temperature at Various Declination and Cross-Declination Offsets
from the Sun....................................................................................... 33
15. DSS 12 X-Band Total System Noise Temperature at Various Declination and Cross-Declination Offsets
from the Sun....................................................................................... 34
16. DSS 13 Beam-Waveguide Antenna X-Band Noise Temperature Increase Versus Offset Angle, March 1996.... 35
17. DSS 13 Beam-Waveguide Antenna Ka-Band Noise Temperature Increase Versus Offset Angle, March 1996... 35
18. Total S-Band System Noise Temperature for 70-m Antennas Tracking Spacecraft Near the Sun
(Derived from 64-m Measurements)................................................................... 36
19. X-Band Noise Temperature Increase for 70-m Antennas as a Function of Sun-Earth-Probe Angle,
Nominal Sun, 23,000 K Disk Temperature............................................................. 37
Tables
Table Page
1. Cumulative Distributions of Zenith Atmospheric Noise Temperature at L- & S-Bands for Goldstone DSCC. 38
2. Cumulative Distributions of Zenith Atmospheric Noise Temperature at L- & S-Bands for Canberra DSCC.. 39
3. Cumulative Distributions of Zenith Atmospheric Noise Temperature at L- & S-Bands for Madrid DSCC.... 40
4. Cumulative Distributions of Zenith Atmospheric Noise Temperature at X-Band for Goldstone DSCC....... 41
5. Cumulative Distributions of Zenith Atmospheric Noise Temperature at X-Band for Canberra DSCC........ 42
6. Cumulative Distributions of Zenith Atmospheric Noise Temperature at X-Band for Madrid DSCC.......... 43
7. Cumulative Distributions of Zenith Atmospheric Noise Temperature at Ka-Band for Goldstone DSCC...... 44
8. Cumulative Distributions of Zenith Atmospheric Noise Temperature at Ka-Band for Canberra DSCC ...... 45
9. Cumulative Distributions of Zenith Atmospheric Noise Temperature at Ka-Band for Madrid DSCC......... 46
10. Cumulative Distributions of Zenith Atmospheric Attenuation at L- and S-Bands for Goldstone DSCC.... 47
11. Cumulative Distributions of Zenith Atmospheric Attenuation at L- and S-Bands for Canberra DSCC .... 48
12. Cumulative Distributions of Zenith Atmospheric Attenuation at L- and S-Bands for Madrid DSCC....... 49
13. Cumulative Distributions of Zenith Atmospheric Attenuation at X-Band for Goldstone DSCC............ 50
14. Cumulative Distributions of Zenith Atmospheric Attenuation at X-Band for Canberra DSCC............. 51
15. Cumulative Distributions of Zenith Atmospheric Attenuation at X-Band for Madrid DSCC............... 52
16. Cumulative Distributions of Zenith Atmospheric Attenuation at Ka-Band for Goldstone DSCC........... 53
17. Cumulative Distributions of Zenith Atmospheric Attenuation at Ka-Band for Canberra DSCC............ 54
18. Cumulative Distributions of Zenith Atmospheric Attenuation at Ka-Band for Madrid DSCC.............. 55
19. Monthly and Year-Average Rainfall Amounts at the DSN Antenna Locations............................. 56
20. Parameters for X-Band Planetary Noise Calculation, plus X-Band and Ka-Band Noise Temperatures
at Mean Minimum Distance from Earth................................................................ 57
1 Introduction
1.1 Purpose
This module provides sufficient information concerning
atmospheric, environmental, and extraterrestrial effects to enable a flight project
to design a telecommunications link at the L-, S-, X, and Ka-band
frequencies used by the DSN.
1.2 Scope
Statistics of atmospheric attenuation and noise temperature at each
tracking antenna site are presented for those microwave frequencies used by the
DSN. In this module, the values of attenuation and noise temperature increase
are given relative to a no-atmosphere (vacuum) condition thus, this
presentation is compatible for use with the vacuum gain and noise temperature
presentations of antenna performance given in modules 101 for 70-m antennas,
102 for 26-m antennas, 103 for 34-m high-efficiency (HEF) antennas, and 104 for
34-m beam-waveguide (BWG) antennas.
Statistics of wind speed at Goldstone are given. These are used both
to determine the statistics of antenna gain reduction due to wind loading and
also to ascertain the percentage of time an antenna will be unusable due to
excessive wind speed.
Extraterrestrial effects are primarily the increased system noise
temperature due to hot body noise from the Sun, Moon, planets, and galactic
radio sources. These effects are significant only when the antenna beam is in
the vicinity of these noise sources during tracking of spacecraft.
Charged-particle effects are given in module 106, Solar Corona and
Solar Wind Effects.
2 General Information
2.1 Atmospheric Attenuation and Noise Temperature
The principal sources of atmospheric attenuation and noise
temperature weather effects are oxygen, water vapor, clouds, and rain. These
two effects are related, and higher atmospheric attenuation produces a higher
noise contribution. Also, atmospheric effects generally increase with
increasing frequency. Ka-band effects are larger than X-band effects, which
are larger than S-band and L-band effects.
In the 810-005 antenna performance modules (modules 101, 102, 103, and
104), effective antenna gain (vacuum gain minus atmospheric attenuation) is
presented in the figures for various atmospheric attenuation values. Strictly
speaking, the gain of an antenna is not a function of atmospheric attenuation;
however for stand-alone use, the effective gain, including atmospheric loss, is
a useful concept, and the expressions for gain in the appendices of those
modules include a term for atmospheric attenuation. Similarly, system operating
noise temperature as presented in the appendices of those modules also includes
a term for atmospheric noise contribution, although the antenna temperature (due
to spillover, LNA contribution, waveguide loss, etc.) is also not a function of
atmosphere contribution. The vacuum system noise temperature as given in those
modules includes the nearly constant contribution from the cosmic background,
which adds to the basic antenna temperature value.
Design control tables used for telecommunications link design
typically carry separate entries for atmospheric attenuation of the received or
transmitted signal and atmospheric noise contribution as a function of elevation
angle and weather condition. It is important in those DCTs that the antenna gain
and system operating noise temperature values reflect the vacuum performance of
the antenna, so as to prevent double-bookkeeping of the atmospheric attenuation
and noise temperature contributions.
The atmospheric models presented here give L-band (1.7 GHz), S-band
(2.3 GHz), X-band (8.4 GHz), and Ka-band (32.0 GHz) atmospheric noise
temperature and attenuation statistics in the form of cumulative distributions
(CDs) for each effect. A cumulative distribution of 0.90 (90% weather) means
that 90% of the time a particular weather effect (noise temperature or
attenuation) is less than or equal to a given value. Conversely, that
particular effect is exceeded only 10% of the time. Qualitatively, the weather
conditions associated with selected cumulative distributions are described as
follows:
CD = 0.00 clear dry, lowest weather effect
CD = 0.25 average clear weather
CD = 0.50 clear humid, or very light clouds
CD = 0.90 very cloudy, no rain
CD > 0.95 very cloudy, rain
By their very natures, clouds and rain are poorly modeled, and the
water vapor radiometer data used here are sparse for the larger weather
effects, which are exceeded only 5% of the time.
The Ka-band model presented here is based on actual water vapor
radiometer noise temperature measurements made at 31.4 GHz at all three DSN
sites (Goldstone, Canberra, and Madrid). Used in the modeling were 66 months of
Goldstone data covering the period October 1993 through August 2002, 35 months
of Canberra data covering the period June 1999 through August 2002, and 112
months of Madrid data covering the period September 1990 through August 2002.
There were missing months of data from each station. Note also that different
numbers of months of data went into the model for each of the separate months
(e.g., there may have been 6 Februaries, but only 4 Marches). It is felt that
because of the large amount of Madrid data (more than 9 years), the results will
fairly accurately represent true long-term statistics. The 5-1/2 years of
Goldstone data will give a moderately accurate long-term model. The three years
of Canberra data will probably not give a very accurate long-term model, and
future updates of the Canberra model are likely to show relatively large changes
in the distributions. Cumulative distributions at 31.4 GHz for each of the 12
months were calculated, then increased by 0.3 K (the oxygen-only difference due
to frequency) to create a model for 32 GHz. A year-average model was developed
by calculating the average noise temperature of all the 12 months, at each CD
level.
L-/S-band and X-band statistics were created from the Ka-band (32
GHz) statistics by subtracting out the 0% CD baseline (calculated for
nominal temperatures and pressures, with 0% relative humidity), frequency
squaring to the appropriate frequency (for example, [8.42/32.0]^2 ) and then
adding in the 0% CD baseline at the new frequency. Note that the 0% CD
baselines for the DSN sites differ because of different heights above
sea level.
Atmospheric attenuation statistics were created from the noise
temperature statistics by methods given in Sections 2.1.1 and 2.1.3 below.
The year-average attenuation statistics were calculated from the year-average
noise temperature values rather than by calculating the average of all the
monthly attenuations. These two methods give very slightly different results.
It should be noted that although the noise temperature statistics are
the best qualitative measures for comparison of different locations and
different frequencies, especially when dealing with low-noise systems (where the
atmospheric noise is a large part of the total system noise temperature), the
basic data base of atmospheric effects is actually the attenuation statistics.
Given a station location, frequency, and CD of interest, the attenuation data
base value is extracted, modeled to the elevation angle of interest (Section
2.1.2), and then the appropriate atmospheric noise temperature is calculated
(Section 2.1.3). In this way, the original zenith noise temperature statistics
(Tables 1 through 9) can be re-calculated from the zenith attenuation values
(Tables 10 through 18) using the method given in Section 2.1.3.
The atmospheric models thus generated for a particular complex (for
example, Goldstone) should be used for all antennas at that complex (for
example, DSS 14, DSS 15, DSS 24, etc.), regardless of the small altitude
differences among the antennas.
Zenith atmospheric noise temperature statistics for the three DSN
sites at S-band are provided in Tables 1 through 3. Tables 4 through 6 provide
similar statistics for X-band and Tables 7 through 9 cover Ka-band. The tables
include the maximum and minimum value for each CD level, the year average for
that CD level and the average value for each month. These noise temperature
statistics should be used only in a qualitative sense to describe the relative
levels of atmospheric noise contributions at different locations and cumulative
distributions. They should not be used for elevation modeling as this is
properly performed using the calculated attenuation at a given elevation angle
as a starting point and following the process that is described below.
The use of these statistics depends on the context in which the
antenna temperature is stated. When a nominal antenna zenith T_op (operating
system noise temperature) is stated, it is considered to include the CD = 25%
(average clear sky) value for the appropriate frequency and location. However,
"vacuum" antenna temperatures are sometimes used to describe the performance of
an antenna independent of location. In this case the operating system noise
temperature should be referred to as T_(op, vac).
Tables 10 through 18 provide similar presentations for zenith
atmospheric attenuation. It can be noted that the L-/S-band attenuations do
not monotonically increase as a function of CD, whereas the corresponding
noise temperatures do. This is an artifact of the relationship between the
modeled mean physical temperature of the atmosphere and the noise temperature
used to calculate the corresponding attenuation. This relationship is seen
below. In any case, the atmospheric effect at L-/S-band is nearly constant (to
within 0.1 K and 0.003 dB over the CD range from 0% to 90%), and this small
anomaly does not contribute to significant errors in modeling
telecommunications performance.
The tolerances of atmospheric noise temperature and attenuation, as
given in Tables 1 through 18, should be considered to be 5% of the stated
values at zenith, or 5% of the values calculated for elevation angles other
than zenith. (see Section 2.1.5, below).
Figures 1, 2, and 3 show the L-/S-band noise temperature statistics
for Goldstone, Canberra, and Madrid respectively. Figures 4, 5, and 6 show X-
band statistics for the three complexes. Figures 7, 8, and 9 provide the Ka-band
statistics. On each figure, the year-average cumulative distribution, the
minimum envelope value, and the maximum envelope values are given for all the
individual months at each CD value stated in Tables 1-9. The year-average model
from the previous revision of module 105 (dated November 30, 2000) is also given
to aid the user in assessing the changes from one model to the next. Curves of
zenith attenuation are not given, although using a rule-of thumb that a medium
with 1 dB attenuation radiates a noise temperature of approximately 60 K, the Ka-
band curves can be used to make rough estimates of the zenith attenuation at the
various frequencies. This relationship is nearly linear over the range from 0 to
1 dB.
For Ka-band, using 90% CD as a reference point, it is seen
qualitatively that the Goldstone year-average model shows better weather than
the previous module 105 presented; Canberra shows identical weather, although
better at higher CDs; and Madrid slightly worse at 90% and slightly better
above 96%.
For other nearby frequencies within the L-, S-, X-, and Ka-bands,
the weather-effects models presented here should be used without modification.
2.1.1 Calculation of Mean Atmospheric Physical Temperature
The mean physical temperature of the atmosphere is modeled to be a
function of weather condition, or cumulative distribution. This reflects the
assumption that those effects that are of larger value (for example, high noise
temperature) occur closer to the surface and hence are at a higher average
physical temperature than those that have a lesser effect. The mean atmospheric
physical temperature is modeled as
T_p = 255 + 25 x CD , K (1)
where
CD = cumulative distribution of weather effect (0.0 <= CD <= 0.99).
Note that the maximum value of T_p thus becomes nearly 280 K.
2.1.2 Elevation Angle Modeling
Only the attenuation should be modeled as a function of elevation
angle. The atmospheric noise temperature contribution at any elevation angle
can be calculated from the modeled attenuation at that elevation angle.
Elevation angle modeling can be performed using either a flat-Earth or a
round-Earth model. A flat-Earth model is used here, wherein the attenuation
increases with decreasing elevation angle:
A(theta) = A_zen x AM = A_zen/sin(theta), dB (2)
where
theta = elevation angle of antenna beam
A_zen = zenith atmospheric attenuation (dB), as given in Tables 10 through 18
AM = number of air masses (1.0 at zenith)
The flat-Earth approximation produces a slightly higher attenuation
then would be obtained with a round-Earth model for low elevation angles but is
valid to within 1% to 3% at a 6-deg elevation angle, depending on the frequency
and the amount of water vapor in the atmosphere.
2.1.3 Calculation of Noise Temperature From Attenuation
An attenuating atmosphere creates a noise temperature contribution
to ground antenna system temperature. The atmospheric noise temperature at
any elevation angle (theta) is calculated from the attenuation by
T_atm(theta) = T_p[1 - 1/(L(theta))], K (3)
where
T = mean physical temperature of atmosphere (K), calculated above
L(theta) = loss factor of atmosphere = 10^(A(theta)/10)
A(theta) = atmospheric attentuation at any elevation angle (dB), calculated above
Note that typical values of L range from about 1.01 to 2.0
2.1.4 Cosmic Background Adjustment
The noise temperature contribution of the cosmic background is
reduced by atmospheric attenuation. For the bands of interest, the effective
cosmic background noise before atmospheric attenuation is
T_c = 2.7 (L-band and S-band)
= 2.5 (X-band)
= 2.0 (Ka-band)
With atmosphere, the effective cosmic background effect is
T'_c(theta) = T_c/(L(theta)), K (4)
where
T_c = effective cosmic background noise (K) without atmosphere
L(theta) =loss factor of atmosphere at the elevation angle of interest, as
calculated from Section 2.1.3.
The expressions for T_(op, vac) in the telecommunications interface
modules (for example, module 101) include the effective cosmic background
contribution reduced by the effects of average clear weather. These values are
within a few tenths of a Kelvin of the values given above, and variations in
T'_c as a function of weather condition and elevation angle are
typically neglected, as being at the sub-1K level.
2.1.5 Example of Use of Attenuation Statistics to Calculate Atmospheric Noise
Temperature, T_atm(theta, CD), and T_op(theta, CD)
The following example will show a typical calculation of atmospheric
noise temperature and attenuation for a particular situation. The parameters
for the example are
DSS 43, Canberra
Ka-band (32 GHz)
90% year average weather (CD = 0.90)
20-deg elevation angle (2.924 air masses)
From Table 17, the year average zenith attenuation is given as
A_zen = 0.404 dB.
The attenuation at 20-deg elevation is
A(20 degrees, 90%) = 0.404/sin(20) = 1.181 dB
The loss factor L at 20-deg elevation is
L(20 degrees, 90%) = 10^0.1181 = 1.312
The atmospheric mean physical temperature is
T_p = 255 + 25 x 0.90 = 277.5 K
The atmospheric noise temperature at 20-deg elevation is
T_atm(20 degrees, 90%)= 277.5(1 - 1/1.312) = 65.991 K
The operating system noise temperature at any elevation angle
and for any weather condition is given by
T_op (theta,CD)= T_(op,vac)(theta) + T_atm(theta, CD), K (5)
where
T_(op,vac)(theta) = vacuum system temperature at elevation angle theta from
the appropriate antenna performance module
(101, 102, 103 or 104).
2.1.6 Best/Worst Month Ranges of Atmospheric Noise Temperature and
Attenuation
Although the absolute accuracy of the 31.4-GHz water vapor radiometer
measurements used to create the noise temperature statistics is thought to be on
the order of the values stated in paragraph 2.1, the month-to-month variation of
average noise temperature at any CD varies much more than this at all values of
cumulative distribution greater than about 10%. A particular month might be the
"worst" at the 90% CD level, but merely "moderate" at lower CD levels. An
example is a winter month that has a large amount of rain but when not raining
has low humidity and low noise temperature contribution. At this time, there are
insufficient data to characterize "best" and "worst" months individually;
however, tolerances on the mean statistics as given in Tables 1 through 18 can
give the user a feeling of what yearly variations in atmospheric effects may be
expected.
Inspection of Tables 1 through 18 and Figures 1 through 9 will show
that fictitious "best month" and "worst month" statistics can be generated from
the values giving the minimum and maximum envelope values of noise temperature
and attenuation, without regard to the variability among the months as a
function of CD. At high values of CD, the adverse (maximum envelope) yearly
tolerances can be as high as 40% of the year-average value of an effect. It
should be noted that adverse tolerances for both noise temperature and
attenuation give INCREASES from the values in Tables 1 through 18. An adverse
VALUE is a mean PLUS the adverse tolerance. For mission planning purposes, with
no need to create a model for a specific month, it may be sufficient to use the
year-average value at a particular CD, and use the maximum/minimum envelope
values to define very conservative adverse/favorable tolerances, with triangular
distribution. For specific-month planning purposes, it may be sufficient to use
the values given in Tables 1 through 18, with +/-5% tolerances (triangular
distribution) as stated above. A very conservative approach (acknowledging that
any individual month in the future can be well outside the historical range of
available data) would be to use the "maximum" envelope as the model for a
possible "bad" month. Note also, that for particular months, characterized by
"bad weather", year-to-year variation of noise temperature and attenuation
statistics can be quite large.
2.2 Rainfall Statistics
To assist the user in determining which months may have large
rainfall-related atmospheric noise temperature and attenuation increases,
rainfall data are presented for the three DSN antenna locations. Months with
large average rainfall amounts may not necessarily correspond to months with
large noise temperature and attenuation values. Comparison with Tables 1
through 18 should be made.
Table 19 presents the monthly and year-average rainfall amounts for
the three DSN antenna locations. The Goldstone data (1973-2000) were taken at
the administration center, located near the middle of the Goldstone antenna
complex. Some antennas may be located as much as 10 miles from this location.
The Canberra data (1966-2002) were taken at the Tidbinbilla Nature Reserve,
located about 3 miles southwest of the antenna site. The Madrid data (1961-1990)
are the averages of the rainfall at two locations: Avila, about 20 miles
northwest of the antenna site, and Madrid (Quatro Vientos) about 20 miles east
of the antenna site. Although these averages may not exactly reflect the
rainfall at the antenna site, the relative monthly amounts are undoubtedly
correct.
2.3 Wind Loading
The effect of wind loading must be modeled probabilistically, since
wind velocity varies randomly over time and space. Figure 10 shows the
probability distribution of wind speed for Goldstone. Similar data for the
Madrid and Canberra complexes will be supplied when available. The wind load on
a particular antenna is dependent on the design of that antenna. Consequently,
information about wind-load effect on antenna gain is listed in the appropriate
antenna module.
Statistics show that Goldstone is the windiest of the three Deep
Space Network antenna complexes. The DSS 14 70-m antenna is stowed (pointed
vertically) when wind gusts exceed 55 mph (88 km/hr). The frequency of
occurrence of this event can be deduced from a relationship between wind gusts
and average wind speed. This relationship is found to be: maximum hourly wind
speed = 0.62 x strongest gust. Thus, for 55-mph (88 km/hr) gusts, the maximum
hourly wind speed is found to be 34 mph (55 km/hr). From Figure 10, it is seen
that this speed is exceeded approximately 2 % (175 hours) of the year and 4 %
(29 hours) of the worst month. Actual practice has shown that no antenna has
been stowed more than about 10 hours per year due to excessive wind-gust
occurrences.
2.4 Hot Body Noise
2.4.1 Solar Noise
The increase in system noise when tracking near the Sun depends on the
intensity of solar radiation at the received frequency and on the position of the
Sun relative to the antenna gain pattern. The subreflector support structure
(typically a quadripod, but a tripod at the DSS 13 BWG antenna) introduces
nonuniformities in the sidelobe structure. Increases in noise temperature are
typically greater in directions at right angles to the planes established by the
subreflector support legs and the center of the reflector surface. Thus, a
quadripod-type antenna will have four enhanced regions of noise temperature, and
a tripod-type antenna will have six. With an azimuth-elevation (AZ-EL) or X-Y
mounted antenna, the plane containing the Sun-Earth-probe (SEP) angle will
rotate through the sidelobes during a tracking pass. This causes the solar noise
to fluctuate during a track even if the SEP angle is constant.
A large number of measurements were made at Goldstone from 1987 to
1996 to determine the system noise temperature effects of tracking near the
Sun (within about five deg from the center of the solar disk). These
measurements were made at S-, X-, and Ka-bands on both 26- and 34-meter
antennas.
Figure 11 shows the 10.7-cm (2800-MHz) solar radio flux during solar
cycle 23 (1996-2007, the expected "maximum" should have occurred in late 2000 or
early 2001). The flux is measured in solar flux units (SFU) where one SFU = 1 x
10^-22 W/m^2/Hz. Updated solar flux predictions can be found at the National
Oceanic and Atmospheric Administration (NOAA) Space Environment Center web site
(Solar Cycle Progression and Prediction
Plots). Solar flux predictions can be used to model S- and X-band solar noise
temperature contributions using the ratio of predicted solar flux to the solar
flux that existed at the time the antenna noise temperatures were measured.
The general characteristic of the 11-year cycle of 2800-MHz solar flux
is a rapid rise to a peak approximately 4-5 years after the minimum, followed by
a 7-6 year gradual decrease. From cycle to cycle, the peak flux can vary by as
much as a factor of two. The 10.7-cm flux is varied during solar cycle 23 from a
minimum of about 70 SFU during 1996 to a maximum of about 190 +/- 20 SFU during
2000-2001 and returning to an expected minimum of about 70 SFU during 2006.
Figure 12 shows X-band system noise temperature increases as measured
at the Goldstone DSS 15 HEF antenna. These measurements show the increased
effect for the Sun located (offset) at right angles to the quadripod legs. The
quadripod legs are arranged in an "X" configuration, with 90-deg spacing. The
measurements were made in November 1987 (near the beginning of the solar cycle)
with a measured 2800-MHz flux value of 101 SFU and an 8800MHz flux value of 259
SFU. The following expression may be used as an upper limit of X-band solar
noise contribution at DSS 15 as shown in Figure 12.
T_sun = 800e^(-2.0*theta) , K (6)
where
theta = offset angle between center of beam and center of solar disk, deg
Figure 13 shows S-band (2295 MHz) total system noise temperature
measurements made on the Goldstone DSS 16, 26-m antenna on December 20, 1989.
This antenna has no quadripod, and it can be assumed that the noise
temperature values shown are independent of solar "clock angle" around the
center of the antenna beam. The reported 2800MHz solar flux at the time of the
experiment was 194 SFU; at 8800 MHz it was 290 SFU. Note that compared to the
November 1987 flux (Figure 12), the 2800-MHz flux has nearly doubled, but the
8800-MHz flux has only increased about 12 percent. The S-band solar
contribution shown in Figure 13 can be modeled as
T_sun = 1400e^(-1.4*theta) , K (7)
where
theta = offset angle between center of beam and center of solar disk, deg
Figures 14 and 15 are contour plots of the DSS 12, 34-m HA-DEC total
system noise temperature versus declination and cross-declination antenna
pointing offsets. DSS 12 has been decommissioned since the measurements were
made, but the figures are included because they are representative of the
effects of the quadripod on solar noise at other antennas. The quadripod legs
are arranged in a "+" configuration with 90-deg spacing, hence the peaks at
right angles to the legs.
Figure 14 is a contour plot of total S-band system noise
temperature versus declination and cross-declination antenna pointing
offsets at DSS 12.The contour interval is 50 K. These measurements were made
on January 12, 1990. On this day the reported 2800-MHz solar flux was 173
SFU.
Figure 15 is a contour plot of total X-band system noise
temperature versus declination and cross-declination antenna pointing
offsets at DSS 12. The contour interval, measurement date, and flux values
are identical with those in Figure 14. The reported 8800-MHz solar flux was
272 SFU.
Figures 16 and 17 show the X-band (8.4-GHz) and Ka-band (32-GHz) solar
noise contributions at the DSS 13, 34-m research and development beam waveguide
antenna as a function of offset angle from the center of the sun. These data
were taken during mid-March, 1996, when the 10.7-cm solar flux was about 70 SFU
(the minimum at the end of solar cycle 22 and at the beginning of solar cycle
23) and should be considered as representative of what is expected at the
operational DSN beam waveguide antennas.
The following expressions give an approximate upper envelope for
the noise contributions shown in Figures 16 and 17 as a function of offset
angle
T_sun = | 1400e^(-5.1*theta), 0.35 < theta <= 0.75deg , at X-band (8)
| 86e^(-1.4*theta), theta > 0.75deg
T_sun = | 5000e^(-6.6*theta), 0.35 < theta <= 0.75deg , at Ka-band. (9)
| 100e^(-1.4*theta), theta > 0.75deg
At offset angles less than 0.35 deg (0.08 deg from the edge of the
solar disk), solar noise contributions are likely to be in excess of 300 K
at both frequencies. At offsets greater than 4.0 degrees, the solar
contribution is negligible.
All noise contribution expressions given above should be compared with
values shown in the corresponding figures to assess their validity. Note that
these expressions should be considered valid only for the flux values given at
the time of measurement. For predictive purposes, Figure 11 may be used to
obtain future predicted 2800-MHz solar flux, and the noise contributions at S-
and X-band can be modeled as described below.
During the 11-year solar cycle, the S-band flux varies by a factor of
3 (reference Figure 11) while the corresponding X-band flux varies by a factor
of 2. For cycle 23, when the S-band range is expected to be from 70 SFU to as
much as 210 SFU, the X-band range is predicted to be from about 200 SFU to about
400 SFU. The predicted X-band flux can be derived from the predicted S-band flux
by the following expression.
FLUX,X = 200 + 200(FLUX, S-70)/140 (10)
For example, in January 2003 the mean S-band flux is predicted to
be 125 SFU (from Figure 11). The mean predicted X-band flux would be 264 SFU.
The predicted solar noise contribution can be calculated based on
measured noise contributions described above. For example, using the equation
provided for Figure 12 (Equation 6) and the predicted X-band solar flux in
January of 2002 (264 SFU), the predicted X-band solar noise contribution for a 2-
degree offset angle using the 34-m HEF antenna would be
T_sun = (264/259)(800e^(-2.0x2.0)) = 14.6K (11)
At Ka-band, the solar flux varies little over the solar cycle and
the relationship between noise temperature increase and offset angle depicted
in Figure 17 can be used at all times.
Figure 18 shows examples of measured S-band system noise temperature
made with a 64-m antenna tracking Pioneer 8 (November 1968, near the solar
maximum) and Helios (April 1975, near the solar minimum). For all practical
purposes, these curves may be used to predict S-band performance for the DSN 70-
m antennas. The "maximum" and "minimum" curves for each month show the solar
"clock angle" effect due to sidelobes at right angles to the quadripod legs.
Figure 19 shows a theoretical curve of X-band 70-m antenna noise
temperature as a function of SEP angle. This curve is generated based on an
assumed X-band blackbody disk temperature of 23,000 K, representing an "average"
value during the solar cycle. An expression giving quiet Sun brightness
temperature, T_b (K), as a function of wavelength (mm) has been
found to be
T_b = 5672 * lambda^0.24517, K (12)
For S-band (2.3 GHz), T_b = 18700 K. For X-band (8.5 GHz) T_b = 13600
K. For Ka-band (32 GHz) T_b = 9750 K. The active Sun may be expected to have an
X-band brightness temperature of as much as two to four times as high as the
13600 K calculated above.
2.4.2 Lunar Noise
For an antenna pointed near the Moon, a noise temperature
determination similar to that made for the Sun should be carried out. The
blackbody disk temperature of the Moon is about 240 K, and its apparent
diameter is almost exactly that of the Sun's (approximately 0.5 deg). Figures
12 through 19 may be used for lunar calculations, with the noise temperature
values scaled by 240/23000. Figures 13, 14, 15, and 18 include clear-sky system
noise temperatures, which must be subtracted out before scaling in order to
determine the lunar noise temperature increase. Nevertheless, at offset angles
greater than 2 deg, the lunar noise contribution is negligible.
2.4.3 Planetary Noise
The increase in system noise temperature when tracking near a
planet can be calculated by the formula
T_pl = (T_k * Gd^2/(16R^2))e^(-2.77(theta/theta_0)^2), K (13)
where
T_k =blackbody disk temperature of the planet, K
d = planet diameter, km
R = distance to planet, km
theta = angular distance from planet center to antenna beam center
theta_0 = antenna half-power beamwidth (full beamwidth at half power)
G = antenna gain, ratio 10^(G(dBi)/10), including atmospheric attenuation.
Table 20 presents all the parameters needed for calculation of
planetary noise contributions. Also given are the maximum values of expected X-
band noise contributions for the mean minimum distance from Earth, with the
antenna beam pointed at the center of the planet (theta=0). Corresponding S-band
noise temperature increases will be approximately 1/13 as large as the X-band
increases because of the lower antenna gain (wider beamwidth) at the lower
frequency.
In the case of Jupiter, there is a significant and variable non-
thermal component of the noise temperature. Thus the effective blackbody disk
temperature at S-band appears to be much higher than at X-band. The S-band noise
temperature increase will be approximately 1/6 the X-band values for average
Jupiter emission; it will be about 1/3 the X-band values for maximum Jupiter
emission. Except for Venus and Jupiter at inferior conjunction (minimum
distance), the noise contribution from the planets at S-band is negligible.
The expression for T_pl assumes that the angular extent of the
radiating source is small compared to the antenna beamwidth. This approximation
is adequate at X-band except for Venus near inferior conjunction (apparent
diameter = 0.018 deg) using a 70-m antenna at X-band (beamwidth = 0.032 deg). At
Ka-band with a 34-m antenna (beamwidth = 0.0174 deg), the approximation is not
adequate for Venus near inferior conjunction and may not be adequate for Mars
near inferior conjunction (apparent diameter = 0.005 deg). The expression also
aassumes that the antenna main beam has a Gaussian shape, with circular
symmetry. Antenna gains and half-power beamwidths are given in modules 101, 102,
103, and 104.
2.4.4 Galactic Noise
The center of the Milky Way galaxy is located near -30 degrees
declination, 17 h 40 min right ascension. It is possible for a spacecraft with a
declination of -30 deg to be in the vicinity of the galactic center, and an
increase of system noise temperature would then be observed. A declination of
-30 degrees is not typically achieved by spacecraft moving in the plane of the
ecliptic, but there are some circumstances (for example, a flight out of the
ecliptic) where this location may be observed. Galactic noise temperature
contributions at frequencies above 10 GHz are typically insignificant. At S-
band, looking directly at the galactic center, a noise temperature increase of
about 10 K would be observed. A map of the galactic noise distribution can be
seen in chapter 8 of the classic reference J. D. Kraus, Radio Astronomy, Cygnus-
Quasar Books, Powell, Ohio, 1986.
Figure 1. Cumulative Distributions of Zenith Atmospheric Noise Temperature at L-
Band and S-Band, Goldstone DSCC
(Figure omitted in text-only document)
Figure 2. Cumulative Distributions of Zenith Atmospheric Noise Temperature at L-
Band and S-Band, Canberra DSCC
(Figure omitted in text-only document)
Figure 3. Cumulative Distributions of Zenith Atmospheric Noise Temperature at L-
Band and S-Band, Madrid DSCC
(Figure omitted in text-only document)
Figure 4. Cumulative Distributions of Zenith Atmospheric Noise Temperature at X-
Band, Goldstone DSCC
(Figure omitted in text-only document)
Figure 5. Cumulative Distributions of Zenith Atmospheric Noise Temperature at X-
Band, Canberra DSCC
(Figure omitted in text-only document)
Figure 6. Cumulative Distributions of Zenith Atmospheric Noise Temperature at X-
Band, Madrid DSCC
(Figure omitted in text-only document)
Figure 7. Cumulative Distributions of Zenith Atmospheric Noise Temperature at Ka-
Band, Goldstone DSCC
(Figure omitted in text-only document)
Figure 8. Cumulative Distributions of Zenith Atmospheric Noise Temperature at Ka-
Band, Canberra DSCC
(Figure omitted in text-only document)
Figure 9. Cumulative Distributions of Zenith Atmospheric Noise Temperature at Ka-
Band, Madrid DSCC
(Figure omitted in text-only document)
Figure 10. Probability Distribution of Wind Conditions at Goldstone
(Figure omitted in text-only document)
Figure 11. Solar Radio Flux at 2800 MHz (10.7 cm wavelength) During Solar Cycle 23 (1996-2007)
(Figure omitted in text-only document)
Figure 12. DSS 15 HEF Antenna X-Band System Noise Temperature Increases Due to
the Sun at Various Offset Angles, Showing Larger Increases Perpendicular
to Quadripod Directions
(Figure omitted in text-only document)
Figure 13. DSS 16 S-Band Total System Noise Temperature at Various Offset Angles from the Sun
(Figure omitted in text-only document)
Figure 14. DSS 12 S-Band Total System Noise Temperature at Various Declination
and Cross-Declination Offsets from the Sun
(Figure omitted in text-only document)
Figure 15. DSS 12 X-Band Total System Noise Temperature at Various Declination
and Cross-Declination Offsets from the Sun
(Figure omitted in text-only document)
Figure 16. DSS 13 Beam-Waveguide Antenna X-Band Noise Temperature Increase
Versus Offset Angle, March 1996
(Figure omitted in text-only document)
Figure 17. DSS 13 Beam-Waveguide Antenna Ka-Band Noise Temperature Increase
Versus Offset Angle, March 1996
(Figure omitted in text-only document)
Figure 18. Total S-Band System Noise Temperature for 70-m Antennas Tracking
Spacecraft Near the Sun (Derived from 64-m Measurements)
(Figure omitted in text-only document)
Figure 19. X-Band Noise Temperature Increase for 70-m Antennas as a Function of
Sun-Earth-Probe Angle, Nominal Sun, 23,000 K Disk Temperature
(Figure omitted in text-only document)
Table 1. Cumulative Distributions of Zenith Atmospheric Noise Temperature at L-
and S-Bands for Goldstone DSCC, K
CD January February March April May June
0.000 1.917 1.917 1.917 1.917 1.917 1.917
0.100 1.923 1.923 1.923 1.924 1.926 1.925
0.200 1.925 1.925 1.925 1.927 1.929 1.928
0.250 1.926 1.925 1.926 1.927 1.930 1.929
0.300 1.927 1.927 1.927 1.929 1.932 1.930
0.400 1.928 1.928 1.929 1.930 1.935 1.933
0.500 1.930 1.930 1.931 1.932 1.938 1.936
0.600 1.933 1.932 1.932 1.934 1.941 1.941
0.700 1.938 1.935 1.935 1.936 1.945 1.947
0.800 1.945 1.940 1.938 1.939 1.950 1.952
0.850 1.951 1.945 1.941 1.940 1.954 1.955
0.900 1.963 1.954 1.945 1.943 1.961 1.961
0.925 1.978 1.961 1.947 1.945 1.967 1.967
0.930 1.981 1.963 1.948 1.945 1.968 1.968
0.950 2.002 1.975 1.952 1.948 1.983 1.975
0.960 2.017 1.984 1.957 1.950 1.990 1.981
0.975 2.059 2.005 1.973 1.956 2.010 2.001
0.980 2.075 2.015 1.982 1.963 2.016 2.011
0.990 2.142 2.051 2.022 1.992 2.042 2.051
Table 1 (Cont'd). Cumulative Distributions of Zenith Atmospheric Noise
Temperature at L- and S-Bands for Goldstone DSCC, K
CD July August September October November December Minimum Year Maximum
Average
0.000 1.917 1.917 1.917 1.917 1.917 1.917 1.917 1.917 1.917
0.100 1.929 1.930 1.932 1.927 1.924 1.922 1.922 1.926 1.932
0.200 1.934 1.935 1.935 1.930 1.926 1.925 1.925 1.929 1.935
0.250 1.936 1.937 1.936 1.930 1.927 1.925 1.925 1.930 1.937
0.300 1.938 1.940 1.939 1.932 1.929 1.927 1.927 1.931 1.940
0.400 1.942 1.945 1.943 1.935 1.931 1.928 1.928 1.934 1.945
0.500 1.947 1.951 1.948 1.937 1.934 1.930 1.930 1.937 1.951
0.600 1.954 1.955 1.952 1.940 1.939 1.932 1.932 1.941 1.955
0.700 1.962 1.959 1.958 1.943 1.943 1.935 1.935 1.945 1.962
0.800 1.969 1.963 1.964 1.948 1.948 1.941 1.938 1.950 1.969
0.850 1.972 1.967 1.967 1.952 1.952 1.947 1.940 1.954 1.972
0.900 1.977 1.972 1.975 1.958 1.958 1.957 1.943 1.960 1.977
0.925 1.981 1.976 1.980 1.961 1.961 1.964 1.945 1.966 1.981
0.930 1.982 1.976 1.980 1.961 1.961 1.967 1.945 1.967 1.982
0.950 1.987 1.983 1.986 1.966 1.965 1.985 1.948 1.975 2.002
0.960 1.991 1.987 1.992 1.970 1.968 1.997 1.950 1.982 2.017
0.975 2.003 2.000 2.008 1.983 1.978 2.028 1.956 2.000 2.059
0.980 2.011 2.001 2.024 1.990 1.989 2.042 1.963 2.010 2.075
0.990 2.049 2.009 2.098 2.025 2.031 2.098 1.992 2.051 2.142
Table 2. Cumulative Distributions of Zenith Atmospheric Noise Temperature at
L- and S-Bands for Canberra DSCC, K
CD January February March April May June
0.000 2.085 2.085 2.085 2.085 2.085 2.085
0.100 2.108 2.116 2.121 2.106 2.100 2.099
0.200 2.115 2.123 2.127 2.111 2.103 2.105
0.250 2.117 2.127 2.129 2.113 2.104 2.106
0.300 2.120 2.131 2.131 2.115 2.106 2.107
0.400 2.124 2.139 2.137 2.119 2.108 2.109
0.500 2.132 2.147 2.141 2.123 2.111 2.112
0.600 2.139 2.156 2.149 2.128 2.114 2.115
0.700 2.148 2.168 2.158 2.133 2.119 2.118
0.800 2.159 2.183 2.167 2.143 2.133 2.124
0.850 2.166 2.198 2.174 2.150 2.143 2.129
0.900 2.180 2.239 2.187 2.164 2.164 2.140
0.925 2.193 2.271 2.202 2.186 2.190 2.157
0.930 2.196 2.278 2.207 2.191 2.198 2.165
0.950 2.220 2.319 2.231 2.217 2.239 2.204
0.960 2.236 2.346 2.244 2.236 2.269 2.221
0.975 2.286 2.428 2.281 2.288 2.339 2.261
0.980 2.316 2.475 2.310 2.314 2.358 2.281
0.990 2.476 2.616 2.394 2.387 2.439 2.330
Table 2 (Cont'd). Cumulative Distributions of Zenith Atmospheric Noise
Temperature at L- and S-Bands for Canberra DSCC, K
CD July August September October November December Minimum Year Maximum
Average
0.000 2.085 2.085 2.085 2.085 2.085 2.085 2.085 2.085 2.085
0.100 2.097 2.097 2.101 2.102 2.109 2.102 2.097 2.105 2.121
0.200 2.100 2.101 2.105 2.107 2.114 2.109 2.100 2.110 2.127
0.250 2.102 2.102 2.107 2.108 2.117 2.112 2.102 2.112 2.129
0.300 2.103 2.103 2.108 2.110 2.119 2.115 2.103 2.114 2.131
0.400 2.105 2.105 2.112 2.113 2.124 2.120 2.105 2.118 2.139
0.500 2.108 2.107 2.115 2.117 2.129 2.125 2.107 2.122 2.147
0.600 2.111 2.110 2.119 2.123 2.135 2.132 2.110 2.128 2.156
0.700 2.115 2.114 2.125 2.131 2.144 2.141 2.114 2.134 2.168
0.800 2.122 2.121 2.133 2.146 2.162 2.157 2.121 2.146 2.183
0.850 2.128 2.128 2.140 2.158 2.179 2.172 2.128 2.155 2.198
0.900 2.138 2.144 2.152 2.181 2.206 2.197 2.138 2.174 2.239
0.925 2.151 2.161 2.164 2.208 2.232 2.219 2.151 2.195 2.271
0.930 2.155 2.166 2.169 2.215 2.239 2.227 2.155 2.200 2.278
0.950 2.171 2.190 2.198 2.262 2.279 2.261 2.171 2.233 2.319
0.960 2.183 2.212 2.220 2.288 2.303 2.278 2.183 2.253 2.346
0.975 2.209 2.285 2.266 2.365 2.392 2.322 2.209 2.310 2.428
0.980 2.223 2.309 2.296 2.414 2.432 2.343 2.223 2.339 2.475
0.990 2.274 2.394 2.423 2.532 2.547 2.412 2.274 2.435 2.616
Table 3. Cumulative Distributions of Zenith Atmospheric Noise Temperature at L-
and S-Bands for Madrid DSCC, K
CD January February March April May June
0.000 2.008 2.008 2.008 2.008 2.008 2.008
0.100 2.014 2.013 2.018 2.019 2.026 2.029
0.200 2.017 2.017 2.022 2.023 2.031 2.034
0.250 2.018 2.018 2.023 2.024 2.032 2.035
0.300 2.020 2.019 2.025 2.026 2.034 2.037
0.400 2.023 2.022 2.028 2.028 2.038 2.041
0.500 2.027 2.025 2.031 2.032 2.041 2.044
0.600 2.032 2.029 2.035 2.036 2.044 2.047
0.700 2.042 2.034 2.041 2.042 2.048 2.051
0.800 2.066 2.042 2.052 2.054 2.057 2.055
0.850 2.092 2.054 2.063 2.066 2.075 2.059
0.900 2.139 2.077 2.088 2.084 2.114 2.065
0.925 2.192 2.102 2.116 2.102 2.155 2.070
0.930 2.201 2.107 2.122 2.106 2.163 2.072
0.950 2.272 2.145 2.157 2.142 2.211 2.085
0.960 2.299 2.167 2.179 2.163 2.237 2.098
0.975 2.361 2.227 2.237 2.211 2.298 2.140
0.980 2.380 2.247 2.259 2.225 2.320 2.169
0.990 2.450 2.324 2.335 2.276 2.394 2.282
Table 3 (Cont'd). Cumulative Distributions of Zenith Atmospheric Noise
Temperature at L- and S-Bands for Madrid DSCC, K
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 2.008 2.008 2.008 2.008 2.008 2.008 2.008 2.008 2.008
0.100 2.032 2.032 2.029 2.023 2.008 2.013 2.008 2.021 2.032
0.200 2.036 2.037 2.034 2.031 2.018 2.018 2.017 2.026 2.037
0.250 2.037 2.038 2.036 2.033 2.020 2.020 2.018 2.028 2.038
0.300 2.039 2.040 2.038 2.036 2.023 2.023 2.019 2.030 2.040
0.400 2.043 2.043 2.042 2.041 2.026 2.027 2.022 2.033 2.043
0.500 2.045 2.047 2.046 2.047 2.030 2.032 2.025 2.037 2.047
0.600 2.048 2.050 2.051 2.054 2.036 2.038 2.029 2.042 2.054
0.700 2.052 2.053 2.055 2.062 2.044 2.049 2.034 2.048 2.062
0.800 2.055 2.058 2.061 2.082 2.058 2.073 2.042 2.059 2.082
0.850 2.057 2.060 2.065 2.105 2.079 2.099 2.054 2.073 2.105
0.900 2.061 2.064 2.072 2.147 2.121 2.142 2.061 2.098 2.147
0.925 2.063 2.067 2.079 2.189 2.164 2.181 2.063 2.123 2.192
0.930 2.064 2.067 2.081 2.197 2.171 2.187 2.064 2.128 2.201
0.950 2.067 2.071 2.095 2.256 2.229 2.235 2.067 2.164 2.272
0.960 2.069 2.074 2.110 2.283 2.253 2.257 2.069 2.182 2.299
0.975 2.077 2.083 2.159 2.350 2.316 2.316 2.077 2.231 2.361
0.980 2.084 2.090 2.196 2.377 2.333 2.334 2.084 2.251 2.380
0.990 2.117 2.119 2.333 2.481 2.400 2.397 2.117 2.326 2.481
Table 4. Cumulative Distributions of Zenith Atmospheric Noise Temperature
at X-Band for Goldstone DSCC, K
CD January February March April May June
0.000 2.135 2.135 2.135 2.135 2.135 2.135
0.100 2.218 2.210 2.220 2.233 2.257 2.246
0.200 2.241 2.238 2.247 2.266 2.297 2.284
0.250 2.249 2.249 2.256 2.276 2.310 2.296
0.300 2.264 2.264 2.268 2.291 2.331 2.315
0.400 2.288 2.286 2.292 2.311 2.372 2.346
0.500 2.317 2.309 2.318 2.333 2.421 2.395
0.600 2.355 2.334 2.342 2.361 2.463 2.464
0.700 2.416 2.376 2.373 2.390 2.510 2.536
0.800 2.506 2.450 2.424 2.426 2.578 2.603
0.850 2.599 2.510 2.455 2.448 2.634 2.647
0.900 2.758 2.634 2.509 2.483 2.728 2.725
0.925 2.956 2.732 2.543 2.507 2.805 2.807
0.930 2.991 2.758 2.549 2.511 2.825 2.817
0.950 3.277 2.911 2.607 2.547 3.020 2.912
0.960 3.475 3.039 2.678 2.576 3.113 3.002
0.975 4.041 3.324 2.885 2.666 3.381 3.262
0.980 4.265 3.452 3.010 2.755 3.462 3.395
0.990 5.160 3.944 3.553 3.147 3.824 3.943
Table 4 (Cont'd). Cumulative Distributions of Zenith Atmospheric Noise
Temperature at X-Band for Goldstone DSCC, K
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 2.135 2.135 2.135 2.135 2.135 2.135 2.135 2.135 2.135
0.100 2.294 2.306 2.332 2.268 2.227 2.207 2.207 2.251 2.332
0.200 2.365 2.375 2.374 2.303 2.262 2.239 2.238 2.291 2.375
0.250 2.387 2.402 2.393 2.315 2.274 2.248 2.248 2.305 2.402
0.300 2.422 2.447 2.425 2.336 2.292 2.263 2.263 2.327 2.447
0.400 2.474 2.512 2.481 2.375 2.325 2.284 2.284 2.362 2.512
0.500 2.545 2.592 2.553 2.408 2.366 2.307 2.307 2.405 2.592
0.600 2.630 2.652 2.612 2.444 2.426 2.335 2.334 2.451 2.652
0.700 2.739 2.695 2.690 2.488 2.487 2.382 2.373 2.507 2.739
0.800 2.830 2.760 2.766 2.552 2.556 2.460 2.424 2.576 2.830
0.850 2.878 2.805 2.813 2.600 2.603 2.541 2.448 2.628 2.878
0.900 2.946 2.876 2.915 2.681 2.680 2.676 2.483 2.718 2.946
0.925 2.996 2.924 2.981 2.725 2.726 2.773 2.507 2.790 2.996
0.930 3.009 2.934 2.989 2.732 2.731 2.801 2.511 2.804 3.009
0.950 3.074 3.019 3.066 2.793 2.777 3.048 2.547 2.921 3.277
0.960 3.126 3.078 3.141 2.850 2.824 3.208 2.576 3.009 3.475
0.975 3.295 3.246 3.356 3.022 2.963 3.631 2.666 3.256 4.041
0.980 3.404 3.272 3.577 3.120 3.098 3.819 2.755 3.386 4.265
0.990 3.912 3.377 4.578 3.585 3.663 4.570 3.147 3.938 5.160
Table 5. Cumulative Distributions of Zenith Atmospheric Noise Temperature
at X-Band for Canberra DSCC, K
CD January February March April May June
0.000 2.327 2.327 2.327 2.327 2.327 2.327
0.100 2.631 2.741 2.815 2.607 2.531 2.513
0.200 2.725 2.841 2.895 2.679 2.568 2.594
0.250 2.763 2.892 2.924 2.705 2.587 2.612
0.300 2.792 2.948 2.953 2.732 2.607 2.626
0.400 2.853 3.057 3.021 2.783 2.641 2.656
0.500 2.955 3.162 3.087 2.843 2.678 2.691
0.600 3.057 3.287 3.187 2.902 2.714 2.730
0.700 3.177 3.439 3.303 2.978 2.782 2.777
0.800 3.321 3.641 3.433 3.101 2.974 2.849
0.850 3.419 3.848 3.527 3.198 3.112 2.918
0.900 3.604 4.396 3.704 3.385 3.387 3.063
0.925 3.780 4.829 3.898 3.687 3.738 3.299
0.930 3.821 4.921 3.963 3.757 3.848 3.401
0.950 4.138 5.483 4.287 4.109 4.399 3.929
0.960 4.361 5.843 4.465 4.366 4.802 4.164
0.975 5.027 6.950 4.966 5.062 5.740 4.695
0.980 5.435 7.580 5.350 5.412 5.997 4.965
0.990 7.589 9.469 6.492 6.392 7.091 5.622
Table 5 (Cont'd). Cumulative Distributions of Zenith Atmospheric Noise
Temperature at X-Band for Canberra DSCC, K
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 2.327 2.327 2.327 2.327 2.327 2.327 2.327 2.327 2.327
0.100 2.485 2.491 2.548 2.550 2.649 2.562 2.485 2.594 2.815
0.200 2.532 2.539 2.600 2.617 2.723 2.648 2.532 2.663 2.895
0.250 2.551 2.556 2.621 2.640 2.755 2.693 2.551 2.692 2.924
0.300 2.567 2.570 2.643 2.662 2.790 2.731 2.567 2.718 2.953
0.400 2.598 2.598 2.688 2.705 2.858 2.801 2.598 2.772 3.057
0.500 2.636 2.628 2.732 2.760 2.924 2.871 2.628 2.831 3.162
0.600 2.676 2.669 2.785 2.837 3.002 2.958 2.669 2.900 3.287
0.700 2.725 2.723 2.863 2.942 3.117 3.079 2.723 2.992 3.439
0.800 2.823 2.807 2.966 3.153 3.362 3.298 2.807 3.144 3.641
0.850 2.907 2.900 3.062 3.310 3.594 3.501 2.900 3.275 3.848
0.900 3.045 3.125 3.232 3.625 3.955 3.834 3.045 3.530 4.396
0.925 3.222 3.351 3.396 3.982 4.312 4.131 3.222 3.802 4.829
0.930 3.265 3.413 3.464 4.077 4.403 4.234 3.265 3.881 4.921
0.950 3.484 3.741 3.852 4.704 4.938 4.690 3.484 4.313 5.483
0.960 3.649 4.037 4.146 5.064 5.266 4.920 3.649 4.590 5.843
0.975 3.999 5.018 4.766 6.097 6.453 5.522 3.999 5.358 6.950
0.980 4.187 5.340 5.165 6.757 7.003 5.794 4.187 5.749 7.580
0.990 4.874 6.481 6.882 8.346 8.552 6.732 4.874 7.043 9.469
Table 6. Cumulative Distributions of Zenith Atmospheric Noise Temperature
at X-Band for Madrid DSCC, K
CD January February March April May June
0.000 2.239 2.239 2.239 2.239 2.239 2.239
0.100 2.314 2.310 2.378 2.386 2.483 2.522
0.200 2.364 2.358 2.425 2.442 2.545 2.585
0.250 2.379 2.372 2.442 2.456 2.564 2.604
0.300 2.401 2.392 2.466 2.475 2.592 2.634
0.400 2.439 2.423 2.502 2.512 2.639 2.677
0.500 2.492 2.470 2.551 2.561 2.679 2.722
0.600 2.565 2.524 2.605 2.620 2.723 2.767
0.700 2.695 2.588 2.684 2.700 2.775 2.816
0.800 3.013 2.697 2.829 2.859 2.897 2.877
0.850 3.365 2.855 2.984 3.019 3.137 2.922
0.900 4.006 3.167 3.322 3.264 3.662 3.004
0.925 4.714 3.499 3.697 3.506 4.213 3.074
0.930 4.835 3.567 3.773 3.562 4.320 3.095
0.950 5.796 4.089 4.239 4.047 4.971 3.280
0.960 6.151 4.379 4.536 4.328 5.324 3.452
0.975 6.990 5.186 5.323 4.965 6.142 4.021
0.980 7.242 5.454 5.623 5.155 6.438 4.411
0.990 8.190 6.491 6.646 5.847 7.435 5.921
Table 6 (Cont'd). Cumulative Distributions of Zenith Atmospheric Noise
Temperature at X-Band for Madrid DSCC, K
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 2.239 2.239 2.239 2.239 2.239 2.239 2.239 2.239 2.239
0.100 2.560 2.563 2.519 2.442 2.235 2.312 2.235 2.419 2.563
0.200 2.618 2.626 2.588 2.542 2.373 2.375 2.358 2.487 2.626
0.250 2.636 2.645 2.611 2.571 2.397 2.398 2.372 2.506 2.645
0.300 2.662 2.674 2.646 2.616 2.436 2.436 2.392 2.536 2.674
0.400 2.704 2.717 2.699 2.688 2.483 2.500 2.423 2.582 2.717
0.500 2.744 2.760 2.754 2.765 2.538 2.565 2.470 2.633 2.765
0.600 2.784 2.806 2.814 2.855 2.615 2.649 2.524 2.694 2.855
0.700 2.825 2.851 2.874 2.972 2.717 2.794 2.588 2.774 2.972
0.800 2.873 2.910 2.951 3.241 2.910 3.114 2.697 2.931 3.241
0.850 2.902 2.943 3.002 3.544 3.196 3.461 2.855 3.111 3.544
0.900 2.948 2.997 3.095 4.108 3.757 4.037 2.948 3.447 4.108
0.925 2.981 3.029 3.196 4.674 4.342 4.572 2.981 3.791 4.714
0.930 2.987 3.036 3.218 4.779 4.438 4.650 2.987 3.855 4.835
0.950 3.034 3.086 3.414 5.576 5.212 5.289 3.034 4.336 5.796
0.960 3.064 3.125 3.614 5.940 5.540 5.592 3.064 4.587 6.151
0.975 3.168 3.253 4.272 6.842 6.389 6.380 3.168 5.244 6.990
0.980 3.257 3.344 4.769 7.208 6.619 6.624 3.257 5.512 7.242
0.990 3.702 3.734 6.609 8.606 7.512 7.475 3.702 6.514 8.606
Table 7. Cumulative Distributions of
Zenith Atmospheric Noise Temperature at Ka-Band for Goldstone DSCC, K
CD January February March April May June
0.000 6.700 6.700 6.700 6.700 6.700 6.700
0.100 7.904 7.785 7.925 8.119 8.463 8.302
0.200 8.227 8.181 8.321 8.594 9.041 8.856
0.250 8.354 8.342 8.441 8.731 9.233 9.031
0.300 8.564 8.563 8.626 8.948 9.531 9.304
0.400 8.915 8.888 8.967 9.237 10.127 9.748
0.500 9.325 9.218 9.346 9.563 10.837 10.450
0.600 9.870 9.575 9.688 9.962 11.441 11.447
0.700 10.764 10.181 10.134 10.383 12.115 12.488
0.800 12.058 11.252 10.868 10.909 13.100 13.459
0.850 13.395 12.119 11.316 11.226 13.912 14.098
0.900 15.703 13.903 12.100 11.726 15.260 15.217
0.925 18.556 15.328 12.600 12.070 16.383 16.399
0.930 19.068 15.702 12.683 12.133 16.670 16.548
0.950 23.198 17.912 13.523 12.651 19.479 17.919
0.960 26.054 19.756 14.550 13.068 20.820 19.226
0.975 34.229 23.875 17.527 14.366 24.702 22.976
0.980 37.463 25.724 19.338 15.656 25.866 24.904
0.990 50.394 32.834 27.182 21.314 31.090 32.814
Table 7 (Cont'd). Cumulative Distributions of Zenith Atmospheric Noise
Temperature at Ka-Band for Goldstone DSCC, K
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 6.700 6.700 6.700 6.700 6.700 6.700 6.700 6.700 6.700
0.100 8.999 9.167 9.539 8.617 8.028 7.746 7.746 8.383 9.539
0.200 10.021 10.163 10.153 9.130 8.529 8.197 8.181 8.951 10.163
0.250 10.341 10.559 10.424 9.301 8.701 8.337 8.337 9.150 10.559
0.300 10.848 11.213 10.890 9.606 8.969 8.549 8.549 9.468 11.213
0.400 11.592 12.143 11.701 10.170 9.444 8.854 8.854 9.982 12.143
0.500 12.618 13.303 12.736 10.649 10.037 9.186 9.186 10.606 13.303
0.600 13.848 14.174 13.595 11.156 10.899 9.585 9.575 11.270 14.174
0.700 15.424 14.787 14.714 11.805 11.782 10.264 10.134 12.070 15.424
0.800 16.742 15.727 15.812 12.722 12.786 11.389 10.868 13.069 16.742
0.850 17.426 16.371 16.487 13.410 13.465 12.566 11.226 13.816 17.426
0.900 18.419 17.398 17.964 14.581 14.576 14.521 11.726 15.114 18.419
0.925 19.131 18.090 18.919 15.220 15.229 15.921 12.070 16.154 19.131
0.930 19.323 18.247 19.040 15.317 15.304 16.325 12.133 16.363 19.323
0.950 20.260 19.474 20.152 16.204 15.976 19.884 12.651 18.053 23.198
0.960 21.008 20.321 21.234 17.020 16.651 22.199 13.068 19.326 26.054
0.975 23.451 22.752 24.331 19.512 18.657 28.306 14.366 22.890 34.229
0.980 25.032 23.123 27.535 20.927 20.607 31.025 15.656 24.767 37.463
0.990 32.362 24.643 41.986 27.647 28.774 41.871 21.314 32.743 50.394
Table 8. Cumulative Distributions of Zenith Atmospheric Noise Temperature
at Ka-Band for Canberra DSCC, K
CD January February March April May June
0.000 7.274 7.274 7.274 7.274 7.274 7.274
0.100 11.671 13.259 14.320 11.313 10.215 9.957
0.200 13.019 14.694 15.485 12.360 10.760 11.133
0.250 13.570 15.432 15.895 12.740 11.030 11.390
0.300 13.996 16.240 16.314 13.120 11.320 11.594
0.400 14.873 17.813 17.305 13.865 11.810 12.023
0.500 16.347 19.333 18.255 14.730 12.340 12.530
0.600 17.820 21.135 19.690 15.580 12.870 13.093
0.700 19.554 23.330 21.375 16.675 13.844 13.780
0.800 21.631 26.251 23.250 18.455 16.624 14.809
0.850 23.048 29.237 24.613 19.853 18.614 15.805
0.900 25.721 37.155 27.169 22.553 22.586 17.897
0.925 28.258 43.415 29.972 26.919 27.655 21.311
0.930 28.846 44.748 30.911 27.935 29.242 22.786
0.950 33.438 52.852 35.590 33.007 37.206 30.415
0.960 36.657 58.057 38.148 36.725 43.020 33.801
0.975 46.274 74.052 45.395 46.781 56.575 41.481
0.980 52.169 83.148 50.943 51.827 60.285 45.372
0.990 83.280 110.437 67.432 65.986 76.082 54.859
Table 8 (Cont'd). Cumulative Distributions of Zenith Atmospheric Noise
Temperature at Ka-Band for Canberra DSCC, K
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 7.274 7.274 7.274 7.274 7.274 7.274 7.274 7.274 7.274
0.100 9.563 9.638 10.470 10.500 11.923 10.670 9.563 11.125 14.320
0.200 10.235 10.333 11.213 11.467 12.993 11.917 10.235 12.134 15.485
0.250 10.505 10.580 11.523 11.800 13.452 12.553 10.505 12.539 15.895
0.300 10.743 10.789 11.840 12.113 13.957 13.103 10.743 12.927 16.314
0.400 11.188 11.190 12.493 12.737 14.940 14.117 11.188 13.696 17.813
0.500 11.730 11.619 13.128 13.533 15.893 15.133 11.619 14.548 19.333
0.600 12.313 12.215 13.887 14.633 17.030 16.381 12.215 15.554 21.135
0.700 13.028 12.988 15.017 16.155 18.682 18.143 12.988 16.881 23.330
0.800 14.442 14.200 16.511 19.203 22.224 21.303 14.200 19.075 26.251
0.850 15.655 15.547 17.889 21.470 25.576 24.236 15.547 20.962 29.237
0.900 17.645 18.804 20.349 26.021 30.782 29.038 17.645 24.643 37.155
0.925 20.202 22.063 22.720 31.181 35.946 33.327 20.202 28.581 43.415
0.930 20.824 22.967 23.690 32.545 37.255 34.818 20.824 29.714 44.748
0.950 23.988 27.691 29.298 41.607 44.979 41.402 23.988 35.956 52.852
0.960 26.372 31.975 33.550 46.812 49.729 44.727 26.372 39.964 58.057
0.975 31.422 46.147 42.500 61.731 66.869 53.428 31.422 51.054 74.052
0.980 34.134 50.786 48.262 71.255 74.809 57.345 34.134 56.695 83.148
0.990 44.061 67.266 73.060 94.217 97.186 70.896 44.061 75.397 110.437
Table 9. Cumulative Distributions of Zenith Atmospheric Noise Temperature
at Ka-Band for Madrid DSCC, K
CD January February March April May June
0.000 7.000 7.000 7.000 7.000 7.000 7.000
0.100 8.081 8.027 9.008 9.129 10.527 11.095
0.200 8.807 8.715 9.680 9.934 11.424 12.001
0.250 9.020 8.918 9.928 10.128 11.700 12.279
0.300 9.345 9.209 10.275 10.413 12.094 12.701
0.400 9.893 9.661 10.801 10.941 12.778 13.321
0.500 10.660 10.343 11.505 11.649 13.349 13.978
0.600 11.705 11.122 12.284 12.505 13.985 14.626
0.700 13.588 12.034 13.426 13.658 14.740 15.331
0.800 18.184 13.617 15.527 15.956 16.508 16.218
0.850 23.264 15.894 17.764 18.261 19.967 16.865
0.900 32.518 20.404 22.635 21.803 27.555 18.056
0.925 42.747 25.199 28.054 25.304 35.506 19.059
0.930 44.501 26.176 29.154 26.115 37.057 19.361
0.950 58.380 33.714 35.887 33.118 46.457 22.041
0.960 63.503 37.904 40.178 37.171 51.554 24.514
0.975 75.622 49.567 51.540 46.376 63.371 32.733
0.980 79.259 53.436 55.884 49.123 67.655 38.373
0.990 92.957 68.414 70.648 59.108 82.045 60.183
Table 9 (Cont'd). Cumulative Distributions of Zenith Atmospheric Noise
Temperature at Ka-Band for Madrid DSCC, K
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 7.000 7.000 7.000 7.000 7.000 7.000 7.000 7.000 7.000
0.100 11.629 11.685 11.048 9.928 6.945 8.053 6.945 9.596 11.685
0.200 12.472 12.584 12.045 11.382 8.940 8.957 8.715 10.578 12.584
0.250 12.729 12.868 12.368 11.802 9.280 9.297 8.918 10.860 12.868
0.300 13.108 13.287 12.877 12.451 9.852 9.845 9.209 11.288 13.287
0.400 13.719 13.901 13.650 13.489 10.522 10.775 9.661 11.954 13.901
0.500 14.290 14.523 14.437 14.599 11.318 11.708 10.343 12.697 14.599
0.600 14.866 15.183 15.311 15.893 12.425 12.920 11.122 13.569 15.893
0.700 15.470 15.844 16.170 17.581 13.910 15.023 12.034 14.731 17.581
0.800 16.164 16.691 17.282 21.475 16.699 19.634 13.617 16.996 21.475
0.850 16.577 17.169 18.017 25.853 20.829 24.646 15.894 19.592 25.853
0.900 17.245 17.946 19.369 33.998 28.929 32.965 17.245 24.452 33.998
0.925 17.715 18.413 20.820 42.171 37.379 40.700 17.715 29.422 42.747
0.930 17.803 18.505 21.142 43.694 38.756 41.828 17.803 30.341 44.501
0.950 18.487 19.229 23.978 55.198 49.934 51.055 18.487 37.290 58.380
0.960 18.918 19.803 26.856 60.459 54.681 55.436 18.918 40.915 63.503
0.975 20.416 21.652 36.364 73.478 66.936 66.807 20.416 50.405 75.622
0.980 21.709 22.960 43.548 78.764 70.263 70.341 21.709 54.276 79.259
0.990 28.129 28.596 70.125 98.968 83.164 82.632 28.129 68.747 98.968
Table 10. Cumulative Distributions of Zenith Atmospheric Attenuation at L- and S-
Bands for Goldstone DSCC, dB
CD January February March April May June
0.000 0.033 0.033 0.033 0.033 0.033 0.033
0.100 0.033 0.033 0.033 0.033 0.033 0.033
0.200 0.032 0.032 0.032 0.032 0.032 0.032
0.250 0.032 0.032 0.032 0.032 0.032 0.032
0.300 0.032 0.032 0.032 0.032 0.032 0.032
0.400 0.032 0.032 0.032 0.032 0.032 0.032
0.500 0.031 0.031 0.031 0.031 0.032 0.032
0.600 0.031 0.031 0.031 0.031 0.031 0.031
0.700 0.031 0.031 0.031 0.031 0.031 0.031
0.800 0.031 0.031 0.031 0.031 0.031 0.031
0.850 0.031 0.031 0.031 0.031 0.031 0.031
0.900 0.031 0.031 0.031 0.031 0.031 0.031
0.925 0.031 0.031 0.031 0.030 0.031 0.031
0.930 0.031 0.031 0.031 0.030 0.031 0.031
0.950 0.031 0.031 0.031 0.030 0.031 0.031
0.960 0.032 0.031 0.031 0.030 0.031 0.031
0.975 0.032 0.031 0.031 0.031 0.031 0.031
0.980 0.032 0.031 0.031 0.031 0.031 0.031
0.990 0.033 0.032 0.032 0.031 0.032 0.032
Table 10 (Cont'd). Cumulative Distributions of Zenith Atmospheric Attenuation at
L- and S-Bands for Goldstone DSCC, dB
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 0.033 0.033 0.033 0.033 0.033 0.033 0.033 0.033 0.033
0.100 0.033 0.033 0.033 0.033 0.033 0.033 0.033 0.033 0.033
0.200 0.032 0.032 0.032 0.032 0.032 0.032 0.032 0.032 0.032
0.250 0.032 0.032 0.032 0.032 0.032 0.032 0.032 0.032 0.032
0.300 0.032 0.032 0.032 0.032 0.032 0.032 0.032 0.032 0.032
0.400 0.032 0.032 0.032 0.032 0.032 0.032 0.032 0.032 0.032
0.500 0.032 0.032 0.032 0.032 0.032 0.031 0.031 0.032 0.032
0.600 0.032 0.032 0.032 0.031 0.031 0.031 0.031 0.031 0.032
0.700 0.031 0.031 0.031 0.031 0.031 0.031 0.031 0.031 0.031
0.800 0.031 0.031 0.031 0.031 0.031 0.031 0.031 0.031 0.031
0.850 0.031 0.031 0.031 0.031 0.031 0.031 0.031 0.031 0.031
0.900 0.031 0.031 0.031 0.031 0.031 0.031 0.031 0.031 0.031
0.925 0.031 0.031 0.031 0.031 0.031 0.031 0.030 0.031 0.031
0.930 0.031 0.031 0.031 0.031 0.031 0.031 0.030 0.031 0.031
0.950 0.031 0.031 0.031 0.031 0.031 0.031 0.030 0.031 0.031
0.960 0.031 0.031 0.031 0.031 0.031 0.031 0.030 0.031 0.032
0.975 0.031 0.031 0.031 0.031 0.031 0.032 0.031 0.031 0.032
0.980 0.031 0.031 0.032 0.031 0.031 0.032 0.031 0.031 0.032
0.990 0.032 0.031 0.033 0.032 0.032 0.033 0.031 0.032 0.033
Table 11. Cumulative Distributions of Zenith Atmospheric Attenuation at L- and S-
Bands for Canberra DSCC, dB
CD January February March April May June
0.000 0.036 0.036 0.036 0.036 0.036 0.036
0.100 0.036 0.036 0.036 0.036 0.036 0.036
0.200 0.035 0.036 0.036 0.035 0.035 0.035
0.250 0.035 0.036 0.036 0.035 0.035 0.035
0.300 0.035 0.035 0.035 0.035 0.035 0.035
0.400 0.035 0.035 0.035 0.035 0.035 0.035
0.500 0.035 0.035 0.035 0.035 0.034 0.034
0.600 0.035 0.035 0.035 0.034 0.034 0.034
0.700 0.034 0.035 0.035 0.034 0.034 0.034
0.800 0.034 0.035 0.034 0.034 0.034 0.034
0.850 0.034 0.035 0.034 0.034 0.034 0.034
0.900 0.034 0.035 0.034 0.034 0.034 0.034
0.925 0.034 0.036 0.035 0.034 0.034 0.034
0.930 0.034 0.036 0.035 0.034 0.034 0.034
0.950 0.035 0.036 0.035 0.035 0.035 0.034
0.960 0.035 0.037 0.035 0.035 0.035 0.035
0.975 0.036 0.038 0.036 0.036 0.037 0.035
0.980 0.036 0.039 0.036 0.036 0.037 0.036
0.990 0.039 0.041 0.037 0.037 0.038 0.036
Table 11 (Cont'd). Cumulative Distributions of Zenith Atmospheric Attenuation at
L- and S-Bands for Canberra DSCC, dB
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 0.036 0.036 0.036 0.036 0.036 0.036 0.036 0.036 0.036
0.100 0.036 0.036 0.036 0.036 0.036 0.036 0.036 0.036 0.036
0.200 0.035 0.035 0.035 0.035 0.035 0.035 0.035 0.035 0.036
0.250 0.035 0.035 0.035 0.035 0.035 0.035 0.035 0.035 0.036
0.300 0.035 0.035 0.035 0.035 0.035 0.035 0.035 0.035 0.035
0.400 0.035 0.035 0.035 0.035 0.035 0.035 0.035 0.035 0.035
0.500 0.034 0.034 0.034 0.035 0.035 0.035 0.034 0.035 0.035
0.600 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.035
0.700 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.035
0.800 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.035
0.850 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.035
0.900 0.034 0.034 0.034 0.034 0.035 0.035 0.034 0.034 0.035
0.925 0.034 0.034 0.034 0.035 0.035 0.035 0.034 0.034 0.036
0.930 0.034 0.034 0.034 0.035 0.035 0.035 0.034 0.034 0.036
0.950 0.034 0.034 0.034 0.035 0.036 0.035 0.034 0.035 0.036
0.960 0.034 0.035 0.035 0.036 0.036 0.036 0.034 0.035 0.037
0.975 0.034 0.036 0.035 0.037 0.037 0.036 0.034 0.036 0.038
0.980 0.035 0.036 0.036 0.038 0.038 0.037 0.035 0.037 0.039
0.990 0.035 0.037 0.038 0.039 0.040 0.038 0.035 0.038 0.041
Table 12. Cumulative Distributions of Zenith Atmospheric Attenuation at
L- and S-Bands for Madrid DSCC, dB
CD January February March April May June
0.000 0.034 0.034 0.034 0.034 0.034 0.034
0.100 0.034 0.034 0.034 0.034 0.034 0.034
0.200 0.034 0.034 0.034 0.034 0.034 0.034
0.250 0.034 0.034 0.034 0.034 0.034 0.034
0.300 0.034 0.034 0.034 0.034 0.034 0.034
0.400 0.033 0.033 0.033 0.033 0.034 0.034
0.500 0.033 0.033 0.033 0.033 0.033 0.033
0.600 0.033 0.033 0.033 0.033 0.033 0.033
0.700 0.033 0.033 0.033 0.033 0.033 0.033
0.800 0.033 0.032 0.033 0.033 0.033 0.033
0.850 0.033 0.032 0.033 0.033 0.033 0.032
0.900 0.034 0.033 0.033 0.033 0.033 0.032
0.925 0.034 0.033 0.033 0.033 0.034 0.032
0.930 0.034 0.033 0.033 0.033 0.034 0.032
0.950 0.036 0.034 0.034 0.034 0.035 0.033
0.960 0.036 0.034 0.034 0.034 0.035 0.033
0.975 0.037 0.035 0.035 0.034 0.036 0.033
0.980 0.037 0.035 0.035 0.035 0.036 0.034
0.990 0.038 0.036 0.036 0.035 0.037 0.036
Table 12 (Cont'd). Cumulative Distributions of Zenith Atmospheric Attenuation at
L- and S-Bands for Madrid DSCC, dB
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.034
0.100 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.034
0.200 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.034
0.250 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.034
0.300 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.034 0.034
0.400 0.034 0.034 0.034 0.034 0.033 0.033 0.033 0.033 0.034
0.500 0.033 0.033 0.033 0.033 0.033 0.033 0.033 0.033 0.033
0.600 0.033 0.033 0.033 0.033 0.033 0.033 0.033 0.033 0.033
0.700 0.033 0.033 0.033 0.033 0.033 0.033 0.033 0.033 0.033
0.800 0.033 0.033 0.033 0.033 0.033 0.033 0.032 0.033 0.033
0.850 0.032 0.033 0.033 0.033 0.033 0.033 0.032 0.033 0.033
0.900 0.032 0.032 0.033 0.034 0.033 0.034 0.032 0.033 0.034
0.925 0.032 0.032 0.033 0.034 0.034 0.034 0.032 0.033 0.034
0.930 0.032 0.032 0.033 0.034 0.034 0.034 0.032 0.033 0.034
0.950 0.032 0.032 0.033 0.035 0.035 0.035 0.032 0.034 0.036
0.960 0.032 0.032 0.033 0.036 0.035 0.035 0.032 0.034 0.036
0.975 0.032 0.033 0.034 0.037 0.036 0.036 0.032 0.035 0.037
0.980 0.032 0.033 0.034 0.037 0.036 0.036 0.032 0.035 0.037
0.990 0.033 0.033 0.036 0.039 0.037 0.037 0.033 0.036 0.039
Table 13. Cumulative Distributions of Zenith Atmospheric Attenuation at X-Band
for Goldstone DSCC, dB
CD January February March April May June
0.000 0.037 0.037 0.037 0.037 0.037 0.037
0.100 0.038 0.037 0.038 0.038 0.038 0.038
0.200 0.038 0.038 0.038 0.038 0.039 0.038
0.250 0.038 0.038 0.038 0.038 0.039 0.038
0.300 0.038 0.038 0.038 0.038 0.039 0.038
0.400 0.038 0.038 0.038 0.038 0.039 0.039
0.500 0.038 0.038 0.038 0.038 0.039 0.039
0.600 0.038 0.038 0.038 0.038 0.040 0.040
0.700 0.039 0.038 0.038 0.038 0.040 0.041
0.800 0.040 0.039 0.038 0.038 0.041 0.041
0.850 0.041 0.040 0.039 0.039 0.042 0.042
0.900 0.043 0.041 0.039 0.039 0.043 0.043
0.925 0.046 0.043 0.040 0.039 0.044 0.044
0.930 0.047 0.043 0.040 0.039 0.044 0.044
0.950 0.051 0.046 0.041 0.040 0.047 0.046
0.960 0.054 0.048 0.042 0.040 0.049 0.047
0.975 0.063 0.052 0.045 0.042 0.053 0.051
0.980 0.067 0.054 0.047 0.043 0.054 0.053
0.990 0.081 0.062 0.056 0.049 0.060 0.062
Table 13 (Cont'd). Cumulative Distributions of Zenith Atmospheric Attenuation at
X-Band for Goldstone DSCC, dB
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 0.037 0.037 0.037 0.037 0.037 0.037 0.037 0.037 0.037
0.100 0.039 0.039 0.040 0.038 0.038 0.037 0.037 0.038 0.040
0.200 0.040 0.040 0.040 0.039 0.038 0.038 0.038 0.038 0.040
0.250 0.040 0.040 0.040 0.039 0.038 0.038 0.038 0.038 0.040
0.300 0.040 0.041 0.040 0.039 0.038 0.038 0.038 0.039 0.041
0.400 0.041 0.041 0.041 0.039 0.038 0.038 0.038 0.039 0.041
0.500 0.042 0.042 0.042 0.039 0.039 0.038 0.038 0.039 0.042
0.600 0.043 0.043 0.042 0.039 0.039 0.038 0.038 0.040 0.043
0.700 0.044 0.043 0.043 0.040 0.040 0.038 0.038 0.040 0.044
0.800 0.045 0.044 0.044 0.040 0.041 0.039 0.038 0.041 0.045
0.850 0.045 0.044 0.044 0.041 0.041 0.040 0.039 0.042 0.045
0.900 0.046 0.045 0.046 0.042 0.042 0.042 0.039 0.043 0.046
0.925 0.047 0.046 0.047 0.043 0.043 0.044 0.039 0.044 0.047
0.930 0.047 0.046 0.047 0.043 0.043 0.044 0.039 0.044 0.047
0.950 0.048 0.047 0.048 0.044 0.043 0.048 0.040 0.046 0.051
0.960 0.049 0.048 0.049 0.045 0.044 0.050 0.040 0.047 0.054
0.975 0.052 0.051 0.052 0.047 0.046 0.057 0.042 0.051 0.063
0.980 0.053 0.051 0.056 0.049 0.048 0.060 0.043 0.053 0.067
0.990 0.061 0.053 0.072 0.056 0.057 0.072 0.049 0.062 0.081
Table 14. Cumulative Distributions of Zenith Atmospheric Attenuation at X-Band
for Canberra DSCC, dB
CD January February March April May June
0.000 0.040 0.040 0.040 0.040 0.040 0.040
0.100 0.045 0.046 0.048 0.044 0.043 0.043
0.200 0.046 0.048 0.049 0.045 0.043 0.044
0.250 0.046 0.048 0.049 0.045 0.043 0.044
0.300 0.046 0.049 0.049 0.045 0.043 0.044
0.400 0.047 0.050 0.050 0.046 0.043 0.044
0.500 0.048 0.052 0.050 0.046 0.044 0.044
0.600 0.049 0.053 0.052 0.047 0.044 0.044
0.700 0.051 0.055 0.053 0.048 0.045 0.044
0.800 0.053 0.058 0.055 0.049 0.047 0.045
0.850 0.054 0.061 0.056 0.051 0.049 0.046
0.900 0.057 0.069 0.058 0.053 0.053 0.048
0.925 0.059 0.076 0.061 0.058 0.059 0.052
0.930 0.060 0.078 0.062 0.059 0.060 0.053
0.950 0.065 0.086 0.067 0.064 0.069 0.062
0.960 0.068 0.092 0.070 0.068 0.075 0.065
0.975 0.079 0.109 0.078 0.079 0.090 0.074
0.980 0.085 0.119 0.084 0.085 0.094 0.078
0.990 0.119 0.150 0.102 0.100 0.112 0.088
Table 14 (Cont'd). Cumulative Distributions of Zenith Atmospheric Attenuation at
X-Band for Canberra DSCC, dB
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 0.040 0.040 0.040 0.040 0.040 0.040 0.040 0.040 0.040
0.100 0.042 0.042 0.043 0.043 0.045 0.043 0.042 0.044 0.048
0.200 0.043 0.043 0.044 0.044 0.046 0.044 0.043 0.045 0.049
0.250 0.043 0.043 0.044 0.044 0.046 0.045 0.043 0.045 0.049
0.300 0.043 0.043 0.044 0.044 0.046 0.045 0.043 0.045 0.049
0.400 0.043 0.043 0.044 0.045 0.047 0.046 0.043 0.046 0.050
0.500 0.043 0.043 0.045 0.045 0.048 0.047 0.043 0.046 0.052
0.600 0.043 0.043 0.045 0.046 0.049 0.048 0.043 0.047 0.053
0.700 0.044 0.044 0.046 0.047 0.050 0.049 0.044 0.048 0.055
0.800 0.045 0.045 0.047 0.050 0.053 0.052 0.045 0.050 0.058
0.850 0.046 0.046 0.048 0.052 0.057 0.055 0.046 0.052 0.061
0.900 0.048 0.049 0.051 0.057 0.062 0.060 0.048 0.056 0.069
0.925 0.051 0.053 0.053 0.063 0.068 0.065 0.051 0.060 0.076
0.930 0.051 0.054 0.054 0.064 0.069 0.067 0.051 0.061 0.078
0.950 0.055 0.059 0.060 0.074 0.078 0.074 0.055 0.068 0.086
0.960 0.057 0.063 0.065 0.080 0.083 0.077 0.057 0.072 0.092
0.975 0.063 0.079 0.075 0.096 0.101 0.087 0.063 0.084 0.109
0.980 0.066 0.084 0.081 0.106 0.110 0.091 0.066 0.090 0.119
0.990 0.076 0.102 0.108 0.132 0.135 0.106 0.076 0.111 0.150
Table 15. Cumulative Distributions of Zenith Atmospheric Attenuation at X-Band
for Madrid DSCC, dB
CD January February March April May June
0.000 0.038 0.038 0.038 0.038 0.038 0.038
0.100 0.039 0.039 0.040 0.040 0.042 0.043
0.200 0.040 0.040 0.041 0.041 0.043 0.043
0.250 0.040 0.040 0.041 0.041 0.043 0.044
0.300 0.040 0.040 0.041 0.041 0.043 0.044
0.400 0.040 0.040 0.041 0.041 0.043 0.044
0.500 0.041 0.040 0.042 0.042 0.044 0.044
0.600 0.041 0.041 0.042 0.042 0.044 0.045
0.700 0.043 0.041 0.043 0.043 0.044 0.045
0.800 0.048 0.043 0.045 0.045 0.046 0.046
0.850 0.053 0.045 0.047 0.048 0.050 0.046
0.900 0.063 0.050 0.052 0.051 0.058 0.047
0.925 0.074 0.055 0.058 0.055 0.066 0.048
0.930 0.076 0.056 0.059 0.056 0.068 0.049
0.950 0.091 0.064 0.067 0.064 0.078 0.051
0.960 0.097 0.069 0.071 0.068 0.084 0.054
0.975 0.110 0.081 0.084 0.078 0.097 0.063
0.980 0.114 0.086 0.088 0.081 0.101 0.069
0.990 0.129 0.102 0.104 0.092 0.117 0.093
Table 15 (Cont'd). Cumulative Distributions of Zenith Atmospheric Attenuation at
X-Band for Madrid DSCC, dB
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 0.038 0.038 0.038 0.038 0.038 0.038 0.038 0.038 0.038
0.100 0.043 0.043 0.043 0.041 0.038 0.039 0.038 0.041 0.043
0.200 0.044 0.044 0.043 0.043 0.040 0.040 0.040 0.042 0.044
0.250 0.044 0.044 0.044 0.043 0.040 0.040 0.040 0.042 0.044
0.300 0.044 0.044 0.044 0.044 0.040 0.040 0.040 0.042 0.044
0.400 0.045 0.045 0.044 0.044 0.041 0.041 0.040 0.043 0.045
0.500 0.045 0.045 0.045 0.045 0.041 0.042 0.040 0.043 0.045
0.600 0.045 0.045 0.046 0.046 0.042 0.043 0.041 0.044 0.046
0.700 0.045 0.046 0.046 0.048 0.044 0.045 0.041 0.044 0.048
0.800 0.046 0.046 0.047 0.051 0.046 0.049 0.043 0.047 0.051
0.850 0.046 0.047 0.047 0.056 0.051 0.055 0.045 0.049 0.056
0.900 0.046 0.047 0.049 0.065 0.059 0.064 0.046 0.054 0.065
0.925 0.047 0.048 0.050 0.074 0.068 0.072 0.047 0.060 0.074
0.930 0.047 0.048 0.051 0.075 0.070 0.073 0.047 0.061 0.076
0.950 0.048 0.048 0.054 0.088 0.082 0.083 0.048 0.068 0.091
0.960 0.048 0.049 0.057 0.093 0.087 0.088 0.048 0.072 0.097
0.975 0.050 0.051 0.067 0.108 0.100 0.100 0.050 0.082 0.110
0.980 0.051 0.052 0.075 0.113 0.104 0.104 0.051 0.087 0.114
0.990 0.058 0.058 0.104 0.136 0.118 0.118 0.058 0.102 0.136
Table 16. Cumulative Distributions of Zenith Atmospheric Attenuation at Ka-Band
for Goldstone DSCC, dB
CD January February March April May June
0.000 0.116 0.116 0.116 0.116 0.116 0.116
0.100 0.135 0.133 0.136 0.139 0.145 0.142
0.200 0.140 0.139 0.141 0.146 0.154 0.150
0.250 0.141 0.141 0.143 0.148 0.156 0.153
0.300 0.144 0.144 0.145 0.151 0.161 0.157
0.400 0.149 0.148 0.150 0.154 0.169 0.163
0.500 0.154 0.152 0.154 0.158 0.180 0.173
0.600 0.162 0.157 0.159 0.163 0.188 0.188
0.700 0.175 0.165 0.165 0.169 0.198 0.204
0.800 0.195 0.181 0.175 0.176 0.212 0.218
0.850 0.216 0.195 0.182 0.180 0.224 0.227
0.900 0.253 0.223 0.194 0.188 0.246 0.245
0.925 0.300 0.246 0.201 0.193 0.264 0.264
0.930 0.308 0.252 0.203 0.194 0.268 0.266
0.950 0.377 0.288 0.216 0.202 0.315 0.289
0.960 0.426 0.319 0.233 0.208 0.337 0.310
0.975 0.568 0.388 0.281 0.229 0.402 0.373
0.980 0.625 0.419 0.311 0.250 0.422 0.405
0.990 0.863 0.542 0.444 0.344 0.512 0.542
Table 16 (Cont'd). Cumulative Distributions of Zenith Atmospheric Attenuation at
Ka-Band
for Goldstone DSCC, dB
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 0.116 0.116 0.116 0.116 0.116 0.116 0.116 0.116 0.116
0.100 0.154 0.157 0.164 0.148 0.138 0.133 0.133 0.144 0.164
0.200 0.171 0.173 0.173 0.155 0.145 0.139 0.139 0.152 0.173
0.250 0.175 0.179 0.177 0.157 0.147 0.141 0.141 0.155 0.179
0.300 0.183 0.190 0.184 0.162 0.151 0.144 0.144 0.160 0.190
0.400 0.194 0.204 0.196 0.170 0.158 0.148 0.148 0.167 0.204
0.500 0.210 0.222 0.212 0.176 0.166 0.152 0.152 0.176 0.222
0.600 0.229 0.234 0.224 0.183 0.179 0.157 0.157 0.185 0.234
0.700 0.253 0.242 0.241 0.192 0.192 0.167 0.165 0.197 0.253
0.800 0.273 0.256 0.257 0.206 0.207 0.184 0.175 0.211 0.273
0.850 0.283 0.265 0.267 0.216 0.217 0.202 0.180 0.223 0.283
0.900 0.298 0.281 0.291 0.234 0.234 0.233 0.188 0.243 0.298
0.925 0.309 0.292 0.306 0.244 0.245 0.256 0.193 0.260 0.309
0.930 0.313 0.295 0.308 0.246 0.246 0.263 0.194 0.263 0.313
0.950 0.328 0.315 0.326 0.260 0.256 0.321 0.202 0.291 0.377
0.960 0.340 0.328 0.344 0.273 0.267 0.360 0.208 0.312 0.426
0.975 0.381 0.369 0.396 0.314 0.300 0.464 0.229 0.371 0.568
0.980 0.407 0.375 0.450 0.338 0.333 0.511 0.250 0.403 0.625
0.990 0.534 0.400 0.706 0.452 0.471 0.704 0.344 0.541 0.863
Table 17. Cumulative Distributions of Zenith Atmospheric Attenuation at Ka-Band
for Canberra DSCC, dB
CD January February March April May June
0.000 0.126 0.126 0.126 0.126 0.126 0.126
0.100 0.201 0.230 0.248 0.195 0.176 0.171
0.200 0.223 0.253 0.267 0.212 0.184 0.190
0.250 0.232 0.264 0.273 0.217 0.187 0.194
0.300 0.238 0.277 0.279 0.223 0.191 0.196
0.400 0.251 0.302 0.293 0.233 0.198 0.202
0.500 0.274 0.326 0.307 0.246 0.205 0.208
0.600 0.297 0.354 0.329 0.258 0.212 0.216
0.700 0.323 0.389 0.355 0.274 0.226 0.225
0.800 0.356 0.436 0.384 0.302 0.271 0.240
0.850 0.378 0.486 0.405 0.324 0.303 0.256
0.900 0.422 0.624 0.447 0.368 0.369 0.290
0.925 0.465 0.737 0.495 0.442 0.455 0.346
0.930 0.475 0.761 0.511 0.459 0.482 0.371
0.950 0.555 0.913 0.593 0.547 0.622 0.502
0.960 0.612 1.013 0.639 0.613 0.727 0.561
0.975 0.786 1.337 0.770 0.796 0.983 0.698
0.980 0.897 1.533 0.874 0.891 1.055 0.769
0.990 1.535 2.181 1.198 1.168 1.378 0.948
Table 17 (Cont'd). Cumulative Distributions of Zenith Atmospheric Attenuation at
Ka-Band for Canberra DSCC, dB
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 0.126 0.126 0.126 0.126 0.126 0.126 0.126 0.126 0.126
0.100 0.164 0.166 0.180 0.181 0.206 0.184 0.164 0.192 0.248
0.200 0.174 0.176 0.191 0.196 0.223 0.204 0.174 0.208 0.267
0.250 0.178 0.180 0.196 0.201 0.230 0.214 0.178 0.214 0.273
0.300 0.181 0.182 0.200 0.205 0.237 0.222 0.181 0.219 0.279
0.400 0.187 0.187 0.210 0.214 0.252 0.238 0.187 0.230 0.302
0.500 0.195 0.193 0.219 0.225 0.266 0.253 0.193 0.243 0.326
0.600 0.203 0.201 0.229 0.242 0.283 0.272 0.201 0.258 0.354
0.700 0.213 0.212 0.246 0.265 0.308 0.299 0.212 0.278 0.389
0.800 0.234 0.230 0.269 0.314 0.366 0.350 0.230 0.312 0.436
0.850 0.253 0.252 0.291 0.351 0.422 0.399 0.252 0.343 0.486
0.900 0.285 0.305 0.331 0.428 0.511 0.480 0.285 0.404 0.624
0.925 0.327 0.359 0.370 0.516 0.601 0.554 0.327 0.471 0.737
0.930 0.338 0.374 0.386 0.540 0.624 0.581 0.338 0.490 0.761
0.950 0.391 0.454 0.482 0.702 0.764 0.698 0.391 0.600 0.913
0.960 0.431 0.529 0.556 0.798 0.853 0.759 0.431 0.671 1.013
0.975 0.518 0.784 0.717 1.084 1.188 0.922 0.518 0.876 1.337
0.980 0.566 0.871 0.823 1.278 1.353 0.997 0.566 0.985 1.533
0.990 0.744 1.194 1.315 1.783 1.854 1.269 0.744 1.364 2.181
Table 18. Cumulative Distributions of Zenith Atmospheric Attenuation at Ka-Band
for Madrid DSCC, dB
CD January February March April May June
0.000 0.121 0.121 0.121 0.121 0.121 0.121
0.100 0.138 0.138 0.155 0.157 0.181 0.191
0.200 0.150 0.148 0.165 0.169 0.195 0.205
0.250 0.153 0.151 0.168 0.172 0.199 0.209
0.300 0.157 0.155 0.173 0.176 0.205 0.215
0.400 0.165 0.161 0.181 0.183 0.215 0.224
0.500 0.177 0.171 0.191 0.193 0.222 0.233
0.600 0.192 0.183 0.202 0.206 0.231 0.242
0.700 0.222 0.196 0.219 0.223 0.242 0.251
0.800 0.297 0.221 0.252 0.260 0.269 0.264
0.850 0.382 0.257 0.289 0.297 0.326 0.274
0.900 0.541 0.332 0.370 0.355 0.454 0.292
0.925 0.725 0.412 0.462 0.414 0.593 0.308
0.930 0.757 0.429 0.481 0.428 0.621 0.313
0.950 1.021 0.560 0.599 0.549 0.792 0.358
0.960 1.122 0.634 0.675 0.621 0.887 0.399
0.975 1.371 0.848 0.886 0.788 1.117 0.541
0.980 1.448 0.922 0.969 0.839 1.204 0.641
0.990 1.754 1.218 1.264 1.031 1.508 1.052
Table 18 (Cont'd). Cumulative Distributions of Zenith Atmospheric Attenuation at
Ka-Band
for Madrid DSCC, dB
CD July August September October November Dec. Minimum Year Maximum
Average
0.000 0.121 0.121 0.121 0.121 0.121 0.121 0.121 0.121 0.121
0.100 0.201 0.202 0.190 0.171 0.119 0.138 0.119 0.165 0.202
0.200 0.213 0.215 0.206 0.194 0.152 0.152 0.148 0.180 0.215
0.250 0.217 0.219 0.211 0.201 0.157 0.157 0.151 0.184 0.219
0.300 0.222 0.226 0.218 0.211 0.166 0.166 0.155 0.191 0.226
0.400 0.231 0.234 0.230 0.227 0.176 0.180 0.161 0.200 0.234
0.500 0.238 0.242 0.241 0.244 0.188 0.194 0.171 0.211 0.244
0.600 0.246 0.251 0.254 0.263 0.205 0.213 0.183 0.224 0.263
0.700 0.254 0.260 0.266 0.290 0.228 0.246 0.196 0.241 0.290
0.800 0.263 0.272 0.282 0.353 0.272 0.322 0.221 0.277 0.353
0.850 0.269 0.279 0.293 0.427 0.340 0.406 0.257 0.319 0.427
0.900 0.279 0.290 0.314 0.568 0.478 0.549 0.279 0.401 0.568
0.925 0.286 0.297 0.338 0.714 0.627 0.687 0.286 0.486 0.725
0.930 0.287 0.299 0.343 0.742 0.651 0.707 0.287 0.501 0.757
0.950 0.298 0.310 0.391 0.958 0.857 0.879 0.298 0.624 1.021
0.960 0.305 0.320 0.440 1.061 0.947 0.962 0.305 0.689 1.122
0.975 0.330 0.350 0.606 1.325 1.190 1.187 0.330 0.864 1.371
0.980 0.351 0.372 0.736 1.438 1.257 1.259 0.351 0.938 1.448
0.990 0.460 0.468 1.253 1.896 1.532 1.520 0.460 1.225 1.896
Table 19. Monthly and Year-Average Rainfall Amounts at the DSN Antenna Locations
Month Goldstone Canberra Madrid
inches mm inches mm inches mm
January 1.02 25.9 3.61 91.7 1.48 37.5
February 1.18 30.0 2.74 69.7 1.38 35.0
March 0.90 22.9 2.90 73.6 1.10 28.0
April 0.20 5.1 2.85 72.4 1.87 47.5
May 0.19 4.8 2.94 74.8 1.56 39.5
June 0.04 1.0 2.70 68.7 1.26 32.0
July 0.35 8.9 3.36 85.3 0.57 14.5
August 0.59 15.0 3.90 99.0 0.59 15.0
September 0.39 9.9 3.73 94.7 1.16 29.5
October 0.15 3.8 3.70 94.0 1.54 39.0
November 0.23 5.8 3.50 88.8 2.01 51.0
December 0.57 14.5 2.42 61.4 1.75 44.5
Year 5.81 147.6 38.67 982.1 16.26 413.0
Average
Table 20. Parameters for X-Band Planetary Noise Calculation, plus X-Band and Ka-
Band Noise Temperatures at Mean Minimum Distance from Earth
Planet Diameter Mean Mean Black- T_Planet at Mean Minimum
(km) Distance Distance body Distance (K)
from from Sun Disk
Earth Temp
(K)
X-Band Ka-Band
(10^6 km) 70-m 34-m 34-m (78.8
(74.4 (68.3 dBi gain)
dBi dBi
gain) gain)
polar equa- min Max. 10^6km AU
torial
Mercury 4880 91.7 207.5 57.9 0.387 625 3.05 0.75 8.39
Venus 12104 41.4 257.8 108.3 0.723 490 72.10 17.70 198.58
Earth 12757 - - 149.6 1.000 250-300^1 - - -
Mars 6794 78.3 377.5 227.9 1.523 180 2.33 0.57 6.43
Jupiter 134102 142984 628.7 927.9 778.3 5.203 152 13.53 3.32 37.27
Saturn 108728 120536 1279.8 1579.0 1429.4 9.555 155 2.37 0.58 6.52
Uranus 51118 2721.4 3020.6 2871.0 19.191 160 0.10 0.02 0.27
Neptune 49532 4354.4 4653.6 4504.0 30.107 160 0.04 0.01 0.10
Pluto 2274 5763.9 6063.1 5913.5 39.529 160 0.00 0.00 0.00
Note:
1. Ocean (250) and Land (300)
810-005, Rev. E
DSMS Telecommunications Link
Design Handbook
201
Frequency and Channel Assignments
Effective November 30, 2000
Document Owner: Approved by:
----------------------- -----------------------
C.J. Ruggier Date A. Kwok Date
Tracking System Engineer Tracking and Navigation Services
System Development Engineer
Prepared by: Released by:
[Signature on file in TMOD Library]
------------------------ ---------------------------
R.W. Sniffin Date TMOD Document Release Date
Change Log
Rev Issue Date Affected Paragraphs Change Summary
Initial 1/15/2001 All All
Note to Readers
There are two sets of document histories in the 810-005 document, and these
histories are reflected in the header at the top of the page. First, the entire document is
periodically released as a revision when major changes affect a majority of the modules. For
example, this module is part of 810-005, Revision E. Second, the individual modules also
change, starting as an initial issue that has no revision letter. When a module is changed, a
change letter is appended to the module number on the second line of the header and a summary
of the changes is entered in the module's change log.
This is a new module in Revision E of 810-005.
Contents
Paragraph Page
1 Introduction.......................................................................................... 4
1.1 Purpose and Scope................................................................................... 4
2 General Information................................................................................... 4
2.1 Tracking Modes of Operation......................................................................... 5
2.1.1 One-way........................................................................................... 5
2.1.2 Two-way........................................................................................... 5
2.1.3 Three-way......................................................................................... 5
2.1.4 Coherent Three-way............................................................................... 5
2.2 Spacecraft Transponder Turnaround Ratios............................................................ 5
2.3 Frequency Bands Allocated by the International Telecommunication Union (ITU)........................ 6
2.4 Deep Space Coherent Frequency Channels.............................................................. 7
Tables
Table Page
1. Spacecraft Transponder Turnaround Ratios............................................................. 6
2. Allocated Frequency Bands............................................................................ 6
3. Frequency and Channel Assignments for S-Band Uplink.................................................. 9
4. Frequency and Channel Assignments for X-Band Uplink................................................. 10
5. Frequency and Channel Assignments for Ka-Band Uplink............................................... 11
1 Introduction
1.1 Purpose and Scope
This module provides basic information about the frequencies that are
available in the Deep Space Network (DSN) and presents the way certain of the
DSN frequency allocations have been divided into channels. It does not specify
which stations can or will support assigned frequencies. That information is
contained in the appropriate Telecommunications Interfaces modules (101, 70-m
Antenna Subnet Telecommunications Interfaces; 102, 26-m Antenna Subnet
Telecommunications Interfaces; 103, 34-m HEF Antenna Subnet Telecommunications
Interfaces; or 104, 34-m BWG Stations Telecommunications Interfaces) of this
handbook. It also does not include propagation characteristics of the
frequencies. This information is provided in module 105 (Atmospheric and
Environmental Effects) and module 106 (Solar Corona and Solar Wind Effects) of
this handbook.
2 General Information
The DSN has developed channel plans to provide for orderly selection
and assignment of frequencies for deep-space missions (Category B, greater than
2 million km from Earth). (The DSN has not developed channel plans for near-
Earth missions [Category A, less than 2 million km from Earth].) The deep space
channel plans are based on bandwidth, hardware implementation, and transponder
turnaround-ratio considerations. The plans must allow phase coherent uplink
(Earth-to-space) and downlink (space-to-Earth) transmissions.
Through international agreements, the International Telecommunications
Union (ITU) allocates and regulates portions of the frequency spectrum for both
commercial and government use. The primary objective of the ITU is to establish
regulatory procedures for the coordinated use of frequencies by those agencies
permitted to operate in the allocated bands. The ITU has allocated certain bands
to deep space (Category B) research. In some cases, the deep space missions may
be required to conditionally share a frequency band between multiple users in
the same band.
The Consultative Committee for Space Data Systems (CCSDS) is an
international organization for space agencies interested in mutually developing
standard transmission and data handling techniques to support space research,
including space science and applications. As a member of the CCSDS, NASA has
submitted recommendations for various space systems applications. As an example,
the standard NASA Ka-band spacecraft transponder turnaround
ratio was first presented for review and approval to the CCSDS prior to its
implementation.
The National Telecommunications and Information Administration
(NTIA), an agency of the U.S. Department of Commerce, is the Executive
Branch's principal authority on domestic and international telecommunications
and information technology issues. During the planning phase of all missions
using the DSN, the proposed operating frequencies and other operating
parameters are reviewed by the NTIA for approval through the System Review
process. The NTIA evaluations are based upon the technical and regulatory
criteria for the efficient and coordinated use of the frequency spectrum by
NASA missions.
2.1 Tracking Modes of Operation
The following paragraphs describe the various ways in which the
telecommunications link can be configured for radio tracking. The source of
the uplink signal and the choice of references for measuring the received
frequency determine the mode of operation.
2.1.1 One-way
The spacecraft generates the downlink signal(s) from an onboard
oscillator. The DSN compares the received frequency against a locally
generated frequency.
2.1.2 Two-way
The DSN transmits a signal to the spacecraft. The spacecraft tracks
the phase of the uplink signal and generates a phase coherent downlink signal.
The DSN compares the received frequency with the same reference frequency from
which the uplink was generated.
2.1.3 Three-way
The spacecraft is tracked by two stations-one with the two-way mode
while the other receives and compares the signal to a locally generated
frequency. The most common application of this mode is during the handover
between stations at two different Deep Space Communication Complexes (DSCCs).
2.1.4 Coherent Three-way
Coherent three-way tracking is three-way tracking when the
transmitting and receiving stations share a common reference frequency.
2.2 Spacecraft Transponder Turnaround Ratios
To measure two-way or three-way Doppler shift, the spacecraft must
transmit a downlink signal that is phase coherent with the uplink signal. Table
1 provides the recommended spacecraft transponder turnaround ratios for various
uplink and downlink frequency bands. The tracking equipment at the DSN 34-m and
70-m stations can accommodate other turnaround ratios but this support must be
negotiated through the JPL Frequency Manager, who is resident in the Plans and
Commitments Program Office .
Table 1. Spacecraft Transponder Turnaround Ratios
Uplink Downlink Ratio (downlink/uplink)
S S 240/221
S X 880/221
S Ka 3344/221
X S 240/749
X X 880/749
X Ka 3344/749
Ka S 240/3599*
Ka X 880/3599*
Ka Ka 3344/3599*
* While these are the recommended ratios, all existing Ka-band
spacecraft have used turnaround ratios negotiated through the JPL
Frequency Manager.
Frequency Bands Allocated by the International
Telecommunication Union (ITU)
Frequency ranges have been allocated by the ITU for use in deep space
and near-Earth research. These ranges are listed in Table 2.
Table 2. Allocated Frequency Bands
Band Deep Space Bands (for spacecraft > 2 million km Near Earth Bands (for spacecraft < 2 million km from
Designation from Earth) Earth)
Uplink (Earth to Downlink (space to Earth) Uplink (Earth to Downlink (space to Earth)
space) space)
S-band 2110-2120 2290-2300 2025-2110 2200-2290
X-band 7145-7190 8400-8450 7190-7235 8450-8500
Ka-band 34200-34700 31800-32300
Deep Space Coherent Frequency Channels
The DSN has divided the frequency ranges allocated for deep space use
into channels for tracking support associated with a given transponder ratio.
The frequency ranges allocated for near-Earth uses do not have a formal
channelization plan. Tables 3, 4, and 5 list the 42-channel assignments by
frequency bands. Note that frequencies out of the allocated ranges for deep
space research are not shown in the tables.
The S-band downlink center frequency (F_ch(14) = 2295 MHz) is used to
derive all entries in the tables using the expressions
F_ch(n-1) = F_ch(n) - (10/27), rounded to the nearest hertz for n = 2 to
14
F_ch(n+1) = F_ch(n) + (10/27), rounded to the nearest hertz for n = 14
to 41
where F_ch(n) is the center frequency (in MHz) of channel n rounded
to the nearest Hz, and the ratio 10/27 is the spacing (in MHz) between the
centers of two adjacent channels.
Frequencies for other columns are derived by the procedure described
below. The calculated downlink frequencies may differ by 1 or 2 hertz between
the tables because each table assumes an integer uplink frequency and precise
turnaround ratios.
(1) The uplink frequency specified in the table is calculated from the
expression
F_ch(n)= F_ch(n) x TM/240, rounded to the nearest hertz,
where
F_ch(n) is the frequency of uplink channel n being calculated;
F_ch(n) is the frequency of channel n calculated for the S-band
downlink column
(including values for out-of-band channels); TM is the
transmit multiplier of a frequency band, that
is, TM = 221, 749, and 3599 for S uplink, X
uplink, and Ka uplink.
(2) The downlink frequencies specified in the table are calculated from
the expression F_ch(n) = F_ch(n) x TR, rounded to the nearest hertz,
where F_ch(n) is the frequency of channel n for the downlink columns;
F_ch(n) is the frequency of channel n in the uplink column;
TR is the turnaround ratio for the downlink frequency band as
provided in Table 1.
The DSN only supports two-way or three-way tracking with uplink and
downlink frequencies having the same channel number. Therefore, only channels 5
through 27 fully support coherent uplink and downlink for all frequency bands.
Channel 28, for example, supports S- or X-band uplink with coherent X- or Ka-
band downlink, but not with coherent S-band
downlink.
Before selecting operating frequencies or channels for a project,
the telecommunication designer should consult the JPL Frequency Manager, who
is resident in the Plans and Commitments Program Office
, to avoid frequency interference with
other spacecraft, present or planned.
Table 3. Frequency and Channel Assignments for S-band Uplink Table 4. Frequency
and Channel Assignments for X-band Uplink Table 5. Frequency and Channel
Assignments for Ka-band Uplink
Channel S-band U/L (MHz) S-band D/L (MHz) X-band D/L (MHz) Ka-band D/L (MHz)
5 2110.243056 2291.666667 8402.777780 31930.555562
6 2110.584105 2292.037037 8404.135803 31935.716050
7 2110.925154 2292.407407 8405.493826 31940.876538
8 2111.266204 2292.777778 8406.851853 31946.037042
9 2111.607253 2293.148148 8408.209876 31951.197530
10 2111.948303 2293.518519 8409.567903 31956.358033
11 2112.289352 2293.888889 8410.925927 31961.518521
12 2112.630401 2294.259259 8412.283950 31966.679009
13 2112.971451 2294.629630 8413.641977 31971.839512
14 2113.312500 2295.000000 8415.000000 31977.000000
15 2113.653549 2295.370370 8416.358023 31982.160488
16 2113.994599 2295.740741 8417.716050 31987.320991
17 2114.335648 2296.111111 8419.074073 31992.481479
18 2114.676697 2296.481481 8420.432097 31997.641967
19 2115.017747 2296.851852 8421.790124 32002.802470
20 2115.358796 2297.222222 8423.148147 32007.962958
21 2115.699846 2297.592593 8424.506174 32013.123462
22 2116.040895 2297.962963 8425.864197 32018.283950
23 2116.381944 2298.333333 8427.222220 32023.444438
24 2116.722994 2298.703704 8428.580248 32028.604941
25 2117.064043 2299.074074 8429.938271 32033.765429
26 2117.405092 2299.444444 8431.296294 32038.925917
27 2117.746142 2299.814815 8432.654321 32044.086420
28 2118.087191 8434.012344 32049.246908
29 2118.428241 8435.370371 32054.407411
30 2118.769290 8436.728395 32059.567899
31 2119.110339 8438.086418 32064.728387
32 2119.451389 8439.444445 32069.888891
33 2119.792438 8440.802468 32075.049379
Channel X-band U/L (MHz) S-band D/L (MHz) X-band D/L (MHz) Ka-band D/L (MHz)
1 7147.286265 2290.185185 31909.913580
2 7148.442131 2290.555556 31915.074083
3 7149.597994 2290.925926 8400.061729 31920.234571
4 7150.753857 2291.296296 8401.419752 31925.395059
5 7151.909723 2291.666667 8402.777779 31930.555562
6 7153.065586 2292.037037 8404.135802 31935.716050
7 7154.221449 2292.407407 8405.493825 31940.876538
8 7155.377316 2292.777778 8406.851853 31946.037042
9 7156.533179 2293.148148 8408.209877 31951.197530
10 7157.689045 2293.518519 8409.567903 31956.358033
11 7158.844908 2293.888889 8410.925927 31961.518521
12 7160.000771 2294.259259 8412.283950 31966.679009
13 7161.156637 2294.629630 8413.641977 31971.839512
14 7162.312500 2295.000000 8415.000000 31977.000000
15 7163.468363 2295.370370 8416.358023 31982.160488
16 7164.624229 2295.740741 8417.716050 31987.320991
17 7165.780092 2296.111111 8419.074073 31992.481479
18 7166.935955 2296.481481 8420.432097 31997.641967
19 7168.091821 2296.851852 8421.790123 32002.802470
20 7169.247684 2297.222222 8423.148147 32007.962958
21 7170.403551 2297.592593 8424.506175 32013.123462
22 7171.559414 2297.962963 8425.864198 32018.283950
23 7172.715277 2298.333333 8427.222221 32023.444438
24 7173.871143 2298.703704 8428.580248 32028.604941
25 7175.027006 2299.074074 8429.938271 32033.765429
26 7176.182869 2299.444444 8431.296295 32038.925917
27 7177.338735 2299.814815 8432.654321 32044.086420
28 7178.494598 8434.012345 32049.246908
29 7179.650464 8435.370372 32054.407411
30 7180.806327 8436.728395 32059.567899
31 7181.962190 8438.086418 32064.728387
32 7183.118057 8439.444446 32069.888891
33 7184.273920 8440.802469 32075.049379
34 7185.429783 8442.160493 32080.209867
35 7186.585649 8443.518520 32085.370370
36 7187.741512 8444.876543 32090.530858
37 7188.897378 8446.234570 32095.691361
Channel Ka-band U/L (MHz) S-band D/L (MHz) X-band D/L (MHz) Ka-band D/L (MHz)
1 34343.235337 2290.185185 31909.913578
2 34348.789359 2290.555556 31915.074080
3 34354.343365 2290.925926 8400.061729 31920.234569
4 34359.897372 2291.296296 8401.419752 31925.395058
5 34365.451394 2291.666667 8402.777779 31930.555560
6 34371.005401 2292.037037 8404.135802 31935.716049
7 34376.559407 2292.407407 8405.493826 31940.876538
8 34382.113429 2292.777778 8406.851853 31946.037040
9 34387.667436 2293.148148 8408.209876 31951.197529
10 34393.221458 2293.518519 8409.567903 31956.358031
11 34398.775465 2293.888889 8410.925926 31961.518520
12 34404.329471 2294.259259 8412.283950 31966.679009
13 34409.883493 2294.629630 8413.641977 31971.839511
14 34415.437500 2295.000000 8415.000000 31977.000000
15 34420.991507 2295.370370 8416.358023 31982.160489
16 34426.545529 2295.740741 8417.716050 31987.320991
17 34432.099535 2296.111111 8419.074074 31992.481480
18 34437.653542 2296.481481 8420.432097 31997.641969
19 34443.207564 2296.851852 8421.790124 32002.802471
20 34448.761571 2297.222222 8423.148147 32007.962960
21 34454.315593 2297.592593 8424.506174 32013.123462
22 34459.869599 2297.962963 8425.864198 32018.283951
23 34465.423606 2298.333333 8427.222221 32023.444440
24 34470.977628 2298.703704 8428.580248 32028.604942
25 34476.531635 2299.074074 8429.938271 32033.765431
26 34482.085641 2299.444444 8431.296295 32038.925920
27 34487.639663 2299.814815 8432.654322 32044.086422
28 34493.193670 8434.012345 32049.246911
29 34498.747692 8435.370372 32054.407414
30 34504.301699 8436.728395 32059.567902
31 34509.855705 8438.086419 32064.728391
32 34515.409727 8439.444446 32069.888894
33 34520.963734 8440.802469 32075.049382
34 34526.517741 8442.160492 32080.209871
35 34532.071763 8443.518519 32085.370373
36 34537.625769 8444.876543 32090.530862
37 34543.179791 8446.234570 32095.691365
38 34548.733798 8447.592593 32100.851853
39 34554.287805 8448.950616 32106.012342
40 34559.841827 32111.172845
41 34565.395833 32116.333333
42 34570.949840 32121.493822
810-005, Rev. E
DSMS Telecommunications Link
Design Handbook
202, Rev. A
34-m and 70-m Doppler
December 15, 2002
Document Owner: Approved by:
----------------------- --------------------------
C.J. Ruggier Date J.B. Berner Date
Tracking System Engineer Tracking and Navigation Services
Development Engineer
Prepared by: Released by:
[Signature on file in TMOD Library]
------------------------ ---------------------------
P.W. Kinman Date TMOD Document Release Date
Change Log
Rev Issue Date Affected Paragraphs Change Summary
Initial 1/15/2001 All All
Note to Readers
There are two sets of document histories in the 810-005 document, and these
histories are reflected in the header at the top of the page. First, the entire document is
periodically released as a revision when major changes affect a majority of the modules. For
example, this module is part of 810-005, Revision E. Second, the individual modules also
change, starting as an initial issue that has no revision letter. When a module is changed, a
change letter is appended to the module number on the second line of the header and a summary
of the changes is entered in the module's change log.
Contents
Paragraph Page
1. Introduction......................................................................................... 4
1.1 Purpose............................................................................................. 4
1.2 Scope............................................................................................... 4
2. General Information ................................................................................. 4
2.1 Doppler Measurement Error .......................................................................... 7
2.1.1 Measurement Error for One-Way Doppler............................................................. 9
2.1.2 Measurement Error for Two-Way and Three-Way Doppler .............................................. 9
2.2 Carrier Tracking .................................................................................. 10
2.2.1 Carrier Loop Bandwidth .......................................................................... 10
2.2.2 Static Phase Error in the Carrier Loop........................................................... 10
2.2.3 Carrier Phase Error Variance .................................................................... 11
2.2.4 Carrier Power Measurement ....................................................................... 12
2.3 Doppler Measurement With Small Sun-Earth-Probe Angles ............................................. 12
2.3.1 Doppler Measurement Error ....................................................................... 13
2.3.2 Carrier Phase Error Variance .................................................................... 14
Appendix A References.................................................................................. 20
Illustrations
Figure Page
1. One-Way Doppler Measurement ......................................................................... 6
2. Two/Three-Way Doppler Measurement.................................................................... 6
3. Doppler Measurement Error Due to Solar Phase Scintillation: S-Up/S-Down............................. 15
4. Doppler Measurement Error Due to Solar Phase Scintillation: S-Up/X-Down ............................ 16
5. Doppler Measurement Error Due to Solar Phase Scintillation: X-Up/X-Down............................. 17
6. Doppler Measurement Error Due to Solar Phase Scintillation: X-Up/S-Down ............................ 18
7. Doppler Measurement Error Due to Solar Phase Scintillation: X-Up/Ka-Down............................ 19
Table
Table Page
1. Static Phase Error ................................................................................. 12
1. Introduction
1.1 Purpose
This module provides sufficient information for the telecommunications engineer
to understand the capabilities and limitations of the equipment used for Doppler measurement at
the Deep Space Network (DSN) 34-m and 70-m stations.
1.2 Scope
The scope of this module is limited to those features of the Downlink Channel at
the 34-m High-efficiency (34-m HEF), 34-m Beam Waveguide (34-m BWG), and 70-m stations
that relate to the measurement of and reporting of the Doppler effect. This module does not
discuss the capabilities of the equipment used for Doppler measurement at the DSN 34-m Highspeed
Beam Waveguide (HSB) station.
2. General Information
The relative motion of a transmitter and receiver causes the received frequency to
differ from that of the transmitter. This is the Doppler effect. In deep space communications it is
usual to define Doppler as the transmitted frequency (the uplink) minus the received frequency
(the downlink) divided by the ratio that was used onboard the spacecraft (the transponding ratio)
to generate the downlink frequency. For the receding spacecraft that are typical of deep space
exploration, the Doppler so defined is a positive quantity. Since the frequency of a carrier equals
the rate-of-change of carrier phase, the Downlink Channel supports Doppler measurement by
extracting the phase of the downlink carrier (Reference 1).
There are three types of Doppler measurement: one-way, two-way, and threeway.
In all of these cases, the accumulating downlink carrier phase is measured and recorded.
When the measurement is one-way, the frequency of the spacecraft transmitter must typically be
inferred. A much more accurate Doppler measurement is possible when the spacecraft coherently
transponds a carrier arriving on the uplink. In such a case, the downlink carrier frequency is
related to the uplink carrier frequency by a multiplicative constant, the transponding ratio. Also,
the downlink carrier phase equals the uplink carrier phase multiplied by this transponding ratio.
Thus, when an uplink signal is transmitted by the DSN and the spacecraft coherently transponds
this uplinked signal, a comparison of the uplink transmitter phase record with the downlink
receiver phase record gives all the information necessary for an accurate computation of the
combined Doppler on uplink and downlink. When one Deep Space Station (DSS) both provides
the uplink and receives the downlink, so that there are two "nodes" (the DSS and the spacecraft)
present, then it is a two-way measurement. When one DSS provides the uplink and another
receives the downlink, so that there are three nodes present, then it is a three-way measurement.
Figure 1 illustrates one-way Doppler measurement. The measurement is
referenced to the signal originating on the spacecraft. The frequency stability of the spacecraft
oscillator used to generate the downlink carrier will, in general, limit the performance of this
Doppler measurement. Usually, only Ultra-Stable Oscillators (USOs) are used for one-way
Doppler measurement.
Figure 2, Two/Three-Way Doppler Measurement, illustrates the more usual
means of measuring Doppler. The measurement originates at a DSS. The uplink carrier
frequency is synthesized within the exciter from a highly stable frequency reference provided by
the Frequency and Timing Subsystem (FTS). Since this reference is much more stable than
anything that a spacecraft-borne oscillator could provide, a two-way or three-way Doppler
measurement is more accurate than a one-way measurement. The uplink carrier may be either
constant or varied in accord with a tuning plan. In either case, the phase of the uplink carrier is
recorded for use in the computation of a Doppler effect.
For all Doppler measurements (one-, two-, and three-way), the downlink signal is
routed from the Antenna Feed/Low Noise Amplifier (LNA) to the Downlink Channel. This is
reflected in Figures 1 and 2. Within the Radio-frequency to Intermediate-frequency
Downconverter (RID), which is located at the antenna, a local oscillator is generated by
frequency multiplication of a highly stable frequency reference from the FTS and the incoming
downlink signal is heterodyned with this local oscillator. The Intermediate-Frequency (IF) signal
that results is sent to the Signal Processing Center (SPC).
In the SPC, the IF to Digital Converter (IDC) alters the frequency of the IF signal
by a combination of up-conversion and down-conversion to a final analog frequency of
approximately 200 MHz and then performs analog-to-digital conversion. The final analog stage
of down-conversion uses a local oscillator supplied by the Channel-Select Synthesizer (CSS),
which is also part of the Downlink Channel. The CSS is adjusted before the beginning of a pass
to a frequency appropriate for the anticipated frequency range of the incoming downlink signal.
During the pass, the frequency of the CSS remains constant. The local oscillator frequencies of
the CSS (and, indeed, of all local oscillators in the analog chain of down-conversion) are
synthesized within the Downlink Channel from highly stable frequency references provided by
the FTS. All analog stages of down-conversion are open-loop, and so the digital signal coming
out of the IDC reflects the full Doppler effect on the downlink carrier.
The Receiver and Ranging Processor (RRP) accepts the signal from the IDC and
extracts carrier phase with a digital phase-locked loop (Reference 2). The loop is configured to
track the phase of a phase-shift keyed signal with residual carrier, a suppressed carrier, or a
QPSK signal. Since every analog local oscillator is held at constant frequency during a pass, the
downlink carrier phase at sky frequency (that is, the phase that arrives at the DSS antenna) is
easily computed from the local oscillator frequencies and the time-varying phase extracted by the
digital phase-locked loop.
Since Doppler is a difference of frequencies and a frequency is a derivative of
phase, a record of phase transmitted on the uplink and of phase received on the downlink is
sufficient to compute the combined uplink/downlink Doppler. It is important to note that these
Figure 1. One-Way Doppler Measurement
(Figure omitted in text-only document)
Figure 2. Two/Three-Way Doppler Measurement
(Figure omitted in text-only document)
phase records must account for integer as well as fractional cycles. (This is unlike many
telecommunications applications where it is necessary to know the carrier phase only modulo
one cycle.) The data are uplink and downlink phase counts at sky frequency (only downlink
phase counts in the case of a one-way measurement). The downlink phase counts are available at
0.1-second intervals. The uplink phase counts are available from the Uplink Processor Assembly
(UPA) at 1.0-second intervals.
2.1 Doppler Measurement Error
Only errors in measuring the rate-of-change of the distance between phase centers
of the antennas are considered here. There are other errors that must be considered in any
navigation solution, such as those introduced by propagation through the troposphere, the
ionosphere, and the solar corona. Additional information on the effect of the solar corona on
Doppler measurement is contained in paragraph 2.3.
Each error is characterized here as a standard deviation of range-rate sigma_V and is in
units of velocity. To translate any of these errors to a standard deviation of frequency sf, the
following equation can be used.
sigma_f = 2f_c/c * sigma_v (1)
where
f_c = the downlink carrier frequency and
c = the speed of light in vacuum.
Equation (1) is for two-way and three-way Doppler measurement. (The factor of 2 is absent for
one-way Doppler measurement.)
When tracking a residual carrier, the carrier loop signal-to-noise ratio is
rho_L = P_c/N_0 |_D/L * 1/B_L (2)
where P_C/N_0 |_D/L is the downlink carrier power to noise spectral density ratio, Hz.
There is an additional loss to the carrier loop signal-to-noise ratio when tracking a
residual carrier with non-return-to-zero symbols in the absence of a subcarrier. This loss is due to
the presence of data sidebands overlaying the residual carrier in the frequency domain and
therefore increasing the effective noise level for carrier synchronization. In this case, rho_L must be
calculated as (Reference 3)
rho_L = P_C/N_0 |_D/L * (1/B_L) * 1/(1 + 2E_S/N_0) (4)
where
P_T/N_0|_D/L = downlink total signal power to noise spectral density ratio, Hz
S_L = squaring loss of the Costas loop (Reference 4),
S_L = (2E_S/N_0)/(1 + 2E_S/N_0) (5)
When tracking QPSK, the carrier loop signal-to-noise ratio is
rho_L = P_T/N_0|_D/L * S_LQ/B_L (6)
where S_LQ is the squaring loss of the QPSK Costas loop (Reference 5),
S_LQ = 1/(1 + 9/(2E_SQ/N_0) + 6/(E_SQ/N_0)^2 + 3/(2(E_SQ/N_0)^3)) (7)
where E_SQ/N0 is the energy per quaternary channel symbol to noise spectral
density ratio.
When telemetry data in a non-return to zero (NRZ) format directly modulate the
carrier (that is, no subcarrier) and there is an imbalance in the data (that is, an unequal number of
logical ones and zeros), a residual-carrier loop will experience an additional jitter. This jitter
represents an additional error source for Doppler measurement. The size of this error
contribution is strongly dependent on the statistics of the telemetry data.
2.1.1 Measurement Error for One-Way Doppler
Measurement error for one-way Doppler is normally dominated by the relative
instability of the spacecraft oscillator and by the lack of knowledge of the exact frequency of this
oscillator. Associated with one-way Doppler measurement is an unknown bias due to uncertainty
in the transmitted frequency. In addition, there is a random error due to instability of the
spacecraft oscillator. This latter error may be roughly modeled as
sigma_V = sqrt(2)c * sigma_y
where
sigma_v = the standard deviation of range-rate in velocity units,
c = the speed of light in vacuum, and
sigma_y = the Allan deviation of the spacecraft oscillator.
The Allan deviation is a function of integration time.
2.1.2 Measurement Error for Two-Way and Three-Way Doppler
Measurement errors for two-way coherent and three-way coherent Doppler must
include the effect of jitter introduced by the spacecraft receiver. The two-way or three-way
coherent Doppler measurement error due to thermal noise is approximated by
sigma_v = c/(2sqrt(2)(pi)f_c * T) * sqrt(1/rho_L + G^2B_L/(P_C/N_0|_U/L))
where
T = measurement integration time, s
f_C = downlink carrier frequency, Hz
c = speed of light in vacuum, mm/s
G = transponding ratio
B_L = one-sided, noise-equivalent, loop bandwidth of downlink carrier loop, Hz
P_C/N_0|_U/L = uplink carrier power to noise spectral density ratio, Hz
rho_L = downlink carrier loop signal-to-noise ratio.
Equation (9) assumes that the transponder (uplink) carrier loop bandwidth is large compared
with the DSS (downlink) carrier loop bandwidth, which is typically the case.
2.2 Carrier Tracking
The Downlink Channel can be configured to track phase-shift keyed telemetry
with residual carrier or a suppressed carrier or a QPSK signal. In order to achieve good Doppler
measurement performance, it is important to characterize the phase error in the carrier loop.
2.2.1 Carrier Loop Bandwidth
The one-sided, noise-equivalent, carrier loop bandwidth is denoted B_L.The user
may choose to change B_L during a tracking pass, and this can be implemented without losing
phase-lock, assuming the change is not too large.
There are limits on the carrier loop bandwidth. B_L can be no larger than 200 Hz.
The lower limit on B_L is determined by the phase noise on the downlink. In addition, when
operating in the suppressed-carrier mode, B_L is subject to the following constraint.
B_L = R_SYM/20, suppressed carrier, (10)
where R_SYM is the telemetry symbol rate.
In general, the value selected for B_L should be small in order to maximize the
carrier loop signal-to-noise ratio. On the other hand, B_L must be large enough that neither of the
following variables becomes too large: the static phase error due to Doppler dynamics and the
contribution to carrier loop phase error variance due to phase noise on the downlink. The best B_L
to select will depend on circumstances. Often, it will be possible to select a B_L of less than 1 Hz.
A larger value for B_L is necessary when there is significant uncertainty in the downlink Doppler
dynamics, when the downlink is one-way (or two-way non-coherent) and originates with a less
stable oscillator (such as an Auxiliary Oscillator), or when the Sun-Earth-probe angle is small (so
that solar phase scintillations are present on the downlink).
When tracking a spinning spacecraft, it may be necessary to set the carrier loop
bandwidth to a value that is somewhat larger than would otherwise be needed. The loop
bandwidth must be large enough to track out the variation due to the spin. Also, the coherent
AGC in the receiver must track out the amplitude variations.
The user may select either a type 2 or type 3 carrier loop. Both loop types are
perfect, meaning that the loop filter implements a true accumulation.
2.2.2 Static Phase Error in the Carrier Loop
The carrier loop, with either a type 2 or type 3 loop, has a very large tracking
range; even a Doppler offset of several megahertz can be tracked. With a finite Doppler rate,
however, there will be a static phase error in a type 2 loop.
Table 1, Static Phase Error (rad), shows the static phase error in the carrier loop
that results from various Doppler dynamics for several different loops. These equations are based
on the work reported in Reference 6. The Doppler dynamics are here defined by the parameters
alpha and beta.
alpha = Doppler Rate (Hz/s)
beta = Doppler Acceleration (Hz/s^2)
In the presence of a persistent Doppler acceleration, a type 2 loop will periodically slip cycles.
The equations of Table 1 are valid when tracking phase-shift keyed telemetry with
either residual or suppressed carrier or a QPSK signal. These equations are exactly the same as
those appearing in Appendix C of module 207, 34-m and 70-m Telemetry.
2.2.3 Carrier Phase Error Variance
When the spacecraft is tracked one-way, the carrier phase error variance sigma_phi^2 is given by
sigma_phi^2 = 1/rho_L + sigma_S^2 (11)
When the spacecraft is tracked in a two-way or three-way coherent mode, the
carrier phase error variance sigma_phi^2 is given by
sigma_phi^2 = 1/rho_L + G^2(B_TR-B_L)/(P_C/N_0|_U/L) + sigma_S^2 (12)
where
B_TR = one-sided, noise-equivalent, transponder carrier loop bandwidth, Hz
sigma_phi^2 = contribution to carrier loop phase error variance due to solar phase
scintillations, rad^2 (see paragraph 2.3.2)
and the other parameters are as defined in paragraph 2.1.2.
It is recommended that the following constraint on carrier phase error variance be observed.
sigma_phi^2 <= { 0.10 rad^2, residual carrier (13)
{ 0.02 rad^2, suppressed carrier
Table 1. Static Phase Error (rad)
Loop Range-Rate Derivate of Range-Rate Second Deriviate of Range-Rate
(Constant Doppler Offset) (Constant Doppler Rate) (Constant Doppler Acceleration)
type 2, 0 9(pi)/(16B_L^2) * alpha (9(pi)beta/(16B_L^2))t - 27(pi)beta/(64B_L^3)
standard
underdamped
type 2, 0 25(pi)/(32B_L^2) (25(pi)beta/(32B_L^2))t - 125(pi)beta/(128B_L^3)
supercritically
damped
type 3, 0 0 12167(pi)/(8000B_L^3) * beta
standard
underdamped
type 3, 0 0 35937(pi)/(16384B_L^3) * beta
supercritically
damped
2.2.4 Carrier Power Measurement
When the downlink is residual-carrier, an estimate of the downlink carrier power
P_C is available. When the downlink is suppressed-carrier, an estimate of the total downlink
power P_T is available. This is done by first estimating P_C/N_0|_D/L (with a modified version of the
algorithm described in Reference 7) or P_T/N_0|_D/L (with the split-symbol moments algorithm
described in Reference 8). An estimate of the noise spectral density N0 comes from continual
measurements made by a noise-adding radiometer. This information is used to compute absolute
power P_C or P_T. The results are reported once per second.
2.3 Doppler Measurement With Small Sun-Earth-Probe Angles
When the Sun-Earth-probe angle is small and the spacecraft is beyond the Sun,
microwave carriers pick up phase scintillations in passing through the solar corona. There is a
resulting contribution to Doppler measurement error and also an increase in the carrier loop
phase error variance. The magnitudes of these effects are highly variable, depending on the
activity of the Sun.
2.3.1 Doppler Measurement Error
Equations (14) and (15), below, based on the work reported in Reference 9, offer
a coarse estimate of the average solar contribution to the standard deviation of Doppler
measurement error. Equation (14) is valid when tracking phase-shift keyed telemetry with either
residual or suppressed carrier or a QPSK signal, but only for Sun-Earth-Probe angles between 5 degrees
and 27 degrees. In general, the standard deviation of Doppler measurement error will be the root-sumsquare
of the error standard deviation due to thermal noise, which is given in Equation (9), and
the error standard deviation due to solar phase scintillations, which is given in Equation (14).
sigma_V = (0.73c * sqrt(C_band) * [sin(theta_SEP)]^-1.225)/(f_C * T^0.175) (14)
where
T = the measurement integration time in seconds,
fC = the downlink carrier frequency in hertz,
c = the speed of light in vacuum (~= 3 x 10^11 mm/s), and
?_SEP = the Sun-Earth-probe angle.
The result, sigma_V, will have the same units as c.
The constant C_band depends on the uplink/downlink bands; it is given by
Cband = { 6.1 x 10-5, S-up/S-down (15)
{ 4.8 x 10-4, S-up/X-down
{ 2.6 x 10-5, X-up/S-down
{ 5.5 x 10-6, X-up/X-down
{ 5.2 x 10-5, X-up/Ka-down
{ 1.9 x 10-6, Ka-up/X-down
{ 2.3 x 10-7, Ka-up/Ka-down
Figure 3 shows sigma_V as a function of Sun-Earth-probe angle for two-way or threeway
Doppler measurement with an S-band uplink and an S-band downlink. The vertical axis is in
units of mm/s. The three curves in that figure correspond to measurement integration times of 5,
60, and 1000 seconds. Figure 4 shows sigma_V for an S-band uplink and an X-band downlink. Figure
5 shows sigma_V for an X-band uplink and an X-band downlink. Figure 6 shows sigma_V for an X-band
uplink and an S-band downlink. Figure 7 shows sigma_V for an X-band uplink and a Ka-band
downlink.
2.3.2 Carrier Phase Error Variance
Equation (16), below, based on the work reported in Reference 9, offers a coarse
estimate of the average solar contribution, in units of rad^2, to carrier loop phase error variance.
Equation (16) is valid when tracking phase-shift keyed telemetry with either residual or
suppressed carrier or a QPSK signal, but only for Sun-Earth-Probe angles between 5 degrees and 27 degrees.
sigma_S^2 = (C_band * C_loop)/(sin(theta_SEP)^2.45 * B_L^1.65), 5 degrees <= theta_SEP <= 27 degrees (16)
In Equation (16), ?_SEP is the Sun-Earth-probe angle and B_L is the carrier loop bandwidth. C_band is
given by Equation (15) for two-way and three-way coherent operation and by
C_band = { 2.6 x 10^-5, S-down (17)
{ 1.9 x 10-6, X-down
{ 1.3 x 10-7, K_a - down
for non-coherent operation.
C_loop is a constant depending on the type of carrier loop selected.
C_loop = { 5.9, standard underdamped type 2 loop (18)
{ 5.0, supercritically damped type 2 loop
{ 8.2, standard underdamped type 3 loop
{ 6.7, supercritically damped type 3 loop
Equation (16) together with Equations (15), (17), and (18) give the contribution of
solar coronal phase scintillation to carrier loop phase error variance. It is used in Equation (12) to
compute the total carrier loop phase error variance.
Figure 3. Doppler Measurement Error Due to Solar Phase Scintillation: S-Up/S-Down
(Figure omitted in text-only document)
Figure 4. Doppler Measurement Error Due to Solar Phase Scintillation: S-Up/X-Down
(Figure omitted in text-only document)
Figure 5. Doppler Measurement Error Due to Solar Phase Scintillation: X-Up/X-Down
(Figure omitted in text-only document)
Figure 6. Doppler Measurement Error Due to Solar Phase Scintillation: X-Up/S-Down
(Figure omitted in text-only document)
Figure 7. Doppler Measurement Error Due to Solar Phase Scintillation: X-Up/Ka-Down
(Figure omitted in text-only document)
Appendix A
References
1. P. W. Kinman, "Doppler Tracking of Planetary Spacecraft," IEEE Transactions
on Microwave Theory and Techniques, Vol. 40, No. 6, pp. 1199-1204, June 1992.
2. J. B. Berner and K. M. Ware, "An Extremely Sensitive Digital Receiver for Deep
Space Satellite Communications," Eleventh Annual International Phoenix
Conference on Computers and Communications, pp. 577-584, Scottsdale,
Arizona, April 1-3, 1992.
3. J. Lesh, "Tracking Loop and Modulation Format Considerations for High Rate
Telemetry," DSN Progress Report 42-44, Jet Propulsion Laboratory, Pasadena,
CA, pp. 117-124, April 15, 1978.
4. M. K. Simon and W. C. Lindsey, "Optimum Performance of Suppressed Carrier
Receivers with Costas Loop Tracking," IEEE Transactions on Communications,
Vol. COM-25, No. 2, pp. 215-227, February 1977.
5. J. H. Yuen, editor, Deep Space Telecommunications Systems Engineering,
Plenum Press, New York, pp. 94-97, 1983.
6. S. A. Stephens and J. B. Thomas, "Controlled-Root Formulation for Digital
Phase-Locked Loops," IEEE Transactions on Aerospace and Electronic Systems,
Vol. 31, No. 1, pp. 78-95, January 1995.
7. A. Monk, "Carrier-to-Noise Power Estimation for the Block-V Receiver," TDA
Progress Report 42-106, Jet Propulsion Laboratory, Pasadena, CA, pp. 353-363,
August 15, 1991.
8. S. Dolinar, "Exact Closed-Form Expressions for the Performance of the Split-
Symbol Moments Estimator of Signal-to-Noise Ratio," TDA Progress Report 42-
100, pp. 174-179, Jet Propulsion Laboratory, Pasadena, CA, February 15, 1990.
9. R. Woo and J. W. Armstrong, "Spacecraft Radio Scattering Observations of the
Power Spectrum of Electron Density Fluctuations in the Solar Wind," Journal of
810-005, Rev. E
DSMS Telecommunications Link
Design Handbook
203
Sequential Ranging
Effective November 30, 2000
Document Owner: Approved by:
----------------------- -----------------------
C.J. Ruggier Date A. Kwok Date
Tracking System Engineer Tracking and Navigation Services
System Development Engineer
Prepared by: Released by:
[Signature on file in TMOD Library]
------------------------ ------------------------
R.W. Sniffin Date TMOD Document Release Date
Change Log
Rev Issue Date Affected Paragraphs Change Summary
Initial 1/15/2001 All All
Note to Readers
There are two sets of document histories in the 810-005 document, and these
histories are reflected in the header at the top of the page. First, the entire document is
periodically released as a revision when major changes affect a majority of the modules. For
example, this module is part of 810-005, Revision E. Second, the individual modules also
change, starting as an initial issue that has no revision letter. When a module is changed, a
change letter is appended to the module number on the second line of the header and a summary
of the changes is entered in the module's change log.
Module 203 supersedes module TRK-30, Rev. E, dated January 15, 1998, in 810-005.
Contents
Contents
Paragraph Page
1 Introduction.......................................................................................... 6
1.1 Purpose ............................................................................................ 6
1.2 Scope .............................................................................................. 6
2 General Information................................................................................... 6
2.1 Network Simplification Project Ranging.............................................................. 7
2.2 System Description.................................................................................. 7
2.3 Parameters Specified for Ranging Operations ........................................................ 9
2.3.1 Transmit Time and Receive Time ................................................................... 9
2.3.2 Clocks and Components ............................................................................ 9
2.3.3 Square-Wave and Sine-Wave Ranging ............................................................... 11
2.3.4 Integration Times ............................................................................... 12
2.3.4.1 T_1............................................................................................ 12
2.3.4.2 T_2............................................................................................ 14
2.3.4.3 T_3............................................................................................ 17
2.3.4.3 Cycle Time .................................................................................... 17
2.3.5 Modulation Index ................................................................................ 18
2.3.6 Frequency Chopping............................................................................... 19
2.3.7 Other Parameters ................................................................................ 20
2.3.7.1 Tolerance ..................................................................................... 20
2.3.7.2 Servo ......................................................................................... 20
2.3.7.3 Pipe........................................................................................... 21
2.4 Range Measurement Process ......................................................................... 22
2.4.1 Range Measurement Technique ..................................................................... 22
2.4.2 P_r/N_0.......................................................................................... 24
2.4.2 Figure of Merit ................................................................................. 25
2.4.3 Differenced Range Versus Integrated Doppler ..................................................... 28
2.5 Ratio of Downlink Ranging Power to Total Power .................................................... 28
2.6 Range Corrections ................................................................................. 30
2.6.1 DSS Delay........................................................................................ 31
2.6.2 Z-Correction..................................................................................... 32
2.6.3 Antenna Correction .............................................................................. 32
2.7 Error Contributions................................................................................ 35
Appendix A, The Current DSN Ranging System............................................................. 36
A1.0 System Description Using the Sequential Ranging Assembly ......................................... 36
A2.0 Range Measurement Process Using the SRA .......................................................... 37
A3.0 Performance Differences .......................................................................... 38
A3.1 Integration Times ................................................................................ 38
A3.1.1 T_1............................................................................................. 38
A3.1.2 T_2............................................................................................. 40
A3.1.3 T_3............................................................................................. 40
A3.2 Other SRA Ranging Parameters...................................................................... 40
A3.3 SRA Calculations ................................................................................. 40
A3.3.1 Cycle Time ..................................................................................... 40
A3.3.2 P_r/N_o ........................................................................................ 40
A4.0 Range Corrections Using the SRA................................................................... 44
A4.1 DSS Delay......................................................................................... 44
A4.2 Antenna Calibration............................................................................... 44
A5.0 Error Contributions for Ranging Using the SRA..................................................... 45
Illustrations
Figure Page
1. The NSP Era DSN Ranging System Architecture ......................................................... 8
2. Integration Time T_1 Versus P_r/N_o, Clock Frequency Fc = 1 MHz, for Sine-Wave Ranging.............. 14
3. Integration Time T_1 Versus P_r/N_o, Clock Frequency Fc = 500 kHz, for Square-Wave Ranging.......... 15
4. Code Component Integration Time T_1 Versus P_r/N_o for Various Probabilities of Error and n = 5..... 16
5. Code Component Integration Time T_1 Versus P_r/N_o for Various Probabilities of Error and n = 10.... 16
6. Code Component Integration Time T_1 Versus P_r/N_o for Various Probabilities of Error and n = 20.... 17
7. Chopping of C5, C6, and C7 (by C4).................................................................. 21
8. Component Acquisition Process ...................................................................... 23
9. Figure of Merit, with T_2 = 5 sec for Various Frequency Components. ................................ 26
10. Figure of Merit, with T_2 = 50 sec for Various Frequency Components ............................... 27
11. Figure of Merit, with T_2 = 500 s for Various Frequency Components................................. 27
12. Pr/Pt as a Function of (gamma)RNG/DN for Selected Values of Modulation Index theta DN ............. 30
13. DSN Range Measurement.............................................................................. 31
14. Typical DSS Delay Calibration...................................................................... 33
15. Measuring the Z-Component ......................................................................... 34
A-1. Current DSN Ranging System ....................................................................... 37
A-2. Integration Time T_1 Versus P_r/N_o, Clock Frequency F_c = 1 MHz,
for Sine-Wave Ranging Using the SRA .............................................................. 41
A-3. Integration Time T_1 Versus P_r/N_o, Clock Frequency F_c = 500 kHz, for
Square-Wave Ranging Using the SRA ................................................................ 42
A-4. Code Component Integration Time T_1 Versus P_r/N_o for Various Probabilities of Error and n = 5 .. 42
A-5. Code Component Integration Time T_1 Versus P_r/N_o for Various Probabilities of Error and n = 10 . 43
A-6. Code Component Integration Time T_1 Versus P_r/N_o for Various Probabilities of Error and n = 20 . 43
A-7. Typical Range Calibration Signal Path for DSS Using SRA and MDA Ranging Equipment ................ 45
Tables
Table Page
1. Range Code Resolving Capability .................................................................... 11
2. One-Sigma Range Error for NSP Era Ranging System.................................................... 35
A-1. One Sigma Range Error for SRA/MDA-Equipped Ranging System ........................................ 46
1 Introduction
1.1 Purpose
This module describes the Ranging capabilities of the Network
Simplification Project (NSP) and provides the performance parameters of the Deep
Space Network (DSN) Sequential Ranging equipment for the 70-m, the 34-m High
Efficiency (HEF), and the 34-m Beam Waveguide (BWG) subnets. Appendix A gives a
description of the ranging architecture and performance for the 26-m subnet and
the 34-m High-speed Beam Waveguide (HSB) antenna that are not included in the
NSP implementation scheme, and for the 70-m, 34-m HEF, and 34-m BWG subnets
prior to the NSP implementation.
1.2 Scope
The material contained in this module covers the sequential ranging
system that is utilized by both near-Earth and deep space missions. This
document describes those parameters and operational considerations that are
independent of the particular antenna being used to provide the
telecommunications link. For antenna-dependent parameters, refer to the
appropriate telecommunications interface module, modules 101, 102, 103, and 104
of this handbook. Other ranging schemes employed by the DSN include the tone
ranging system, described in module 204 and the pseudo random noise (PN) and
regenerative ranging, described in module 214.
2 General Information
The DSN ranging system provides a sequentially binary-coded ranging
scheme to measure the round-trip light time (RTLT) between a Deep Space Station
(DSS) and a spacecraft. An uplink signal is transmitted to a spacecraft where
it is received by the on-board transponder, then demodulated, filtered, and
remodulated onto the downlink carrier. The downlink signal received at the DSS
is correlated with a Doppler-modified replica of the transmitted codes that were
sent to the spacecraft approximately one RTLT earlier. Using Doppler rate-
aiding, the RTLT is determined by measuring the phase difference between the
received code and the transmitted code.
The three basic tracking modes are one-way, two-way, and three-way. In
the one-way tracking mode, the spacecraft generates a downlink signal that is
received by the Earth-based station without a transmission being made to the
spacecraft. Two-way tracking consists of transmitting an uplink to a spacecraft
where it is received and coherently transmitted as a downlink to the same Earth
station. For the three-way tracking mode, two-way tracking is performed by an
Earth station, while another station tracks the downlink signal using a
different antenna and possibly a different frequency standard.
The parameters to be specified for ranging operations are explained in Paragraph
2.3. Paragraph 2.4 presents the process of range measurement that includes the
evaluation of RTLT, ranging-power-to-noise ratio (P_r/N_o), figure of merit (FOM), and
differenced range versus integrated Doppler (DRVID). The relationship of
downlink ranging power over total power is given in Paragraph 2.5. Paragraph
2.6 provides the corrections required to determine the actual range to a
spacecraft. Error contributions of the ground system are discussed in
Paragraph 2.7.
2.1 Network Simplification Project Ranging
The Deep Space Network is undergoing a redesign of the uplink and
downlink architecture to achieve simplified operations and increased
performance. A major feature of the modification is the splitting of the
ranging and Doppler uplink and downlink functions, allowing recovery from
anomalies on one without affecting the other.
In contrast to the previous design that employed a separate piece of
equipment called the sequential ranging assembly (SRA), the new ranging system
does not require a real-time interface between the uplink and downlink
elements. There is a connection between the uplink and downlink in the sense
that both elements must send data to a common node. However, the digital time-
tagged data can be passed to the common node in non-real time, without loss of
range measurement accuracy. The lack of a hardware connection to between the
uplink and downlink elements of single antenna to the ranging equipment makes
it possible to perform range measurements in the three-way tracking mode.
NSP ranging replaces the SRA with separate uplink and downlink
ranging processors. Local code models are generated that match the SRA
sequential tone ranging. The Tracking Data Delivery Subsystem (TDDS) replaces
the Metric Data Assembly (MDA) and the Radio Metric Data Conditioning (RMDC)
function of preparing the data for delivery to the user.
Ranging code components cover 1 MHz to 1 Hz in steps of powers of 2
provided by software local code models. Correlation of the ranging signal to
determine clock phase and range ambiguity is handled using software algorithms.
2.2 System Description
The NSP architecture for the DSN ranging system is shown in Figure 1.
It consists of a front end portion, an uplink portion, and a downlink portion.
The front-end portion consists of the microwave components, including a Low-
noise Amplifier (LNA) and the antenna. The uplink portion includes the Uplink
Ranging Assembly (URA), an exciter, the transmitter, and the controller,
referred to as the Uplink Processor Assembly (UPA). The downlink portion
includes the RF-to-IF Downconverter (RID), the IF-to-Digital Converter (IDC),
the Receiver and Ranging Processor (RRP) and the Downlink Channel Controller
(DCC). The Downlink Telemetry and Tracking Subsystem (DTT) and the Uplink
Subsystem (UPL) provide the essential functional capability for NSP ranging.
Figure 1. The NSP Era DSN Ranging System Architecture
(Figure omitted in text-only document)
Control of the ranging function is within the DTT. Control signals
from the DTT are coupled to the URA in the UPL via the Reliable Network Service
(RNS) and the UPA. The URA generates the sequential ranging codes for two-way
and three-way ranging and forwards them to the exciter where they are modulated
onto the uplink. It also monitors the uplink ranging phase and forwards this
data to the TDDS.
The amplified downlink signal from the microwave is downconverted by
the RID (located on the antenna) and fed to the IDC where it is sampled at 160
Msamples/s into an 8-bit digital signal at the RRP. After processing, the
downlink range phase data are delivered to the TDDS by the Downlink Channel
Controller (DCC), via the station RNS and a similar function at JPL. The TDDS
formats the ranging data and passes the uplink and downlink phase information to
the Navigation subsystem (NAV). Subsequently, the NAV provides the ranging data
to projects.
Each DTT Controller Processing Cabinet (DCPC) is equipped with a
single channel, which includes a single RRP. For spacecraft with multiple
channels (for example, S-band and X-band), or for multiple spacecraft within
a single antenna beamwidth, multiple DCPCs will be assigned to that antenna.
In addition to producing downlink phase information, the RRP
generates a 66-MHz ranging reference analog signal with a Numerically
Controlled Oscillator (NCO). The ranging reference frequency F_RNG (ref), is
computed from the received frequency, f_r, as follows:
F_RNG (ref ) = F_r/(32K) (1)
where:
F_r = received carrier frequency
K = normalization factor (independent of uplink frequency)
240/221 (S-down)
880/221 (X-down)
3344/221 (Ka-down).
2.3 Parameters Specified for Ranging Operations
The following paragraphs present the parameters that are required
in ranging operations.
2.3.1 Transmit Time and Receive Time
The rabging system needs a transmit time (XMIT) and an a-priori
estimate of the RTLT, truncated to the nearest second, in order that the code
sequence sent by the UPL can be correlated for measuring the phase shift through
the round-trip-time delay. When a XMIT and an approximate RTLT are specified,
the DTT automatically calculates the receive time To by adding the two
quantities, T_o = XMIT + RTLT. This T_o is also called the start time of the
correlation process for the code sequence. The two time quantities must be
specified to the nearest second.
2.3.2 Clocks and Components
A range measurement begins with the highest frequency code followed
by subsequent codes each having a frequency exactly half of the previous one.
The first code in the sequence is called the clock component and determines the
resolution of the measurement. The lower frequency codes that follow are used
to resolve the ambiguity (uncertainty) of the a-priori range estimate.
1 shows the clocks and components used in ranging operations. A
total of 21 code components are available. They are referred to as component
numbers 4 through 24 as shown in the Table. The first 7 components (numbered 4
through 10) are called the clock components or simply clocks. The approximate
ambiguity resolving capability of a component is listed for reference. The
approximate frequencies and periods of the codes are also shown.
The exact clock frequency (Fc) to replace the approximate
frequency in the second column is computed by the relationship:
F_C = F_66/2^(2+n) (2)
where n is an integer from 4 to 24 that represents a code component or a
component number and F_66 is the exciter reference frequency.
The value of F_66 used to produce Table 1 was exactly 66.000 MHz. In
ranging operations, this frequency varies depending upon the transmitting
(uplink) carrier frequency. F_66 is denoted by F_66S or F_66X depending on whether
it was derived from an S-band or X-band uplink frequency and can be expressed in
terms of the uplink frequency as follows:
S-band uplink:
F_66S = F_ts/32 (3)
X-band Uplink
F_66X = 221/749 * F_tx/32 (4)
where, F_ts and F_tx are the S- and X-band transmitting (uplink) frequencies.
The third column (approximate period) shows the periods of the
corresponding frequencies in the second column. The fourth column (ambiguity
resolving capability) lists the products of the periods and the speed of
light (299,792.5 km/s), divided by a factor of 2 to determine the one-way
distance.
Depending on the uncertainty of the range estimate, a flight project
determines the number of components needed for ranging operations. An example in
choosing the clock and components is given as follows:
Example: Suppose the spacecraft is known to be at a 10-minute RTLT
from Earth to within +/-100,000 km. If it is desired to resolve the ambiguity to
about 40,000 km, and if the distance is desired to be resolved to within 150 m,
then components 4 through 22 should be defined for ranging. That is, clock 4
(about 1 MHz) is used with the subsequent 18 components (5 through 22).
Table 1. Range Code Resolving Capability
Component Approximate Approximate Approximate
Number Frequency Period (s) Ambiguity Resolving
(Hz) Capability (km)
4* 1,030,000.000 9.700E-07 0.1450
5* 516,000.000 1.940E-06 0.2910
6* 258,000.000 3.880E-06 0.5810
7* 129,000.000 7.760E-06 1.160
8* 64,500.000 1.550E-05 2.330
9* 32,200.000 3.100E-05 4.650
10* 16,100.000 6.210E-05 9.30
11 8,060.000 1.240E-04 18.60
12 4,030.000 2.480E-04 37.20
13 2,010.000 4.960E-04 74.40
14 1,010.000 9.930E-04 149.0
15 504.000 1.990E-03 298.0
16 252.000 3.970E-03 595.0
17 126.000 7.940E-03 1,190.0
18 62.900 1.590E-02 2,380.0
19 31.500 3.180E-02 4,760.0
20 15.700 6.360E-02 9,530.0
21 7.870 1.270E-01 19,100.0
22 3.930 2.540E-01 38,100.0
23 1.970 5.080E-01 76,200.0
24 0.983 1.020E+00 152,000.0
* available clocks
2.3.3 Square-Wave and Sine-Wave Ranging
The DTT may process the received codes in two ranging modes. They are
referred to as square-wave and sine-wave operation. For square-wave operation,
the DTT processes all harmonics of the received codes. For sine-wave operation,
only the fundamental (the first harmonic) is processed. Square-wave operation is
the default because, with the exception of the higher frequency clock
components, the codes are received as square waves. However, sinewave operation
may be desirable if non-linearities or other processes exist that may delay the
range code fundamental and its harmonics differently. The two modes can be
summarized by:
Square-wave operation: transmit square waves
correlate as square waves
Sine-wave operation: transmit square waves
correlate as sine waves
Ranging with the 500-kHz and 1-MHz clocks are special cases due to the
limited ranging bandwidths of most spacecraft and an intentional 1.2 MHz
bandwidth limit in the DSN ranging modulators. This limit has been installed to
prevent interference with services adjacent to the DSN uplink allocations . The
ranging equipment presently requires the 1 MHz clock to be processed using sine-
wave correlation. If square-wave correlation is specified, the 500 kHz code will
be processed using the square-wave correlation algorithm although only its
fundamental will have been transmitted to the spacecraft.
2.3.4 Integration Times
Three integration times must be specified for ranging operations.
They are: T_1 for clock integration, T_2 for each lower-frequency component
integration, and T_3 for DRVID measurement(s).
2.3.4.1 T_1
T_1 is the total time used to integrate the correlation samples for
the clock component. It is a function of the clock frequency, the desired
variance of RTLT measurements, and the ranging signal to noise spectral density
and can be calculated by the following expressions:
Sine-wave operation:
T_1 = 1/64 x 1/F_c^2 x 1/(sigma^2(t)) x 1/(P_r/N_o), s (5)
where
F_c = the clock frequency, Hz
sigma^2(t) = the desired variance of the RTLT measurements, s^2
P_r/N_o = the ranging signal to noise spectral density, Hz
The factor 1/64 has been derived empirically from the most probable
variance of a range point when using sine-wave correlation.
Square-wave operation:
T_1 = 1/49 x 1/F_c^2 x 1/(sigma^2(t)) x 1/(P_r/N_o), s (6)
where
F_c , sigma^2(t), and P_r/N_o are as above and the factor 1/49 has been
derived empirically from the upper bound variance of the 1 MHz sine-wave
ranging when using square-wave correlation.
The above equations can be rewritten in terms of the uncertainty sigma(r)
in meters, by multiplying the uncertainty sigma(t) in seconds by the speed of light
and dividing by a factor of 2. This provides:
Sine-wave operation:
sigma(r) = sqrt(352/(F_c^2(MHz) x T_1 x P_r/N_o)), m (7)
Square-wave operation:
sigma(r) = sqrt(458/(F_c^2(MHz) x T_1 x P_r/N_o)), m (8)
where:
F_c = the clock frequency, MHz
T_1 = the clock component integration time, s
P_r/N_o = the ranging signal to noise spectral density, Hz.
Note: The uncertainty, sigma, here is only due to thermal noise. Other
errors must be added to this to get the total uncertainty (see Paragraph 2.7).
Figure 2 plots integration time (T_1) as a function of P_r/N_o for sine-
wave operation using a 1 MHz clock component with sigma(r) as a parameter. For a
desired sigma(r), the user may find the proper integration time, T_1, for an
estimated P_r/N_o (in dB-Hz). Figure 3 is a similar graph for square-wave
operation using a 500-kHz clock component. This figure may also be used for
lower frequency square-wave clocks by recognizing that dividing F_c by 2 will
result in T_1, being multiplied by 2^2, etc.
Figure 2. Integration Time T_1 Versus P_r/N_o, Clock Frequency F_c = 1 MHz, for Sine-Wave Ranging
(Figure omitted in text only document)
Ranging is possible as long as the receiver remains in lock over the measurement
time. However, there is a practical lower limit for P_r/N_o (usually about -10 dB-
Hz) determined by the combination of integration times (cycle time) and the
minimum number of range points needed by the project. See Cycle Time in
Paragraph 2.3.4.4 for further details.
2.3.4.2 T_2
T_2 is the integration time for each of the lower-frequency
components. It is a function of P_r/N_o and the probability of error in acquiring
all components (excluding the clock). In general, T_2 is given by the following
equation
T_2 = 1/(P_r/N_0) x {InvErf[2(1-P_e)^(1/(n-1)) - 1]}^2, s (9)
Figure 3. Integration Time T_1 Versus P_r/N_o, Clock Frequency F_c = 500 kHz, for Square-Wave Ranging
(Figure omitted in text-only document)
where
Pr_N0 = the ranging signal to noise spectral density, Hz
InvErf[*] = the inverse error fo the * quantity
P_e = the probability of error in acquiring all (n-1) components.
n = the total number of components including the clock being acquired.
Figures 4 through 6 show T_2 versus P_r/N_o for various P_e and n. An appropriate T_2
for ranging operations can be determined from these curves by choosing the desired n,
the desired, P_e, and the estimated P_r/N_o.
Figure 4. Code Component Integration Time T_1 Versus P_r/N_o for Various
Probabilities of Error and n = 5
(Figure omitted in text-only document)
Figure 5. Code Component Integration Time T_1 Versus P_r/N_o for Various
Probabilities of Error and n = 10
(Figure omitted in text-only document)
Figure 6. Code Component Integration Time T_1 Versus P_r/N_o for
Various Probabilities of Error and n = 20
(Figure omitted in text-only document)
2.3.4.3 T_3
T_3 is the integration time for differenced range versus integrated Doppler
(DRVID) measurements (see Paragraph 2.4.3 for a further discussion of
DRVID). Since the phase information is already available from the clock
acquisition, T_3 can be less than T_1 (typically 7/8 T_1).
2.3.4.3 Cycle Time
Cycle time is the total time that the DTT spends to perform
measurements for the clock, the (n-1) components, and the DRVIDs. It also
includes some dead time between component integrations to accomodate the 1-
second inaccuracy permitted in specifying the estimated RTLT. In other words, it
is the time required to complete one range acquisition. The cycle time (CYC) is
automatically calculated by the DTT, and it is given by the following formula:
CYC= (2+T_1) + (1+T_2)(n-1) + DRVN(2+T_3) + 1, s (10)
where
T_1 = clock integration time
T_2 = component integration times
T_3 = DRVID integration time
n = the total number of components including the clock
DRVN= the number of DRVIDs specified for the acquisition.
For a typical 8-hour tracking pass, it is recommended that CYC be
less than the following limits:
Soft limit: CYC <= 30 minutes
Hard limit: CYC <= 55 minutes.
The chance of getting a desired number of good range points decreases
substantially as the cycle time approaches the 55-minute limit. Any glitch
occurring in the system during the time of measurement will cause a range point
to become invalid. It is better to stay closer to, or within the soft limit.
2.3.5 Modulation Index
In ranging operations, square-wave codes are modulated on the uplink
carrier by the exciter phase modulator. This results in an attenuation of
carrier power and a corresponding increase of power spread into the sidebands.
The phase displacement of the carrier due to modulation is referred to as the
modulation index and may be specified as a peak-to-peak or root mean square
(RMS) value. That is, if the modulation waveform is specified as peak-to-peak
value, the modulation index will define the peak-to-peak phase modulation. If,
on the other hand, the modulation waveform is specified as an RMS value, the
modulation index will define the RMS phase modulation The expressions for
carrier power and ranging power are given in terms of the modulation index as
follows:
P_c = P_t (cos^2(theta)), numeric, units of power (11)
P_r = P_t (sin^2(theta)), numeric, units of power (12)
where:
P_c= the carrier power
P_r= the ranging power
P_t= the total power before ranging modulation (that is, P_t = P_c + P_r)
theta = the modulation index in radians (or degrees).
Therefore, the carrier suppression in dB is given by:
P_c/P_t = 10log(cos^2(theta)) . (13)
The modulators used in the DSN operate over the range of 0.1 to 1.5
radians, peak. It should be noted that equation 13 assumes ideal conditions,
and variations between the calculated and that measured values of carrier
suppression may occur depending on the amplitude, frequency, and phase
responses of the modulator in use.
Example: An unmodulated signal is received by a spacecraft with Pt = -100 dBm.
When this signal is modulated by square waves of a 30-deg modulation index,
the carrier power (P_c) becomes -101.25 dBm (suppressed by 1.25 dB) and the
ranging (sidebands) power (P_r) is -106.0 dBm (P_r = -100 dBm + 10log(sin(30)^2)).
2.3.6 Frequency Chopping
Separation between the ranging modulation products and the carrier
frequency decreases as a ranging acquisition steps through the code components
of the lower frequencies. If this were allowed to continue, 1) the receiver
tracking loop would follow the waveform and track out the code(s); or 2)
interference occurs to the telemetry or command modulation. A frequency chopping
modulation function can be enabled to prevent these problems. The function is
defined by:
C=C_m # C_c
where:
C = modulation
C_m = the square-wave modulation of the component, m, being chopped
C_c = the square-wave modulation of the clock component
# = modulo 2 addition
The chopping process results in a power spectrum for a sideband pair relative to
the ranging power as follows:
P_k/P_r = 10log{8 x [tan(k(pi)/(2^(m-n+1)))/(k(pi))]^2}, dB (15)
where
P_k = the power of the k-th odd sideband pair (a perfect square wave will not have any even harmonics)
P_r = the total ranging power (all sidebands)
m = the component number being chopped
n = the number of the clock (2 to 10)
k = the odd sideband-pair number of the component being chopped.
The physical meaning of chopping can best be illustrated by Figure 7,
which shows components C5, C6, and C7 being chopped by the 1-MHz clock, C4. The
dotted lines indicate where the edges of the components would be without
chopping. Note that C4 # C5 is the same as C5 shifted 1/4 cycle to the left.
This occurs when a component is chopped by another component at twice its
frequency.
In the chopping-disabled mode, no components are chopped until 1 kHz
(C14) and the remaining lower frequency components (C15 to C24) are reached.
The chopping component must be of the same or lower frequency than the clock
component, and it should be no lower than 16 kHz (C10). The chopping function
is handled by the ranging default software and can be overridden by directive
if necessary.
2.3.7 Other Parameters
There are four other parameters that must also be specified for
ranging operations. Their meaning and usage are briefly summarized below.
2.3.7.1 Tolerance
Tolerance is used to set the acceptable limit of the FOM -- an
estimate of the goodness of an acquisition, based on the P_r/N_0 measurement (see
Paragraph 2.4.3 for additional discussion).
Tolerance may be selected over the range of 0.0% to 100.0%. As an
example, if the tolerance is set to 0.0%, all range acquisitions will be
declared valid. Alternately, if the tolerance is set to 100.0%, all range
acquisitions will be declared invalid. A typical value set for tolerance is
99.9%. This value will flag acquisitions that have a 99.9% or better chance of
being good as valid, and the rest as invalid.
An acquisition is declared valid or invalid depending upon the
following criteria:
FOM >= Tolerance results Acquisition declared valid
in
FOM < Tolerance results Acquisition delcared invalid.
in
2.3.7.2 Servo
Servo is used to correct distortions of the data due to charged
particle effect using DRVID information (See Paragraph 2.4.3 for a discussion of
DRVID). When Servo is enabled, the local Doppler-corrected components will be
shifted back into phase with the received components. The correction is made by
setting a proper Servo value.
Figure 7. Chopping of C5, C6, and C7 (by C4)
(Figure omitted in text-only document)
Servo has a value between 0 and 1.0. It should be set to 1.0 with a
noiseless signal, but if the noise level is too high, no DRVID refinement is
possible and Servo should be set to 0. Note that if Servo is 1.0, the correction
is made immediately; however, if Servo is set to a fractional value between 0
and 1.0, that fraction of the correction will be done on any one DRVID
measurement.
2.3.7.3 Pipe
The Pipe parameter (for pipelining) specifies the number of range
acquisitions to be made. This parameter enables multiple measurements to be
initiated before the first measurement is completed. Only one acquisition is
made if Pipe is disabled. If it is enabled, range measurements will be made
until the total number of acquisitions reaches (2^15 - 1) or until the specified
number of acquisitions. In other words, the number of range acquisitions that
can be performed is between 1 and (2^15 - 1).
2.4 Range Measurement Process
The URA uses a reference frequency (denoted by F_66 in this document)
from the exciter to generate a sequence of square waves (or binary codes). This
code sequence is phase-modulated onto the uplink carrier beginning at the transmit time. The
measurement process begins at T_0 which is between 0 and 1 second before this
signal is received by the RRP, one RTLT later.
The RRP contains an identical coder that is driven by a reference
frequency (denoted by F_RNG in this document) that is derived from the received carrier
frequency but scaled to the corresponding uplink frequency as discussed in
paragraph 2.2. Thus, the receiver coder is able to provide a code sequence
that includes compensation for the frequency shift introduced by Earth-
spacecraft relative Doppler.
At T_0, the first (clock) component from the reciever coder is
correlated against the received signal to produce the correlation values V_I and
V_Q. The V_I s and V_Q s are used to compute the angle and amplitude of the
received code; hence, the phase and signal strength are
determined. The following paragraphs provide further detail.
The measurement of the phase (angle) displacement of the clock
provides the resolving capability of the range measurement (See Table 1). Once
the phase displacement is determined, the receiver coder is shifted by this
displacement amount to produce a zero-phase shift in the in-phase channel.
Since the remaining components are phase-coherent with the clock component, it
is only necessary to determine if each component is in or out of phase with the
previous component. This is done by integrating the V_I s and V_Q s for the time
T_2 specified during initialization. If each component is in phase, no action is necessary; if
one is out of phase, that component and the remaining components are shifted by
half its period. This process is repeated for each component. The sum of the
required shifts (plus the clock-phase shift) is the phase delay between the
transmitted and received signals, and the range is determined. The process is
illustrated in Figure 8.
2.4.1 Range Measurement Technique
The RRP measures two-way range, that is, the RTLT, by determining
the phase difference between the transmitted and received modulation. This
phase displacement (tau) is computed by the following expressions:
Sine-wave ranging:
tau = atan2 (SIGMA V_Q, SIGMA V_I), radians (16)
Square-wave ranging:
tau = SGN(SIGMA V_Q) x 1/4 x (1 - (SIGMA V_I)/(abs(SIGMA V_Q) + SIGMA V_I)), cycles. (17)
Figure 8. Component Acquisition Process
(Figure omitted in text-only document)
Notes:
1. Assume that the range to the spacecraft results in tau = tau_R and that the
range uncertainty is in the interval defined by C2 and C3.
2. Measurement of the phase offset of C1 indicates that the correlation
amplitude is not at a peak value. The receiver coder is shifted (delayed) to
bring the correlation value to a positive peak, A.
3. At A, the correlation function for C2 is at a negative peak; thus C2
is out of phase. The reference code is shifted by half the period of C2 (to
bring it into phase), arriving at B.
4. At B, C3 is out of phase with C2. The reference code is shifted by
half the period of C3, arriving at D.
5. The sum of the phase shifts required to bring all components into
phase is tau_R , the range measurement.
where
V_I and V_Q = the in-phase and quadrature correlation values
atan2(y,x)= the arctangent function that produces an angle in the proper quadrant
SGN(*) = | +1, * >= 0
| -1, * < 0
For ranging operations, the above tau of different dimensions are
converted to a measurement unit called the range units (RU). RUs have the
dimension of seconds and are defined as 1/16 of the period of the reference
frequency, that is
RU =1/16 x 1/F_66, s (18)
where F66 is the reference frequency, F66S or F66X as discussed earlier.
Using the above RU equation, one may convert the measurement obtained in RUs
to physical quantities such as time (nanoseconds) and distance (meters). For
example, if the F66 used in a range measurement is 66.000 MHz and suppose the
measurement obtained is 6,500,000 RU, then the equivalent RTLT delay is 6.155
ms, and the one-way distance is about 923,295 m.
2.4.2 P_r/N_0
The actual ranging power-to-noise spectral density (P_r/N_0) is
evaluated at the end of the integration of all in-phase and quadrature
correlation values for the clock. It combines ranging system performance with
receiver noise. This ratio is given by:
P_r/N_0 = 10log((Ranging Signal Power(P_s))/(Noise Power(P_n)) x Bandwidth(BW)), DB (19)
where, depending on a ranging operation, P_s is evaluated by two different expressions.
Sine-wave operation:
P_s = ((SUM(V_I, 1, N))^2 + (SUM(V_Q, 1, N))^2)/N^2 (20)
Square-wave operation:
P_s = (SUM(V_I, 1, N) + SUM(V_Q, 1, N))^2/N^2 (21)
where:
V_I and V_Q are the correlation values.
N is the total number of samples collected during the clock acquisition.
Noise power is estimated by adding the variances of the in-phase and
quadrature correlation samples:
P_n = Var_I + Var_Q , (22)
where: Var_x is the variance function:
Var_x = SUM(x^2, 1, N)/N - (SUM(x, 1, N))^2/N^2 (23)
where:
x represents the correlation sample V_I s and V_Q s
N is the number of samples. Finally, because P_n = N_0 x the process bandwith of the RRP,
it is necessary to multiply P_s/P_n by the process bandwidth (1 Hz) to put it in the form of P_r/N_0.
2.4.2 Figure of Merit
The FOM is a probability measure which estimates the chance of
successful acquisition of all lower frequency codes. The probability of
making at least one error in acquiring these codes is:
P_e = 1 - [1/2 + 1/2Erf(sqrt(P_r/N_0 x T_2))]^(n-1) (24)
where:
n = the number of components including the clock.
Erf(*) = the error function.
P_r/N_0 = the ranging power-to-noise ratio.
T_2 = the integration time for each of the lower frequency components, s.
Therefore, the probability P_c of getting all correct measurements is:
P_c = 1 - P_e (25)
FOM = 100 x P_c, percent (26)
The FOM is calculated following the clock phase measurement using the
measured P_r/N_0, the integration time T_2, and the number of lower-frequency
components. The FOM is a valid estimate only if conditions do not change. It
provides a reference by which a user may judge the validity of a range
measurement. Figures 9 to 11 show P_c versus P_r/N_0 for
various values of T_2 and n.
Figure 9. Figure of Merit, with T_2 = 5 sec for Various Frequency Components.
(Figure omitted in text-only document)
Figure 10. Figure of merit, with T_2 = 50 sec for Various Frequency Components.
(Figure omitted in text-only document)
Figure 11. Figure of merit, with T_2 = 500 sec for Various Frequency Components.
(Figure omitted in text-only document)
2.4.3 Differenced Range Versus Integrated Doppler
Differenced range versus integrated Doppler (DRVID) may be used to
calibrate the range observable and to study the electron content in the
transmission medium. For a given range observable, charged particles have the
effect of making the spacecraft appear further than its actual distance. As
the signal propagates through the charged-particle medium, the phase velocity
of the carrier increases by a certain quantity, while the group velocity of
the range code decreases by exactly the same quantity.
In the NSP era, DRVID is calculated from tracking data containing the
observed differences between the range measurements affected by the range-code
group velocity, and the delta range measurements derived from the Doppler
measurements influenced by the carrier-phase velocity. A more proper term for
this quantity is pseudo-DRVID (PDRVID); however, the traditional name will be
used in this article.
DRVID (t) = {[phi_u(t) - phi_d(t)]-[phi_u(t - T_cycle) - phi_d(t - T_cycle)]} (27)
- 26 * {r_1 * [theta_u(t) - theta_u(t - T_cycle)]
- r_2 * [theta_d(t) - theta_d(t - T_cycle)]} mod range ambiguity
where
phi_u(t) = uplink range phase, s
phi_d(t) = downlink range phase, s
theta_u(t) = uplink carrier phase, RU
theta_d(t) = downlink carrier phase, RU
T_cycle = anging cycle time, s
r_1 = exciter reference frequency/carrier frequency ratio
(either 1/32 or 221/(749 x 32) - see Paragraph 2.3)
r_2 = transponder turnaround ratio.
2.5 Ratio of Downlink Ranging Power to Total Power
For the type of currently used turn-around ranging channel, the
ratio of power in the fundamental ranging sidebands to the total signal power
in the downlink is a function of the uplink ranging signal-to-noise ratio. The
P_r/Pt ratio for two-way ranging is given as:
[P_r/P_t]_DN = 2*J_1^2[sqrt(2) * theta_DN sqrt(gamma_(RNG/UP)/(1 + gamma(RNG/UP)))] *
exp(- (theta^2_DN/(1 + gamma_(RNG/UP))) (28)
where:
[P_r/P_t]_DN = the ratio of power in fundamental ranging sidebands to total
signal power for downlink
J_1^2[*] = the Bessel function of the first kind of order one
theta_DN = the downlink ranging modulation index, radians rms
gamma_(RNG/UP) = the uplink ranging signal-to-noise ratio at the output of the
transponder's ranging channel filter, given by:
gamma_(RNG/UP) = 8/(pi)^2[P_r/N_0]_up * 1/B_RNG (29)
where:
[P_r/N_0]_UP = the ranging power to noise spectral density ratio at input to the
transponder's ranging channel filter, Hz
B_RNG = A typical value for B_RNG is 1.5 MHz.
Figure 12 is a plot of equation 28, with [P_r/P_t]_DN versus gamma_(RNG/UP) for
selected values of theta_DN. For deep space missions, the uplink ranging signal-to-noise ratio
is usually quite small, and the operating point lies on the steep curve on the
left side of Figure 12. In this case, equation 28 may be approximated as
follows:
[P_r/P_t]_DN ~= gamma_(RNG/UP) * theta_DN^2 * exp(-theta_DN^2), gamma_(RNG/UP) << 1 (30)
Figure 12. P_r/P_t as a Function of gamma_(RNG/DN) for Selected Values of
Modulation Index theta_DN
(Figure omitted in text-only document)
The presence of uplink noise feeding through onto the downlink has
two effects on ranging performance: loss of ranging power and interference.
Noise affects the ranging performance by dissipating valuable downlink power
from the fundamental ranging signal sidebands. This is characterized by the
above expressions for [P_r/P_t]_DN. Alternately, the potential exists for
noise to interfere with the fundamental ranging sidebands, causing degradation
to the ranging signal by raising its noise floor. For most deep space missions,
the latter effect is not considered to cause significant degradation for
two-way ranging measurements.
2.6 Range Corrections
The DTT range measurements include delays of equipment within the DSS
as well as those of the spacecraft. These delays must be removed in order to
determine the actual range referenced to some designated location at the
antenna. Figure 13 illustrates the end-to-end range measurement and identifies
the delays that must be removed before an accurate topocentric range can be
established. The DSN is responsible for providing three measurements to the
project. They are the DSS delay, the Z-correction, and the antenna correction.
Figure 13. DSS Reference S/C Reference Location Location
(Figure omitted in text-only document)
2.6.1 DSS Delay
The DSS delay is station and configuration dependent. It should be
measured for every ranging pass. This measurement is called precal for pre-track
calibration and postcal for post-track calibration. The former is done at the
beginning of a ranging pass; the latter is only needed when there is a change in
equipment configuration during the track or precal was not performed due to a
lack of time.
The delay is measured by a test configuration, which approximates
the actual ranging configuration. The signal is transmitted to the sky;
however, before reaching the feedhorn, a sample is diverted to a test
translator through a range calibration coupler. The test translator shifts the
signal to the downlink frequency, which is fed into the coupler. The signal
flows through the LNA to the DTT for calibration.
Figure 14 shows the signal path for a typical calibration of DSS
delay when the uplink and downlink are in the same frequency band. The heavy
lines identify the calibration path. When the uplink and downlink are in
different bands, the downlink signal from the test translator is coupled into
the receive path ahead of the LNA and as close to the feed as practical.
2.6.2 Z-Correction
The delay in the microwave components ahead of the coupler and the
airpath (the distance from the horn aperture plane to the subreflector, to the
antenna aperture plane, and finally to the antenna reference location) must be
included in the calibration. Also, the translator delay must be removed. A
measurement called "Z-correction" is made to obtain an adjusted DSS delay.
The Z-correction is given by the difference of two quantities: the
translator delay and the microwave plus air path delay. Figure 15 relates these
quantities to the physical structure of the antenna.
The test translator delay is measured by installing a zero delay
device (ZDD) in place of the test translator. Since the ZDD delay is measured
in the laboratory, the signal delay contributed by the test translator can be
calculated to a known precision. This measurement is made approximately twice
a year or when there are hardware changes in the signal path.
The microwave and air path delays are measured by physically
calibrating the microwave hardware components prior to installing them on the
antenna. The antenna aperture plane, the horn aperture plane, and an antenna
reference location are used to determine the actual air path delay as shown in
Figure 14. The antenna reference location is the perpendicular intersection of
the primary antenna axis with the plane of the secondary axis. Geocentric and
geodetic locations for the antenna reference location can be found in module
301.
2.6.3 Antenna Correction
An antenna correction is required when the antenna reference location
is not at a fixed location with respect to the Earth. Because the NSP ranging
equipment only is being installed at Azimuth-Elevation (Az-El) antennas that
have a fixed reference location, no antenna correction is required. The antenna
correction for the 26-m subnet antennas is described in Appendix A.
Figure 14. Typical DSS Delay Calibration
(Figure omitted in text-only document)
Figure 15. Measuring the Z-Correction
(Figure omitted in text-only document)
2.7 Error Contributions
The ground system, the media, and the spacecraft contribute errors to
range measurements. The error contributions of the media and spacecraft are
outside the scope of this document and have not been included.
The round-trip one-sigma delay error of the DSN ranging system over a
ranging pass has been estimated for the X-band system as 6.3 nanoseconds (about
0.95 meter one-way). The S-band one-sigma delay error has been estimated as 12.5
nanoseconds (about 1.9 meters one-way).
Table 2 provides a breakdown of long-term error contributions due to
calibration and errors inherent within the equipment of the various subsystems
that constitute the total ground system of the NSP-Era Ranging System.
Table 2. One-Sigma Range Error for NSP-Era Ranging System
Subsystem X-band S-band
Round- One-way Round- One-way
trip trip
Delay
Delay Distance (ns) Distance
(ns) (m) (m)
FTS 1.00 0.15 1.00 0.15
Receiver 2.00 0.30 2.00 0.30
Exciter and 1.33 0.20 5.33 0.80
Transmitter
Microwave and 2.33 0.35 2.33 0.35
Antenna
Uplink Ranging 2.00 0.30 2.00 0.30
Board
Downlink 2.00 0.30 2.00 0.30
Ranging Board
Cables 1.33 0.20 1.33 0.20
Calibration 2.66 0.40 2.66 0.40
Reserve 3.33 0.50 10.0 1.50
Root Sum Square 6.33 0.95 12.47 1.87
Appendix A
The Current DSN Ranging System
The current DSN ranging equipment has the same functional
characteristics as the equipment previously described but does not provide
optimum performance with the newer digital receivers. It is therefore being
replaced at the 70-m, the 34-m HEF, and all 34-m BWG stations except DSS 27.
This appendix describes the architecture and performance of the current
sequential ranging equipment in the 26-m subnet and at the 34-m HSB station, DSS
27. It also identifies the performance differences between the NSP ranging
equipment and the existing ranging equipment when it is used at the 70-m, the 34-
m HEF, and the 34-m BWG stations.
A1.0 System Description Using the Sequential Ranging Assembly
The DSS Tracking Subsystem (DTK) comprises two items of equipment,
the sequential ranging assembly (SRA) and the metric data assembly (MDA). This
equipment performs the range measurement, formats the radiometric data, and
sends it to the NAV at JPL. The NAV processes and provides the data to
projects. The Network Support Subsystem (NSS) provides radiometric predicts to
the DTK. Figure A-1 shows the current DSN ranging system configuration.
The SRA generates a sequence of square-wave frequencies (ranging code
components) that are modulated onto the uplink carrier by the exciter and
transmitted to the spacecraft. The spacecraft on-board transponder receives the
signal , demodulates and filters it, and remodulates it onto the downlink
carrier. The downlink is captured and amplified at the DSS, downconverted by
the RID, and received by either a multi-function receiver (MFR) or Block V
receiver (BVR). The SRA correlates the demodulated downlink signal with a
Doppler-modified replica of the transmitted codes using the same process as was
described earlier.
The SRA has two hardware interfaces with the exciter. The first
provides the reference frequency, F_66, from the exciter to the SRA. The second
supplies the square-wave ranging modulation signal derived from this reference
to the phase modulator in the exciter. The SRA also has two hardware interfaces
with the receiver. The first carries the received ranging codes while the
second provides a representation of the received Doppler. Each SRA has two
receive channels so there are actually two pairs of interfaces between the SRA
and the two receivers at each station. SRA channel 1 is normally used to
process S-band (or receiver 1) data and channel 2 is used to process X-band (or
receiver 2) data.
Figure A-1. Current DSN Ranging System
(FIgure omitted in text-only document)
At the 26-m Subnet stations and the 34-m HSB antenna, the received
ranging codes are provided to the SRA as a 10-MHz analog intermediate frequency
(IF) from the MFR and demodulated within the SRA. At stations employing the BVR
(the 70-m, the 34-m HEF, and the 34-m BWG stations), demodulation of the ranging
codes are done within the receiver and the ranging baseband signal is sent to
the SRA as digital data through an optical-fiber interface.
A2.0 Range Measurement Process Using the SRA
The SRA transmitter coder uses a reference frequency (denoted by
F_66 in this document) to generate a sequence of square waves (or binary
codes). This code sequence is phase-modulated onto the uplink carrier. The
measurement process begins at T_0 which is between 0 and 1 second before this
signal is received by the SRA one RTLT later.
Prior to the receive time, T_0, the SRA receiver coder is referenced to
the same F66 as the tramsnitter coder so it operates at the same frequency and
phase. At T_0, a scaled Doppler reference from the tracking receiver is
introduced to advance or retard the phase of the receiver coder. This has the
effect of adding the frequency shift introduced by Earth-spacecraft relative
Doppler to the receiver coder so the correlation can be accomplished. Having
aligned the receiver coder frequency to the frequecny of the received code, the
correlation to determine the phase of the received code proceeds by the same
process described in paragraph 2.4.
A3.0 Performance Differences
The performance of the SRA and the NSP-era ranging are slightly
different because of improvements incorporated into the new equipment and
interface incompatabilitese between the SRA and digital receivers in 70-m, the
34-m HEF, and the 34-m BWG stations and the SRA. The following paragraphs
summarize these differences.
A3.1 Integration Times
The SRA requires specification of the same three integration times as
discussed in paragraph 2.3.4; however, their calculation and recommendations for
selecting values are somewhat different.
A3.1.1 T_1
T_1, the total time used to integrate the correlation samples for the
clock component, is calculated by the equations provided in paragraph 2.3.4.1
with different constants. The modified expressions are:
Sine-wave operation:
T_1 = 1/56 x 1/F_c^2 x 1/(sigma^2(t)) x 1/(P_r/N_0), s (A-1)
Square-wave operation:
T_1 = 8/343 x 1/F_c^2 x 1/(sigma^2(t)) x 1/(P_r/N_0), s (A-2)
where
F_c = the clock frequency, Hz
sigma^2(t) = the desired variance of the RTLT measurements, s^2
P_r/N_o = the ranging signal to noise spectral density, Hz.
The above equations can be rewritten in terms of the uncertainty sigma(r)
in meters, by multiplying the uncertainty sigma(t) in seconds by the speed of light
and dividing by a factor of 2. This provides:
Sine-wave operation:
sigma(r) = sqrt(402/(F_c^2(MHz) x T_1 x P_r/N_0), m (A-3)
Square-wave operation:
sigma(r) = sqrt(523/(F_c^2(MHz) x T_1 x P_r/N_0), m (A-4)
where
F_c = the clock frequency, MHz
T_1 = the clock component integration time, s
P_r/N_o = the ranging signal to noise spectral density, Hz.
Note: The uncertainty s here is only due to thermal noise. Other
errors must be added to this to get the total uncertainty (see paragraph A5.0).
Figure A-2 plots integration time (T_1) as a function of P_r/N_o with sigma(r) as a
parameter for the SRA using sine-wave operation and a 1-MHz clock component.
For a desired sigma(r), the user may find the proper integration time, T_1, for an
estimated P_r/N_o (in dB-Hz). Figure A-3 is a similar graph for square-wave
operation using a 500-kHz clock component. This figure may also be used for lower
frequency square-wave clocks by recognizing that dividing Fc by 2 will result in
T_1, being multiplied by 4, etc.
Ranging is possible as long as the receiver remains in lock over the measurement
time. However, there is a practical lower limit for P_r/N_o (usually about -10
dB-Hz) determined by the combination of integration times (cycle time) and the
minimum number of range points needed by the project. See Cycle Time in
Paragraph 2.3.4.4 for further details. A P_r/N_o of -10
dB-Hz is also the recommended limit when the SRA is used with the Block V
Receiver because of inefficiencies in the interface between the two pieces of
equipment.
A3.1.2 T_2
T_2, the integration time for each of the lower frequency components,
is calculated by the equation provided in paragraph 2.3.4.2 (equation 9). The
figures provided there are repeated as figures A-4 through A-6 to emphasize the
recommendation that the SRA should not be operated at a P_r/N_o of less than -10
dB-Hz when using the Block V Receiver.
A3.1.3 T_3
T_2, the integration time for DRVID measurements, is selected by the
same reasoning discussed in paragraph 2.3.4.3 and is usually set at 7/8 x T_1,
rounded to the nearest integer.
A3.2 Other SRA Ranging Parameters
The other SRA ranging parameters are the same as required by NSP-era
ranging. This includes modulation index (paragraph 2.3.5), frequency chopping
(paragraph 2.3.6), tolerance (paragraph 2.3.7.1), servo (paragraph 2.3.7.2),
and pipe (paragraph 2.3.7.3).
A3.3 SRA Calculations
A3.3. Cycle Time
The cycle time calculated by the SRA uses the same algorithm as the NSP-era
ranging discussed in paragraph 2.3.4.3.
A3.3.2 P_r/N_o
The actual ranging power-to-noise spectral density (P_r/N_0) is
evaluated at the end of the integration of all in-phase and quadrature
correlation values for the clock by the same
proces that was described in paragraph 2.4.2. However, the process bandwidth
of the SRA is 5 Hz as P_r/N_0 is evaluated using pairs of 0.1-second long
correlation samples. Therefore, it is necessary to multiply Pn by the
reciprocal of 2 x 0.1 s, or 5 Hz, in order to put it in the form of P_r/N_0.
Figure A-2. Integration Time T_1 versus P_r/N_0, Clock Frequency F_c = 1 MHz,
for Sine-Wave ranging using the SRA
(Figure omitted in text-only document)
Figure A-3. Integration Time T_1 versus P_r/N_0, Clock Frequency F_c = 500 MHz,
for Sine-Wave ranging using the SRA
(Figure omitted in text-only document)
Figure A-4. Code Component Integration Time T_1 versus P_r/N_0 for various probabilities
of Error and n=5
(Figure omitted in text-only document)
Figure A-5. Code Component Integration Time T_1 versus P_r/N_0 for various probabilities
of Error and n=10
(Figure omitted in text-only document)
Figure A-6. Code Component Integration Time T_1 versus P_r/N_0 for various probabilities
of Error and n=20
(Figure omitted in text-only document)
A4.0 Range Corrections Using the SRA
The following paragraphs discuss the DSS delay and antenna
calibration when using the SRA. The Z-correction (paragraph 2.6.2) is the
same for both types of ranging equipment.
A4.1 DSS Delay
The DSS Delay is measured by the same technique as discussed in
paragraph 2.6.1; however, calibration path is different and is illustrated in
Figure A-7. This figure assumes the uplink and downlink signals are in the
same frequency band. When the uplink and downlink are at different
frequencies, the downlink signal from the Test Translator is coupled into the
receive path ahead of the LNA and as close to the feed as practical.
A4.2 Antenna Calibration
There are two types of structurally different antennas in the DSN.
They are the Azimuth-Elevation (Az-El) mount, and the X-Y mount. The first type
has an azimuth axis that perpendicularly intersects the elevation axis with the
result being that the antenna correction is equal to zero. The DSN 70-m, 34-m
HEF, 34-m BWG, and 34-m HSB antennas are of this type.
The X-Y antennas of the 26-m subnet have a primary axis and a
secondary axis that are offset from each other. This offset causes the
secondary axis (the Y-axis) to move relative to the Earth as the antenna
rotates and adjusts its elevation about the primary axis (the X-axis). The
change of distance is calculated by the following antenna correction
expression:
delta_(rho_A) = -6.706cos(theta), m (A-5)
where
theta = the angle of the Y-axis.
Figure A-7. Typical Range Calibration Signal Path for DSS Using SRA and MDA Ranging Equipment
A5.0 Error Contributions for Ranging Using the SRA
The round-trip one-sigma-delay error of the DSN ranging system over a
ranging pass has been estimated for the X-band system as 6.3 nanoseconds (about
1.0 m one-way). The S-band system error has been estimated as 14.5 nanoseconds
(about 2.2 m one-way).
Table A1 shows a breakdown of long-term error contributions due to
calibration and errors inherent within the equipment of the various subsystems
that constitute the total ground system using the SRA and MDA ranging equipment.
Table A-1. One-Sigma Range Error for SRA/MDA-Equipped Ranging System
Subsystem X-band S-band
Round- One-way Round- One-way
trip trip
Delay
Delay Distance (ns) Distance
(ns) (m) (m)
Frequency and 1.00 0.15 1.00 0.15
Timing
Receiver 2.67 0.40 2.67 0.40
Exciter and 1.33 0.20 5.33 0.80
Transmitter
Microwave and 2.33 0.35 2.33 0.35
Antenna
Tracking 0.67 0.10 0.67 0.10
Cables 1.33 0.20 1.33 0.20
Calibration 3.33 0.50 3.33 0.50
Reserve 3.33 0.50 12.47 1.87
Root Sum 6.30 0.95 14.52 2.18
Square
810-005, Rev. E
DSMS Telecommunications Link
Design Handbook
209
Open-Loop Radio Science
Effective November 30, 2000
Document Owner: Approved by:
----------------------- --------------------------
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Prepared by: Released by:
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Change Log
Rev Issue Date Affected Paragraphs Change Summary
Initial 1/15/2001 All All
Note to Readers
There are two sets of document histories in the 810-005 document, and these
histories are reflected in the header at the top of the page. First, the entire document is
periodically released as a revision when major changes affect a majority of the modules. For
example, this module is part of 810-005, Revision E. Second, the individual modules also
change, starting as an initial issue that has no revision letter. When a module is changed, a
change letter is appended to the module number on the second line of the header and a summary
of the changes is entered in the module's change log.
This module documents the new Radio Science Receivers that will become operational in the
year 2001 and the Ka-band capability at DSS 25. The equipment that was previously documented
in module RSS-10 of 810-005, Rev. D has been removed from the network.
Contents
Paragraph Page
1 Introduction ......................................................................................... 4
1.1 Purpose ............................................................................................ 4
1.2 Scope .............................................................................................. 4
2 General Information................................................................................... 4
2.1 Functions........................................................................................... 5
2.2 Hardware Configuration ............................................................................. 5
2.3 RSR Signal Processing .............................................................................. 7
2.4 RSR Signal Detection................................................................................ 7
2.5 RSR Operation ...................................................................................... 9
2.6 Data Delivery ..................................................................................... 11
2.6.1 Ancillary Data .................................................................................. 11
2.7 Performance ....................................................................................... 11
2.7.1 Frequency Stability.............................................................................. 11
2.7.2 Phase Noise...................................................................................... 13
2.7.3 Amplitude Stability ............................................................................. 14
2.8 Precision Telemetry Simulator...................................................................... 14
3 Proposed Capabilities................................................................................ 14
3.1 70-m X-band Uplink Implementation ................................................................. 14
Illustrations
Figure Page
1. Radio Science Receiving Equipment Configuration ..................................................... 6
2. Relationships Between RSR Processing Bands.......................................................... 10
Tables
Table Page
1. Supported Bandwiths and Resolutions with Resulting Data Rate......................................... 8
2. Radio Science Receiver Characteristics ............................................................. 12
3. Uplink and Downlink Allan Deviation Requirements ................................................... 15
4. Uplink and Downlink Phase Noise Requirements........................................................ 16
1 Introduction
1.1 Purpose
This module describes the capabilities and performance of the Deep
Space Network (DSN) Open-loop Radio Science equipment used for supporting
radio science (RS) experiments.
1.2 Scope
This module discusses the open-loop radio science receiving equipment
functions, architecture, operation, and performance. Although some RS
experiments require uplink support and closed-loop Doppler and ranging data,
this module emphasizes a description of the open-loop recording capability that
is used solely during radio science experiments. Details of the closed-loop
Doppler tracking system can be found in module 203, 34-m and 70-m Receiver
Doppler. Details of the uplink functions can be found in the 70-m, 34-m High
Efficiency (HEF), and 34-m Beam Waveguide (BWG) telecommunications interface
modules 101, 103, and 104.
2 General Information
Radio science experiments involve measurements of small changes in the
phase, frequency, amplitude, and polarization of the radio signal propagating
from an interplanetary spacecraft to an Earth receiving station. By properly
analyzing these data, investigators can infer characteristic properties of the
atmosphere, ionosphere, and planetary rings of planets and satellites, measure
gravitational fields and ephemeredes of planets, monitor the solar plasma and
magnetic fields activities, and test aspects of the theory of general
relativity. Details of the Radio Science System applications may be found in the
JPL Publication 80-93, Rev. 1, written by S.W. Asmar and N.A. Renzetti, titled:
The Deep Space Network as an Instrument for Radio Science Research.
2.1 Functions
The functions of the DSN with respect to conducting radio science
experiments can be summarized as follows:
-Providing an uplink carrier signal to the spacecraft with a pure spectrum,
including low phase noise and stable frequency.
-Acquisition, down conversion, digitization, and recording of the downlink carrier
with minimal degradation to its frequency, phase, and amplitude stability.
-Providing assurance that the expected signals are being acquired and
recorded.
2.2 Hardware Configuration
All radio science experiments require use of the antenna, microwave,
antenna-mounted receiving, and frequency and timing equipment at the stations.
They also require the Ground Communications Facility (GCF) to deliver the data
from the stations to users and the Advanced Multi-mission Operations System
(AMMOS) at JPL, where experiments are monitored. DSN stations are designed to
meet radio science requirements for stability. However, one of the beam
waveguide stations at the Goldstone Deep Space Communications Complex (DSCC),
DSS 24, is not equipped with a high-quality frequency distribution system and is
not recommended for radio science applications. A block diagram of the open-loop
radio science receiving capability is shown in Figure 1.
The receiving equipment on each DSN antenna produces one or more
intermediate frequency (IF) signals with a nominal center frequency of 300 MHz
and a bandwidth that depends on the microwave and low noise amplifier equipment
on the antenna as described in modules 101, 103, and 104. These IF signals are
routed to a distribution amplifier (not shown in Figure 1) that provides
multiple copies of each signal for use by the Radio-science Receivers (RSRs),
the telemetry and tracking receivers, and other equipment in the signal
processing center (SPC). One copy of each signal is provided to the RSR IF
Switch that further divides and amplifies it with the result being that any of
the RSR channels can be connected to any antenna IF signal.
There are two dedicated RSRs at the Goldstone Deep Space
Communications Complex (DSCC) and one at the Canberra and Madrid DSCCs. Each
complex also has an online spare that is shared with other functions including
very-long baseline Interferometry (VLBI). Each RSR contains two channels however
the design of the system software is such that, from the user's viewpoint, each
RSR channel can be considered to be an independent open-loop receiver.
Figure 1. Radio Science Receiving Equipment Configuration
(Figure omitted in text-only document)
2.3 RSR Signal Processing
The IF signal selected by the RSR IF Switch is fed to the Digitizer
(DIG) where it is filtered to limit its bandwidth to the range of 265-375 MHz
centered at 320 MHz. This corresponds to a received frequency range of
2,265-2,375 MHz at S-band, 8,365-8,475 MHz at X-band, and 31,965-32,075 MHz at
Ka-band. However, the actual received frequency range will depend on the
characteristics of the equipment on the selected antenna. The filtered signal is
downconverted to a center frequency of 64 MHz and digitized at 256 MHz with an 8-
bit resolution. The resultant data are fed to the Digital Downconverter (DDC)
that selects any 16-MHz bandwidth from the original bandpass with a resolution
of 1 MHz and downconverts it to baseband in the form of a 16-Ms/s, 8-bit,
complex data stream.
Baseband processing provides up to four subchannel filters to select
frequency bands of interest for recording. The number of available filters
depends on the selected bandwidths that can be broadly categorized as
Narrowband, Medium Band, or Wideband. The following selection of filters is
available:
-4 Narrowband
-2 Narrowband and 1 Medium Band
-2 Medium Band
-1 Wideband
The filters are specified by their bandwidths, the desired resolution
(bits/sample) and an offset from the predicted sky frequency predict file. This
frequency predict file is created by the DSN network support function and
contains the spacecraft frequency altered by spacecraft trajectory and Earth-
rotation. Table 1 lists the supported filter bandwidths and resolutions and
gives the resultant data rate for each combination. Figure 2 shows the
relationship between the frequency bands within the RSR.
2.4 RSR Signal Detection
Because the RSR is an open-loop receiver, it does not have a
mechanism to align its passband to (establish lock with, or track) the received
signal. Instead, it relies on predicts to position its passband. This creates a
risk that a predict error might result in the wrong portion of the received
spectrum being processed. To assist in recognizing this, the RSR analyzes the
data in each subchannel and provides a detected signal indication on the main
display for that subchannel
In addition to the detected signal indication, the RSR provides a
frequency-domain representation of the bandpass being recorded in each RSR
subchannel using a Fast-Fourier Transform (FFT). Characteristics of the FFT
such as number of points, averaging, and update rate are under user control.
Table 1. Supported Bandwiths and Resolutions with Resulting Data Rate
Category Bandwidth Resolution Data Rate (b/s)
(b/sample)
Narrowband 1 kHz 16 32,000
2 kHz 16 64,000
4 kHz 16 128,000
8 kHz 16 256,000
16 kHz 16 512,000
25 kHz 16 800,000
50 kHz 16 1,600,000
100 kHz 16 3,200,000
1 kHz 8 16,000
2 kHz 8 32,000
4 kHz 8 64,000
8 kHz 8 128,000
16 kHz 8 256,000
25 kHz 8 400,000
50 kHz 8 800,000
100 kHz 8 1,600,000
Medium Band 250 kHz 16 8,000,000
500 kHz 16 16,000,000
250 kHz 8 4,000,000
500 kHz 8 8,000,000
1 MHz 8 16,000,000
250 kHz 4 2,000,000
500 kHz 4 4,000,000
1 MHz 4 8,000,000
2 MHz 4 16,000,000
Table 1. Supported Bandwiths and Resolutions with Resulting Data Rate (Continued)
Category Bandwidth Resolution Data Rate (b/s)
(b/sample)
Medium Band 250 kHz 2 1,000,000
(Continued)
500 kHz 2 2,000,000
1 MHz 2 4,000,000
2 MHz 2 8,000,000
4 MHz 2 16,000,000
250 kHz 1 500,000
500 kHz 1 1,000,000
1 MHz 1 2,000,000
2 MHz 1 4,000,000
4 MHz 1 8,000,000
Wideband 8 MHz 2 32,000,000
8 MHz 1 16,000,000
16 MHz 1 32,000,000
2.5 RSR Operation
The radio science equipment operates in both a link-assigned and a
stand-alone mode. In the link-assigned mode, the Network Monitor and Control
(NMC) function receives monitor data from the RSR for incorporation into the
data set for tracking support and provides a workstation from which the RSR can
be operated. RSRs that are not assigned to a link may be operated in a stand-
alone mode without interference to any activities in process at the complex.
Monitor data is not forwarded to the NMC by RSRs operating in the stand-alone
mode.
The RSR employs a client-server architecture where each RSR channel
acts as a server capable of accepting connections from up to five users
operating the radio science client software at any time. In the link-assigned
mode, one of these five clients is the NMC workstation. The RSR does not
recognize any client as being superior to the others so it is up to the user to
assign responsibility for control to one client with the other clients operating
in a passive mode. One RSR client is required for each RSR channel being
controlled or observed. Thus, a complex radio science experiment involving four
RSR channels would require four RSR clients at the control point.
Figure 2. Relationships Between RSR Processing Bands
(Figure omitted in text-only document)
All functions of the RSR may be performed from the RSR client in real
time. Of special interest to the RS experimenter are the ability to adjust
(slew) the predicted frequency profile, to slew the individual subchannel
frequencies, to adjust FFT parameters, and to enable or disable recording for
each subchannel.
2.6 Data Delivery
When recording is enabled, baseband samples and ancillary
information, discussed below, are formatted into a file of data blocks and
stored on disk drives for delivery to JPL or other users. A separate data file
is created for each subchannel. Data delivery is normally via the Reliable
Network System (RNS). Data also may be obtained via File Transfer Protocol
(FTP) or Digital Linear Tape (DLT) cartridges. The format is the same
independent of the method of delivery.
2.6.1 Ancillary Data
The following ancillary data are included as a header for each data
block. A detailed description of the data blocks is contained in TMOD Document
820-013, module 0159.
-Data record version
-Subchannel identification
-Time tag for first sample in block
-Station and pass identification
-Spacecraft identification
-Receiver configuration
2.7 Performance
The principal characteristics of the RSRs are summarized in Table 2.
In addition, radio science experiments are influenced by the overall stability
of equipment at the stations. The following sections provide information on the
techniques used to validate RS equipment stability.
2.7.1 Frequency Stability
Long-term frequency stability tests are conducted with the exciter/
transmitter equipment and the Radio Science open-loop receiving equipment. An
uplink signal generated by the exciter is translated at the antenna to a
downlink frequency. The downlink signal is passed through the RF-IF
downconverter at the antenna and into the RSR. In doing this test, however,
instability in the frequency and timing equipment and the mechanical vibrations
of the antenna are not included. This is because frequency and timing
instability is cancelled out, while the mechanical vibrations of the antenna are
not present in these data. Measurements of these items can however be obtained
via other means, making it possible to provide an estimate of the
Table 2. Radio Science Receiver Characteristics Table 2. Radio Science Receiver
Characteristics (Continued)
Parameter Value Remarks
Number of Channels Note: Any channel may be connected
to any received spectrum
Goldstone 4 2 additional channels are available
shared with other applications
Canberra and Madrid 2 2 additional channels are available
shared with other applications
Frequency Ranges Covered
At RSR Input (MHz) 265 - 375
Referenced to L-band 1,645 -1,755 L-band receive capability at 70-m
(MHz) subnet is 1,628-1,708 MHz
Referenced to S-band 2,265 - 2,375 S-band downlink allocation is
(MHz) 2,200-2,290 MHz for Earth orbiter
application and 2,290-2,300 MHz for
deep space applications
Referenced to X-band 8,365 - 8,475 X-band downlink allocation is
(MHz) 8,400-8,450 MHz for deep space
application and 8,450-8,500 MHz for
Earth orbiter applications
IF Attenuation
Range (dB) 0 - 31.5
Resolution (dB) 0.5
Doppler Compensation
Maximum Doppler Shift 30 At all downlink frequencies
(km/s)
Maximum Doppler Rate 17 At all downlink frequencies
(m/s2)
Maximum Doppler 0.3 At all downlink frequencies
Acceleration (m/s3)
Maximum Tuning Error 0.5 At all downlink frequencies
(Hz)
Manual Offset (MHz) -8.0 to +8.0
Baseband Bandwidth (MHz) 16
Parameter Value Remarks
Baseband Resolution 1 Positioning of baseband within
(MHz) IF or RF bandwidth
Number of Subchannels 1 - 4 Configuration depends on data
Available for each RSR volume.
Subchannel Tuning
Tuning (MHz) +/-8 From center of baseband
Resolution (Hz) <1
Recording Bandwidths See Table 2 for exact values.
Narrowband (NB), kHz 1 - 100 1 - 4-subchannels
Medium Band (MB), kHz 250 - 4,000 2 or 1 with 2 NB subchannels
Wideband (WB), MHz 8 or 16 NB and MB subchannels are not
available
Resolutions 16 - 1 Depends on selected bandwidth.
(bits/sample) See Table 2 for available
resolutions.
Time Tagging
Resolution (10^-6 s) 1
Accuracy (10^-6 s) 1 With respect to station clock
Signal Detection Display 1 for each subchannel being
recorded
Number of points in FFT 100 - 4096 Default is 1000
Spectra Averaging 1 - 100 Default is 10
FFT Interval (s) 1 - 10,000 Default is 10
overall frequency stability of the stations. The long-term frequency stability
is presented in terms of the Allan deviation over a specified integration time.
Table 3 shows uplink and downlink Allan deviation requirements for the 34-m HEF,
34-m BWG, and 70-m antennas. Repeated testing has always produced estimates
better than these requirements.
2.7.2 Phase Noise
Phase stability (Spectral Purity) testing characterizes stability
over very short integration times. The region of the frequency band where phase
noise measurements are performed can be as far as 10 kHz off the carrier
frequency. Such measurements are reported in dB relative to the carrier (dBc),
in a 1-Hz band at a specified distance from the carrier. Table 4 contains the
required phase noise levels, at specified offsets, for the 34-m HEF, 34-m BWG,
and 70-m subnets. As is the case with frequency stability measurements,
repeated testing ensures these requirements are not exceeded.
2.7.3 Amplitude Stability
Amplitude stability tests measure the amplitude fluctuations produced
by the open-loop receiving system relative to a constant (mean) amplitude input
signal. The amplitude stability performance is specified in terms of a threshold
on the amplitude fluctuations relative to the mean amplitude, and the
corresponding probability that such fluctuations will not exceed such a
threshold. An analysis indicates that 99.7% of the time, the amplitude stability
at the 70-m, 34-m HEF, and 34-m BWG stations at S- and X-bands is less than 0.2
dB including the gain variation due to antenna pointing errors.
2.8 Precision Telemetry Simulator
The Precision Telemetry Simulator (PTS) is an external device that
provides IF test signals for performance verification of the radio science
equipment. Its signals are generated in the digital domain and subsequently
converted to analog, with signal conditions driven from predicts. At least two
simulated signals can be generated, each having its own characteristics in terms
of Doppler and signal level, etc. The PTS signals are injected into the RSR via
the RSR IF Switch.
3 Proposed Capabilities
The following paragraphs discuss capabilities that have not yet been
implemented by the DSN but have adequate maturity to be considered for
spacecraft mission and equipment design. Telecommunications engineers are
advised that any capabilities discussed in this section cannot be committed to
except by negotiation with the Telecommunications and Mission Operations
Directorate (TMOD) Plans and Commitments Program Office.
3.1 70-m X-band Uplink Implementation
The 70-m X-band uplink implementation that has been completed at DSS
14 and DSS 43 will be extended to DSS 63. As a result, all 70-m stations will
have the same capabilities and performance as described for DSS 14 and 43 in
Tables 2, 3, and 4.
Table 3. Uplink and Downlink Allan Deviation Requirements Table 4. Uplink and
Downlink Phase Noise Requirements
Averaging Time, s Allan Deviation
1 10 100 1000
Station and Band
34-m HEF
X-band U/L 1.0x10^-12 1.1x10^-13 4.5x10^-15 4.3x10^-15
S-band D/L 4.1x10^-13 7.2x10^-14 9.1x10^-15 5.3x10^-15
X-band D/L 4.0x10^-13 4.9x10^-14 5.3x10^-15 4.7x10^-15
34-m BWG
S-band U/L(DSS 24,34,54) 1.0x10^-12 1.1x10^-13 4.5x10^-15 4.3x10^-15
X-band U/L(DSS 25,26,34,54) 1.0x10^-12 1.1x10^-13 4.5x10^-15 4.3x10^-15
S-band D/L(DSS 34,54) 4.1x10^-13 7.2x10^-14 9.1x10^-15 5.3x10^-15
X-band D/L(DSS 25,26,34,54) 4.0x10^-13 4.9x10^-14 5.3x10^-15 4.7x10^-15
Ka-band U/L (DSS 25) No Rqmt. No Rqmt. 1.1x10^-14 2.1x10^-15
Ka-band D/L (DSS 25) 1.3x10^-13 7.5x10^-14 6.8x10^-15 2.2x10^-15
70-m
S-band U/L 1.5x10^-12 2.3x10^-13 1.1x10^-14 1.1x10^-14
X-band U/L (DSS 14, 43) 1.5x10^-12 2.3x10^-13 1.1x10^-14 1.1x10^-14
S-band D/L 4.1x10^-13 7.2x10^-14 9.1x10^-15 5.3x10^-15
X-band D/L 4.0x10^-13 4.9x10^-14 5.3x10^-15 4.7x10^-15
Offset from Carrier, Hz Phase Noise, dBc
1 10 100 10 k
Station and Band
34-m HEF
X-band U/L -52.3 -61.8 -65.9 -65.9
S-band D/L -62.8 -72.2 -76.7 -76.7
X-band D/L -51.5 -60.9 -65.5 -65.5
34-m BWG
S-band U/L (DSS 24, 34, -63.5 -72.5 -77.1 -77.1
54)
X-band U/L (DSS 25, 26, -52.3 -61.8 -65.9 -65.9
34, 54)
S-band D/L (DSS 34, 54) -62.8 -72.2 -76.8 -76.8
X-band D/L (DSS 25, 26, -51.6 -61.0 -65.5 -65.5
34, 54)
X-band D/L (DSS 25) -59.7 -65.6 -66.0 -66.0
Ka-band D/L (DSS 25) -55.2 -63.7 -64.0 -64.0
70-m
S-band U/L -63.5 -72.5 -77.1 -77.1
X-band U/L (DSS 14, 43) -52.3 -61.8 -65.9 -65.9
S-band D/L -62.8 -72.2 -76.7 -76.7
810-005, Rev. E
DSMS Telecommunications Link
Design Handbook
301
Coverage and Geometry
Effective November 30, 2000
Document Owner: Approved by:
----------------------- -----------------------
R.W. Sniffin Date A. Kwok Date
Uplink Tracking and Command Service
Systems Development Engineer
Released by:
[Signature on file in TMOD Library]
------------------------
DSMS Document Release Date
Change Log
Rev Issue Date Affected Paragraphs Change Summary
Initial 1/15/2001 All All
Note to Readers
There are two sets of document histories in the 810-005 document, and these
histories are reflected in the header at the top of the page. First, the entire document is
periodically released as a revision when major changes affect a majority of the modules. For
example, this module is part of 810-005, Revision E. Second, the individual modules also
change, starting as an initial issue that has no revision letter. When a module is changed, a
change letter is appended to the module number on the second line of the header and a summary
of the changes is entered in the module's change log.
This module is essentially the same as 810-005, Rev. D, module GEO-10,
Rev. E. Information relating to decommissioned antennas has been removed, coverage charts
have been revised to reflect new capabilities, and a significant uplink coverage restriction at the
DSS 54 station is documented.
Contents
Paragraph Page
1 Introduction ......................................................................................... 6
1.1 Purpose............................................................................................. 6
1.2 Scope .............................................................................................. 6
2 General Information .................................................................................. 6
2.1 Station Locations................................................................................... 6
2.1.1 Antenna Reference Point .......................................................................... 6
2.1.2 IERS Terrestrial Reference Frame.................................................................. 8
2.1.2.1 ITRF Coordinates ............................................................................... 9
2.1.2.2 ITRF Site Velocities ........................................................................... 9
2.1.3 Geocentric Coordinates............................................................................ 9
2.1.4 Geodetic Coordinates.............................................................................. 9
2.2 Coverage and Mutual Visibility..................................................................... 15
2.2.1 Use of Transmitters Below Designated Elevation Limits ........................................... 15
2.2.1.1 Spacecraft Emergencies......................................................................... 15
2.2.1.2 Critical Mission Support....................................................................... 15
2.2.2 Mechanical Limits on Surveillance Visibility .................................................... 15
2.2.2.1 Azimuth-Elevation Antennas..................................................................... 16
2.2.2.2 X-Y Antennas .................................................................................. 16
2.2.2.3 Tilt-Azimuth-Elevation Antennas ............................................................... 16
2.2.3 Coverage Charts.................................................................................. 16
2.2.3.1 70-m Subnet Receive Coverage of Planetary Spacecraft .......................................... 16
2.2.3.2 70-m Subnet Transmit Coverage of Planetary Spacecraft.......................................... 17
2.2.3.3 34-m HEF Subnet Receive Coverage of Planetary Spacecraft ...................................... 17
2.2.3.4 34-m HEF Subnet Transmit Coverage of Planetary Spacecraft ..................................... 17
2.2.3.5 34-m BWG Antennas Receive Coverage of Planetary Spacecraft .................................... 18
2.2.3.6 34-m BWG Antennas Transmit Coverage of Planetary Spacecraft ................................... 18
2.2.3.7 26-m Subnet Receive Coverage of Earth Orbiter Spacecraft ...................................... 18
2.2.3.8 26-m Subnet Transmit Coverage of Earth Orbiter Spacecraft ..................................... 18
2.2.3.9 34-m BWG Antennas Receive Coverage of Earth Orbiter Spacecraft ................................ 18
2.2.3.10 34-m BWG Antennas Receive Coverage of Earth Orbiter Spacecraft ............................... 18
2.2.3.11 11-m Subnet Receive Coverage.................................................................. 19
2.2.4 Horizon Masks and Antenna Limits ................................................................ 19
3 Proposed Capabilities................................................................................ 19
3.1 70-m X-band Uplink Implementation ................................................................. 19
3.2 34-m BWG Ka-band Implementation ................................................................... 19
Appendix A References ................................................................................. 49
Illustrations
Figure Page
1. ITRF Cartesian and Geocentric Coordinate System Relationships ...................................... 10
2. DSN 70-m Subnet Receive Coverage, Planetary Spacecraft ............................................. 19
3. DSN 70-m Subnet Transmit Coverage, Planetary Spacecraft............................................. 20
4. DSN 34-m HEF Subnet Receive Coverage, Planetary Spacecraft.......................................... 21
5. DSN 34-m HEF Subnet Transmit Coverage, Planetary Spacecraft ........................................ 22
6. DSN 34-m BWG Antennas Receive Coverage, Planetary Spacecraft........................................ 23
7. DSN 34-m BWG Antennas Transmit Coverage, Planetary Spacecraft ...................................... 24
8. DSN 26-m Subnet Receive Coverage, Earth Orbiter Spacecraft ......................................... 25
9. DSN 26-m Subnet Transmit Coverage, Earth Orbiter Spacecraft ........................................ 26
10. DSN 34-m BWG Antennas Receive Coverage, Earth Orbiter Spacecraft................................... 27
11. DSN 34-m BWG Antennas Transmit Coverage, Earth Orbiter Spacecraft ................................. 28
12. DSN 11-m Subnet Earth Orbiter and Planetary Receive Coverage ...................................... 29
13. DSS 14 Hour-Angle and Declination Profiles and Horizon Mask........................................ 30
14. DSS 15 Hour-Angle and Declination Profiles and Horizon Mask........................................ 31
15. DSS 16 X-Y Profiles and Horizon Mask .............................................................. 32
16. DSS 23 Hour-Angle and Declination Profiles and Horizon Mask........................................ 33
17. DSS 24 Hour-Angle and Declination Profiles and Horizon Mask........................................ 34
18. DSS 25 Hour-Angle and Declination Profiles and Horizon Mask........................................ 35
19. DSS 26 Hour-Angle and Declination Profiles and Horizon Mask........................................ 36
Figure Page
20. DSS 27 Hour-Angle and Declination Profiles and Horizon Mask........................................ 37
21. DSS 33 Hour-Angle and Declination Profiles and Horizon Mask........................................ 38
22. DSS 34 Hour-Angle and Declination Profiles and Horizon Mask........................................ 39
23. DSS 43 Hour-Angle and Declination Profiles and Horizon Mask........................................ 40
24. DSS 45 Hour-Angle and Declination Profiles and Horizon Mask........................................ 41
25. DSS 46 X-Y Profiles and Horizon Mask .............................................................. 42
26. DSS 53 Hour-Angle and Declination Profiles and Horizon Mask........................................ 43
27. DSS 54 Hour-Angle and Declination Profiles and Horizon Mask........................................ 44
28. DSS 63 Hour-Angle and Declination Profiles and Horizon Mask........................................ 45
29. DSS 65 Hour-Angle and Declination Profiles and Horizon Mask........................................ 46
30. DSS 66 X-Y Profiles and Horizon Mask .............................................................. 47
Tables
Table Page
1. DSN Antenna Types.................................................................................... 7
2. ITRF93 Coordinates for DSN Stations ................................................................ 11
3. ITRF93 Site Velocities for DSN Stations ............................................................ 12
4. Geocentric Coordinates for DSN Stations ............................................................ 13
5. Geodetic Coordinates for DSN Stations............................................................... 14
6. Approximate Cable Wrap Limits for Azimuth-Elevation Antennas........................................ 17
1 Introduction
1.1 Purpose
This module describes the geometry and surveillance visibility
provided by the DSN for support of spacecraft telecommunications.
1.2 Scope
This module provides the Deep Space Network (DSN) station coordinates
that are required for spacecraft navigation and to locate the stations with
respect to other points on the Earth's surface. Coverage charts are provided to
illustrate areas of coverage and non-coverage from selected combinations of
stations for spacecraft at selected altitudes. Horizon masks are included so
the effects of terrain masking can be anticipated.
2 General Information
2.1 Station Locations
The following paragraphs discuss the important concepts relating to
establishing the location of the DSN antennas.
2.1.1 Antenna Reference Point
The coordinates provided by this module refer to a specific point on
each antenna. For antennas where the axes intersect, the reference point is the
intersection of the axes. For antennas for which the axes do not intersect, the
reference point is the intersection of the primary (lower) axis with a plane,
perpendicular to the primary axis, and containing the secondary (upper) axis.
Table 1 lists the DSN antennas by type and provides the axis offset where
appropriate. The effect of this offset on the range observable is discussed in
module 203 of this handbook.
The 11-m antennas are unique in that the azimuth axis is tilted from
the local vertical by a 7-degree wedge that is rotated to a position with
respect to north called the "train angle" before the start of each track. This
causes the station location to be displaced away from the train angle along a
circular path having a radius equal to the axis offset. The vector
(delta_r_sub_b), which must be added to the station coordinates to compensate
for this effect, can be derived from the train angle that is supplied to the
user as part of the tracking data (see module 302) and the north and east
station vectors (N and E) which are functions of the station geodetic coordinates.
Table 1. DSN Antenna Types
Antenna Type Station Identifiers Primary and Secondary Axis Offset
Axes
70-m 14, 43, 63 Az/El 0
34-m High Efficiency 15, 45, 65 Az/El 0
(HEF)
34-m Beam Waveguide 24, 25, 26, 34, 54 Az/El 0
(BWG)
34-m High-speed Beam 27, 28* Az/El 1.83 m
Waveguide (HSB)
26-m 16, 46, 66 X/Y 6.706 m
11-m OVLBI 23, 33, 53 Tilt/Az/El 0.391 m
Az/El Antenna's azimuth plane is tangent to the Earth's surface, and antenna at 90-degrees
elevation is pointing at zenith. X/Y Primary axis (X) is aligned horizontally in an east-
west (26-m antennas) or north-south (9-m antenna) direction. Secondary axis is aligned
vertically in a north-south (26-m antennas) or east-west (9-m antenna) plane. Tilt/Az/El
The azimuth axis of the Az/El mount is tilted to avoid an overhead keyhole. The direction
of tilt is fixed for each pass and results in an apparent shift in the actual station
location from the specified station location.
* DSS 28 is not presently in service.
delta r_b = -0.391cos(sigma)N -0.391sin(sigma)E (1)
where
sigma = the train angle
N = [ -sin(phi_g)cos(lambda)] (2)
[ -sin(phi_g)sin(lambda)]
[ cos(phi_g) ]
E = [-sin(lambda)] (3)
[-cos(lambda)]
[ 0 ]
phi_g = Station Geodetic Latitude (Table 5)
lambda = Station Longitude
2.1.2 IERS Terrestrial Reference Frame
To use station locations with sub-meter accuracy, it is necessary to
clearly define a coordinate system that is global in scope as opposed to the
regional coordinate systems referenced in previous editions of this document.
The International Earth Rotation Service (IERS) has been correlating station
locations from many different services and has established a coordinate frame
known as the IERS Terrestrial Reference Frame (ITRF). The IERS also maintains
a celestial coordinate system and coordinates delivery of Earth-orientation
measurements that describe the motion of station locations in inertial space.
The DSN has adopted the IERS terrestrial system to permit its users to have
station locations consistent with widely available Earth-orientation
information.
The IERS issues a new list of nominal station locations each year, and
these locations are accurate at the few-cm level. At this level of accuracy,
one must account for ongoing tectonic plate motion (continental drift), as well
as other forms of crustal motion. For this reason ITRF position coordinates are
considered valid for a specified epoch date, and one must apply appropriate
velocities to estimate position coordinates for any other date. Relative to the
ITRF, even points located on the stable part of the North American plate move
continuously at a rate of about 2.5 cm/yr.
The coordinates in this module are based on the 1993 realization of
the ITRF, namely ITRF93, documented in IERS Technical Note 18 (1). ITRF93 was
different from earlier realizations of the ITRF in that it was defined to be
consistent with the Earth Orientation Parameters (EOP) distributed through
January 1, 1997. Earlier realizations of the ITRF were known to be inconsistent
(at the 1-3 cm level) with the Earth orientation distributions.
After ITRF93 was published, the IERS decided to improve the accuracy
of the EOP series and make it consistent with the ITRF effective January 1,
1997. This date was chosen because it enabled a defect in the definition of
universal time to be removed at a time when its contribution was zero. In
anticipation of this change, ITRF94 and ITRF95 were made consistent with the
pre-ITRF93 definition of the terrestrial reference frame, and all prior EOP
series were recomputed in accordance with the new system.
Until this change is fully adopted by the Earth-orientation community,
the DSN is delivering Earth-orientation calibrations to navigation teams that
are consistent with the earlier definition and using the ITRF93 reference frame.
Users interested in precise comparison with other systems should keep in mind
the small systematic differences.
2.1.2.1 ITRF Coordinates
Figure 1 illustrates the ITRF coordinates and the relationship between the ITRF
coordinates and geocentric coordinates discussed below. The Cartesian
coordinates of the DSN station locations in the ITRF93 reference system are
provided in Table 2. Table 2 also gives the characteristic position
uncertainty for horizontal and vertical components.
2.1.2.2 ITRF Site Velocities
The locations given in Table 2 are for the epoch 1993.0. To
transform these locations to any other epoch, the site velocities should be
used. Table 3 gives the ITRF93 site velocities for the DSN stations, in both
Cartesian and east-north-vertical components.
2.1.3 Geocentric Coordinates
Geocentric coordinates are used for spacecraft tracking. They relate
the station location to the Earth's center of mass in terms of the geocentric
radius and the angles between the station and the equatorial and hour angle
planes. Geocentric coordinates for the DSN stations are provided in Table 4.
2.1.4 Geodetic Coordinates
Locations on the Earth's surface are defined with respect to the
geoid. That is, the surface around or within the Earth that is normal to the
direction of gravity at all points and coincides with mean sea level in the
oceans. The geoid is not a regular surface because of variations in the Earth's
gravitational force. To avoid having to make computations with respect to this
non-mathematical surface, computations are made with respect to an ellipsoid
having a semi-major (equatorial) axis and semi-minor (polar) axis that provides
a best fit to the geoid in the area of interest. The ellipsoid is uniquely
defined by specifying the equatorial radius and the flattening (that is, the
amount that the ellipsoid deviates from a perfect sphere). The relationship
between the polar and equatorial axes is given by the following expression:
(polar axis) = (equatorial axis) x (1 - flattening). (4)
Once the Cartesian coordinates (x, y, z) are known, they can be
transformed to geodetic coordinates in longitude, latitude, and height with
respect to an ellipsoid (lambda, phi, h) by the following noniterative method
(Reference 2):
Figure 1. ITRF Cartesian and Geocentric Coordinate System Relationships
(Figure omitted in text-only document)
Table 2. ITRF93 Coordinates for DSN Stations Table 3. ITRF93 Site Velocities for DSN
Stations
Antenna Cartesian Coordinates Uncertainty
Name Description x(m) y(m) z(m) h(m) v(m)
DSS 13 34-m R & D -2351112.491 -4655530.714 +3660912.787 0.04 0.05
DSS 14 70-m -2353621.251 -4641341.542 +3677052.370 0.03 0.03
DSS 15 34-m HEF -2353538.790 -4641649.507 +3676670.043 0.03 0.03
DSS 16 26-m X-Y -2354763.158 -4646787.462 +3669387.069 0.05 0.10
DSS 23 11-m Tilt/Az/El -2354757.567 -4646934.675 +3669207.824 0.05 0.10
DSS 24 34-m BWG -2354906.495 -4646840.128 +3669242.317 0.05 0.10
DSS 25 34-m BWG -2355022.066 -4646953.636 +3669040.895 0.05 0.10
DSS 26 34-m BWG -2354890.967 -4647166.925 +3668872.212 0.05 0.10
DSS 27 34-m HSB -2349915.260 -4656756.484 +3660096.529 0.05 0.10
DSS 28 Not in service -2350101.849 -4656673.447 +3660103.577 0.05 0.10
DSS 33 11-m Tilt/Az/El -4461083.514 +2682281.745 -3674570.392 0.03 0.10
DSS 34 34-m BWG -4461146.756 +2682439.293 -3674393.542 0.05 0.10
DSS 43 70-m -4460894.585 +2682361.554 -3674748.580 0.03 0.03
DSS 45 34-m HEF -4460935.250 +2682765.710 -3674381.402 0.03 0.03
DSS 46 26-m X-Y -4460828.619 +2682129.556 -3674975.508 0.04 0.04
DSS 53 11-m Tilt/Az/El +4849330.129 -0360338.092 +4114758.766 0.05 0.10
DSS 54 34-m BWG +4849434.555 -0360724.108 +4114618.643 0.05 0.10
DSS 63 70-m +4849092.647 -0360180.569 +4115109.113 0.03 0.03
DSS 65 34-m HEF +4849336.730 -0360488.859 +4114748.775 0.03 0.03
DSS 66 26-m X-Y +4849148.543 -0360474.842 +4114995.021 0.05 0.10
Notes: 1. All antennas are AZ-EL type unless otherwise specified. 2.
Horizontal (h) and vertical (v) uncertainties are 1-sigma.
Complex x(m/yr) y(m/yr) z(m/yr) e(m/yr) n(m/yr) v(m/yr)
Goldstone (Stations -0.0191 0.0061 -0.0047 -0.0198 -0.0057 -0.0001
1x & 2x)
Canberra (Stations -0.0354 -0.0017 0.0412 0.0197 0.0506 0.0001
3x & 4x)
Madrid (Stations 5x -0.0141 0.0222 0.0201 0.0211 0.0255 0.0011
& 6x)
lambda = arctan(y/x) (5)
phi = arctan((z(1-f)+e^2*a*sin^3(mu))/((1-f)(p-e^2*a*cos^3(mu)))) (6)
h = p*cos(phi) + z*sin-a(1-e^2*sin^2(phi))^(1/2) (7)
where:
e^2 = 2f-f^2
p = (x^2+y^2)^(1/2)
r = (p^2+z^2)^(1/2)
mu = arctan(z/p[(1-f)+e^2*a/r]
Table 5 provides geodetic coordinates derived by the preceding
approach using an ellipsoid with a semi-major axis (a) of 6378136.3 m and a
flattening (f) of 298.257.
Table 4. Geocentric Coordinates for DSN Stations
Antenna Geocentric Coordinates
Name Description Spin Radius (m) Latitude (deg) Longitude (deg) Geocentric
Radius (m)
DSS 13 34-m R & D 5215524.535 35.0660185 243.2055430 6372125.125
DSS 14 70-m 5203996.955 35.2443527 243.1104638 6371993.286
DSS 15 34-m HEF 5204234.332 35.2403133 243.1128069 6371966.540
DSS 16 26-m X-Y 5209370.715 35.1601777 243.1263523 6371965.530
DSS 23 11-m Tilt/Az/El 5209499.503 35.1581932 243.1271390 6371967.603
DSS 24 34-m BWG 5209482.486 35.1585349 243.1252079 6371973.553
DSS 25 34-m BWG 5209635.978 35.1562594 243.1246384 6371983.060
DSS 26 34-m BWG 5209766.971 35.1543411 243.1269849 6371993.032
DSS 27 34-m HSB 5216079.244 35.0571456 243.2233516 6372110.269
DSS 28 Not in service 5216089.176 35.0571462 243.2211109 6372122.448
DSS 33 11-m Tilt/Az/El 5205372.367 -35.2189880 148.9830895 6371684.945
DSS 34 34-m BWG 5205507.750 -35.2169868 148.9819620 6371693.561
DSS 43 70-m 5205251.579 -35.2209234 148.9812650 6371689.033
DSS 45 34-m HEF 5205494.708 -35.2169652 148.9776833 6371675.906
DSS 46 26-m X-Y 5205075.496 -35.2235036 148.9830794 6371676.067
DSS 53 11-m Tilt/Az/El 4862699.481 40.2375043 355.7503453 6370014.595
DSS 54 34-m BWG 4862832.239 40.2357708 355.7459008 6370025.429
DSS 63 70-m 4862450.981 40.2413537 355.7519890 6370051.221
DSS 65 34-m HEF 4862717.238 40.2373325 355.7485795 6370021.697
DSS 66 26-m X-Y 4862528.530 40.2401197 355.7485798 6370036.713
Notes: 1. All antennas are AZ-EL type unless otherwise specified.
Table 5. Geodetic Coordinates for DSN Stations
Antenna latitude (phi) longitude (lambda) height(h)
Name Description deg min sec deg min sec (m)
DSS 13 34-m R & D 35 14 49.79342 243 12 19.95493 1071.178
DSS 14 70-m 35 25 33.24518 243 6 37.66967 1002.114
DSS 15 34-m HEF 35 25 18.67390 243 6 46.10495 0973.945
DSS 16 26-m X-Y 35 20 29.54391 243 7 34.86823 0944.711
DSS 23 11-m Tilt/Az/El 35 20 22.38335 243 7 37.70043 0946.086
DSS 24 34-m BWG 35 20 23.61555 243 7 30.74842 0952.156
DSS 25 34-m BWG 35 20 15.40450 243 7 28.69836 0960.862
DSS 26 34-m BWG 35 20 08.48213 243 7 37.14557 0970.159
DSS 27 34-m HSB 35 14 17.78052 243 13 24.06569 1053.203
DSS 28 Not in service 35 14 17.78136 243 13 15.99911 1065.382
DSS 33 11-m Tilt/Az/El -35 24 01.76138 148 58 59.12204 0684.839
DSS 34 34-m BWG -35 23 54.53995 148 58 55.06320 0692.750
DSS 43 70-m -35 24 8.74388 148 58 52.55394 0689.608
DSS 45 34-m HEF -35 23 54.46400 148 58 39.65992 0675.086
DSS 46 26-m X-Y -35 24 18.05462 148 58 59.08571 0677.551
DSS 53 11-m Tilt/Az/El 40 25 38.48036 355 45 1.24307 0827.501
DSS 54 34-m BWG 40 25 32.23201 355 44 45.24283 0837.696
DSS 63 70-m 40 25 52.34908 355 45 7.16030 0865.544
DSS 65 34-m HEF 40 25 37.86055 355 44 54.88622 0834.539
DSS 66 26-m X-Y 40 25 47.90367 355 44 54.88739 0850.582
Notes: 1. All antennas are AZ-EL type unless otherwise
specified.
2.2 Coverage and Mutual Visibility
The coverage and mutual visibility provided for spacecraft tracking
depends on the altitude of the spacecraft, the type or types of antennas being
used, the blockage of the antenna beam by the landmask and structures in the
immediate vicinity of the antennas, and whether simultaneous uplink coverage
is required. Receive limits are governed by the mechanical capabilities of
the antennas and the terrain mask. Transmitter limits, on the other hand, are
based on radiation hazard considerations to on-site personnel and the general
public and are set above the terrain mask and the antenna mechanical limits.
2.2.1 Use of Transmitters Below Designated Elevation Limits
Requests for coordination to relinquish the transmitter radiation
restrictions will be considered for spacecraft emergency conditions or for
critical mission support requirements (conditions where low elevation or high-
power transmitter radiation is critical to mission objectives). In either
event, the uplink radiation power should be selected as the minimum needed for
reliable spacecraft support.
2.2.1.1 Spacecraft Emergencies
The need for violation of transmitter radiation restrictions to
support a spacecraft emergency will be determined by the DSN. The restrictions
will be released after assuring that appropriate local authorities have been
notified and precautions have been taken to ensure the safety of on-site
personnel.
2.2.1.2 Critical Mission Support
If critical mission activities require the transmitter radiation
restrictions to be violated, the project is responsible for notifying the DSN
through their normal point of contact three months before the activity is
scheduled. The request must include enough information to enable the DSN to
support it before the appropriate authorities. Requests made less than three
months in advance will be supported on a best-efforts basis and will have a
lower probability of receiving permission to transmit. Requests will be
accepted or denied a minimum of two weeks before the planned activity.
2.2.2 Mechanical Limits on Surveillance Visibility
All DSN antennas have areas of non-coverage caused by mechanical
limits of the antennas. The first area is the mechanical elevation limit, which
is approximately six degrees for antennas using an azimuth-elevation mount and
somewhat lower for antennas with X-Y mounts. A second area of non-coverage is
the area off the end or ends of the antenna's primary axis referred to as the
keyhole.
2.2.2.1 Azimuth-Elevation Antennas
The keyhole of the DSN azimuth-elevation antennas is directly
overhead and results from the fact that the antennas can only be moved over an
arc of approximately 85 degrees in elevation. In order to track a spacecraft
which is passing directly overhead, it is necessary to rotate the antenna 180
degrees in azimuth when the spacecraft is at zenith in order to continue the
track. Thus, the size of the keyhole depends on how fast the antenna can be
slewed in azimuth. Specifications on antenna motion are contained in module
302, Antenna Positioning. The location of the DSN antennas is such that
overhead tracks are not required for spacecraft on normal planetary missions.
The DSN azimuth-elevation antennas have an additional restriction on
antenna motion caused by the routing path of cables and hoses between the fixed
and rotating portions of the antenna. This azimuth cable wrap has no effect on
surveillance visibility but does place a restriction on the time between tracks
due to the requirement to unwind the cables. Table 6 provides the approximate
cable wrap limits for the DSN azimuth-elevation antennas.
2.2.2.2 X-Y Antennas
The DSN 26-m X-Y antennas (DSS 16, 46, and 66) have two keyholes
caused by requirements for mechanical clearance in the antenna structure. The
keyholes are located directly to the east and west of the 26-m antennas.
2.2.2.3 Tilt-Azimuth-Elevation Antennas
The DSN 11-m antennas (DSS 23, 33, and 53) have a keyhole above each
antenna, which is offset from zenith by 7-degrees. The location of this keyhole
is set before each pass to a position that will provide clearance between the
keyhole and the scheduled track.
2.2.3 Coverage Charts
The following figures provide examples of coverage for various
combinations of stations, spacecraft altitudes, and type of support. These
figures were plotted by a program written as a collection of Microsoft Excel
97/98 macros. This program is available for download
(1.7 Mbytes) from the 810-005 web site
(http://eis.jpl.nasa.gov/deepspace/dsndocs/810-005/).
2.2.3.1 70-m Subnet Receive Coverage of Planetary Spacecraft
Figure 2 illustrates the receive coverage of planetary spacecraft by
the DSN 70-m antenna subnet. The small ovals at each antenna location on the
figure represent the 70-m antenna keyholes above each station and are
approximately to scale.
Table 6. Approximate Cable Wrap Limits for Azimuth-Elevation Antennas
Antenna Azimuth Position (Degrees)
Name(s) Description Center of Wrap CW Limit CCW Limit
DSS 14, 63 70-m 45 310 140
DSS 43 70-m 135 40 230
DSS 15, 65 34-m HEF 135 360 270
DSS 45 34-m HEF 45 270 180
DSS 24, 25, 26, 54, 65 34-m BWG 135 360 270
DSS 34 34-m BWG 45 270 180
DSS 27 34-m HSB 135 360 270
DSS 23, 33, 53 11-m 0 380 (-)380
2.2.3.2 70-m Subnet Transmit Coverage of Planetary Spacecraft
Figure 3 illustrates the transmit coverage of planetary spacecraft by
the DSN 70-m antenna subnet using a 10.4-degree transmit elevation limit at
DSS 14 and a 10.2-degree transmit elevation limit at DSS 43 and DSS 63. The
small ovals at the antenna locations on the figure represent the 70-m antenna
keyholes. The reduced coverage to the west of DSS 63 is caused by the need to
have a 20.2-degree elevation limit to protect the high ground to the northwest
of the station.
2.2.3.3 34-m HEF Subnet Receive Coverage of Planetary Spacecraft
Figure 4 illustrates the receive coverage of planetary spacecraft by
the DSN 34-m HEF antenna subnet. The keyhole above each 34-m HEF antenna is
very small and is somewhat exaggerated for clarity on the maps. This chart is
very similar to Figure 2 but is included to show that the location of DSS 65
shifts the apparent position of the high ground to the north and west of where
it is observed from DSS 63.
2.2.3.4 34-m HEF Subnet Transmit Coverage of Planetary Spacecraft
Figure 5 illustrates the transmit coverage of planetary spacecraft by
the DSN 34-m HEF antenna subnet using a 10.6-degree transmit elevation limit at
DSS 15, a 10.5-degree transmit limit at DSS 45, and a 10.3-degree limit at DSS
65. As is the case in Figure 4, the size of the circles used to indicate the
keyholes on the map are larger than the actual size of the 34-m HEF antenna
keyholes. Protection of the high ground at DSS 65 is provided by disabling the
transmitter between 327.4 and 358.6 degrees azimuth.
2.2.3.5 34-m BWG Antennas Receive Coverage of Planetary Spacecraft
Figure 6 illustrates the receive coverage of planetary spacecraft by
the DSN 34-m BWG antennas. As is the case with the other 34-m antennas, the
size of the circles on the map is larger than the actual size of the antenna
keyholes. This chart is very similar to Figures 2 and 4 but is included to show
that the location of DSS 54 shifts the apparent position of the high ground even
further to the north and west of where it is observed from DSS 63 than is the
case with the DSS 65 34-m HEF antenna.
2.2.3.6 34-m BWG Antennas Transmit Coverage of Planetary Spacecraft
Figure 6 illustrates the transmit coverage of planetary spacecraft by
the DSN 34-m BWG antennas. As is the case with the other 34-m antennas, the
size of the circles on the map is larger than the actual size of the antenna
keyholes. Protection of the high ground at DSS 54 is provided by disabling the
transmitter between 267 and 3 degrees azimuth.
2.2.3.7 26-m Subnet Receive Coverage of Earth Orbiter Spacecraft
Figure 8 illustrates the receive coverage of Earth-orbiter spacecraft
at altitudes of 200 km, 1000 km, and 5000 km by the DSN 26-m antenna subnet.
This chart can also be used when the 34-m HSB antenna, DSS 27, is substituted
for the Goldstone 26-m antenna. DSS 27 is collocated with an inactive antenna,
DSS 28, approximately 14.5 km southeast of DSS 16. The inactive antenna blocks
reception to the west in the same place and approximately to the same extent as
the west keyhole of DSS 16.
2.2.3.8 26-m Subnet Transmit Coverage of Earth Orbiter Spacecraft
Figure 9 illustrates the transmit coverage of Earth-orbiter
spacecraft at altitudes of 200 km, 1000 km, and 5000 km by the DSN 26-m
antenna subnet. This chart is similar to Figure 8. However, the limits
placed on transmitter operation in order to clear terrain and structures are
clearly visible.
2.2.3.9 34-m BWG Antennas Receive Coverage of Earth Orbiter Spacecraft
Figure 10 illustrates the receive coverage of Earth-orbiter spacecraft
by the DSN 34-m BWG antennas at altitudes of 500 km, 5000 km, and geosynchronous
altitude (35789 km). As is the case with the other 34-m antennas, the size of
the circles on the map is larger than the actual size of the antenna keyholes
2.2.3.10 34-m BWG Antennas Receive Coverage of Earth Orbiter Spacecraft
Figure 11 illustrates the transmit coverage of planetary spacecraft
by the DSN 34-m BWG antennas. As is the case with the other 34-m antennas, the
size of the circles on the map is larger than the actual size of the antenna
keyholes. Protection of the high ground at DSS 54 is provided by disabling the
transmitter between 267 and 3 degrees azimuth.
2.2.3.11 11-m Subnet Receive Coverage
Figure 12 illustrates the receive coverage of the 11-m Orbiting Very-
long Baseline Interferometry (OVLBI) subnet at 5000 km, geosynchronous altitude
(35789 km), and planetary range. The irregular coverage outlines are the result
of high ground to the east of DSS 33 and northwest of DSS 54 plus blockage due
to other antennas and structures at each complex.
2.2.4 Horizon Masks and Antenna Limits
Figures 13 through 30 show the horizon mask and transmitter limits for
all DSN stations. The transmitter limits are identified as the L/P (low power)
transmitter mask (or the H/P (high power) transmitter mask depending on the type
of transmitter that is available. Only the 70-m stations have both L/P and H/P
transmitters, and DSS 43 is the only station that uses different H/P and L/P
transmitter limits. At DSS 43, the H/P transmitter limit is set at 10.4 degrees
whereas the L/P transmitter limit is set at 10.2 degrees. DSS 14 uses a 10.4-
degree limit for both transmitters, and DSS 63 uses a 10.2-degree limit except
to the northwest of the station where it is set to 20.2 degrees. These masks
and limits are the ones used to establish the coverage depicted in Figures 2
through 11. Each chart shows antenna coordinates in two coordinate systems.
For all antennas except those with X-Y mounts, the coordinate systems are
azimuth-elevation and hour angle-declination. The antennas with X-Y mounts show
azimuth-elevation and X-Y coordinates.
Charts showing hour angle-declination coordinates can be used to
provide an elevation profile (for estimating antenna gain and noise
temperature) for spacecraft at planetary distances where the declination
remains constant for an entire tracking pass. The hour angle curves on these
charts have been spaced at increments of 15 degrees so that pass length may
conveniently be estimated. These figures were plotted by a program written as
a collection of Microsoft Excel 97/98 macros. This program is available for
download (1.1 Mbytes) from the 810-5 web site
(http://eis.jpl.nasa.gov/deepspace/dsndocs/810-005/). This file also contains
the land mask data, which can be used to accurately calculate spacecraft rise
and set times.
3 Proposed Capabilities
3.1 70-m X-band Uplink Implementation
An X-band transmit capability is being added to the 70-m antenna
subnet. The X-band transmit coverage will be the same as is presently
depicted in Figure 3.
3.2 34-m BWG Ka-band Implementation
A Ka-band receive capability is being added to all 34-m BWG
antennas. The Ka-band receive coverage will be the same as is presently
depicted in Figure 6.
Figure 2. DSN 70-m Subnet Receive Coverage, Planetary Spacecraft
(Figure omitted in text-only document)
Figure 3. DSN 70-m Subnet Transmit Coverage, Planetary Spacecraft
(Figure omitted in text-only document)
Figure 4. DSN 34-m HEF Subnet Receive Coverage, Planetary Spacecraft
(Figure omitted in text-only document)
Figure 5. DSN 34-m HEF Subnet Transmit Coverage, Planetary Spacecraft
(Figure omitted in text-only document)
Figure 6. DSN 34-m BWG Antennas Receive Coverage, Planetary Spacecraft
(Figure omitted in text-only document)
Figure 7. DSN 34-m BWG Antennas Transmit Coverage, Planetary Spacecraft
(Figure omitted in text-only document)
Figure 8. DSN 26-m Subnet Receive Coverage, Earth Orbiter Spacecraft
(Figure omitted in text-only document)
Figure 9. DSN 26-m Subnet Transmit Coverage, Earth Orbiter Spacecraft
(Figure omitted in text-only document)
Figure 10. DSN 34-m BWG Antennas Receive Coverage, Earth Orbiter Spacecraft
(Figure omitted in text-only document)
Figure 11. DSN 34-m BWG Antennas Transmit Coverage, Earth-Orbiter Spacecraft
(Figure omitted in text-only document)
Figure 12. DSN 11-m Subnet Earth-Orbiter and Planetary Receive Coverage
(Figure omitted in text-only document)
Figure 13. DSS 14 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 14. DSS 15 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 15. DSS 16 X-Y Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 16. DSS 23 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 17. DSS 24 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 18. DSS 25 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 19. DSS 26 Hour Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 20. DSS 27 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 21. DSS 33 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 22. DSS 34 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 23. DSS 43 Hour Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 24. DSS 45 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 25. DSS 46 X-Y Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 26. DSS 53 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 27. DSS 54 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 28. DSS 63 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 29. DSS 65 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
Figure 30. DSS 66 X-Y Profiles and Horizon Mask
(Figure omitted in text-only document)
Appendix A
References
1 C. Boucher, Z. Altamimi, and L. Duhem, Results and analysis of the ITRF93,
IERS Technical Note 18, Observatoire de Paris, October 1994
2 B. R. Bowring, "The accuracy of geodetic latitude and height equations,"
Survey Review, 28, pp. 202-206, 1985.
810-005, Rev. E
DSMS Telecommunications Link
Design Handbook
303
Media Calibration
Effective November 30, 2000
Document Owner: Approved by:
----------------------- -----------------------
P.H. Richter Date A. Kwok Date
Tracking and Navigation Service
Systems Development Engineer
Released by:
[Signature on file in TMOD Library]
------------------------
DSMS Document Release Date
Change Log
Rev Issue Date Affected Paragraphs Change Summary
Initial 1/15/2001 All All
Note to Readers
There are two sets of document histories in the 810-005 document, and these
histories are reflected in the header at the top of the page. First, the entire document is
periodically released as a revision when major changes affect a majority of the modules. For
example, this module is part of 810-005, Revision E. Second, the individual modules also
change, starting as an initial issue that has no revision letter. When a module is changed, a
change letter is appended to the module number on the second line of the header and a summary
of the changes is entered in the module's change log.
This module supersedes module MED-10 in 810-005, Rev. D.
Contents
Paragraph Page
1 Introduction.......................................................................................... 4
1.1 Purpose ............................................................................................ 4
1.2 Scope............................................................................................... 4
2 General Information .................................................................................. 4
2.1 Global Positioning System Data ..................................................................... 4
2.1.1 GPS Signal Structure.............................................................................. 5
2.1.2 GPS Receiver/Processor Assembly (GRA)............................................................. 6
2.1.3 Relation of Phase and Group Delay to Atmospheric Properties....................................... 7
2.2 Ground Weather Data ............................................................................... 14
Tables
Table Page
1. GPS Metric Data, Code Mode............................................................................ 7
2. GPS Metric Data, Non-Code Mode ....................................................................... 9
3. GPS Ephemeris Data................................................................................... 10
4. GPS Almanac Data..................................................................................... 12
5 Weather Data Transmitted from the SCA................................................................. 14
1 Introduction
1.1 Purpose
This module describes the capabilities of the equipment used by the
Deep Space Network (DSN) to obtain data from which correction factors can be
determined for media effects that limit navigational accuracy. The data are
forwarded from each Deep Space Communications Complex (DSCC) to the Net
work Operations Control Center (NOCC) where they are processed and archived.
1.2 Scope
The functional performance and data characteristics of the Deep
Space Station (DSS) Media Calibration Subsystem (DMD) are described. The DMD
is responsible for obtaining Global Positioning System (GPS) and ground
weather data for the NOCC Tracking Subsystem (NTK) and Navigation Subsystem
(NAV).
2 General Information
The DMD provides two types of data:
-GPS data consisting of L-band carrier phase and group delay of GPS
satellite signals, in addition to ephemeris and almanac data for the GPS
satellites.
-Weather data, consisting of temperature, barometric pressure, relative
humidity, precipitation rate, total precipitation, wind speed, and wind
direction.
2.1 Global Positioning System Data
The Global Positioning System GPS Operational Constellation consists
of at least 24 satellites that orbit the earth with a 12 sidereal-hour period.
There are often more than 24 as new satellites are launched to replace the older
ones. The orbit is such that the satellites repeat the same track and
configuration over any point approximately each 24 hours (4 minutes earlier each
day). There are six orbital planes (with nominally four satellites in each),
equally spaced (60 degrees apart), and inclined at about fifty-five degrees with
respect to the equatorial plane. This constellation provides the user with
between five and eight satellites visible from any point on the Earth. A minimum
of four satellite signals must be received to estimate the four unknowns of
position in three dimensions and time.
The DSCC GPS Receiver/Processor Assembly (GRA), which is part of the
DMD, makes use of the GPS data to provide carrier phase and group delay for the
GPS signals.
These data may then be used to characterize the Earth's ionosphere and
troposphere along the line of sight from a given satellite to the DSCC.
2.1.1 GPS Signal Structure
The GPS satellite signals are complex in structure, with each L-
band frequency being binary biphase-modulated with two pseudo-random noise
codes, the Coarse Acquisition (C/A) and Precision (P) codes, and a navigation
message.
The complete signal broadcast by a satellite may be represented as:
s(t) = [A_C * C(t)D(t)sin(2(pi)f_1*t) + A_P * P(t)D(t)cos(2(pi)f_1*t)] (1)
+ [A_p * P(t)D(t)cos(2(pi)f_2*t)]
where the first square bracket is the L1 signal at frequency f1, and the second
square bracket is the L2 signal at frequency f2. The terms appearing above have the
following definitions:
A_c and A_p = the constant amplitudes of the Coarse Acquisition (C/A) and Precision (P) codes
C(t) = the C/A-code modulation (= +/-1)
P(t) = the P-code modulation (= +/-1)
D(t) = the navigation message modulation (= +/-1)
f_1 = 154 f_0 = 1575.42 MHz
f_2 = 120 f_0 = 1227.60 MHz.
The C(t), P(t), and D(t) modulations are all synchronized to the
fundamental clock frequency, f_0, such that they have the following frequencies:
f_0 = 10.23 MHz (Note 1)
C(t)= f_0/10 = 1.023 Mbps
P(t)= f_0 = 10.23 Mbps
D(t)= f_0/204600 = 50 bps.
Note (1): To partially compensate for general and special relativistic effects
on the satellite clock (gravitational red shift and time dilation),
the actual value of f_0 is 10.23 MHz - 4.55 mHz.
The complete C/A code contains 1023 cycles (or "chips"), has a total
period of 1.0 ms, and is different for each satellite.
The P-code is more complicated and consists of two code segments (X1
and X2), which differ in length by 37 chips. These are added modulo 2 and timed
in such a way that exactly 403,200 X1 code segments correspond to exactly one
week, the period of the P-code. (The P-code actually has a total period of 37
weeks, with each satellite using only a single one-week segment of the total.)
The duration of the X1 code segment is thus 1.5 seconds and contains exactly
15,345,000 chips at 10.23 Mbps. As is the case with the C/A code, the P-code is
different for each satellite.
The navigation message also has a complex structure, with a total
period of 12.5 minutes (one master frame) and is divided into frames,
subframes, words, and bits. The first three subframes (lasting 6 seconds each)
repeat every 30 seconds, while the last two subframes are different in each of
25 consecutive frames (pages), after which the entire message repeats.
2.1.2 GPS Receiver/Processor Assembly (GRA)
The GRA provides the following functional capabilities:
1) Automatically acquire and track the L1 and L2 GPS signals for
specified satellites, usually all of those transiting
2) Extract and store GPS almanac and ephemeris data from the
navigation message
3) Measure the differential P-code group delay between the L1 and
L2 GPS signals
4) Measure the differential carrier phase between the L1 and L2 GPS
signals.
The almanac data, contained in subframe 5 of the GPS navigation
message, consist of approximate ephemeris data for all satellites and are used
by the GRA for signal acquisition.
The ephemeris data for a specified satellite (subframes 2 and 3)
provide a complete description of the orbit. When the data are combined with
measured signal delays, the local position and atmospheric path that the signal
has traversed can be determined.
Since the Department of Defense, which controls the GPS signal
content, may elect at any time to encrypt the P-code (resulting in what is
termed an anti-spoofing (A/S) mode of operation in which the encrypted, or Y-
code, is unavailable to civilian users of the system) the GRA operates in two
distinct modes to determine the differential group and phase delays of the
satellite signals.
In the normal, coded mode, the known P-code is used to determine the
carrier phase and group delay of each signal (L1 and L2) separately. The
computed differences may then be used to characterize the propagation medium
over the path of the signals. This provides the most precise determination due
to the length of the P-code.
In the codeless mode, advantage is taken of the fact that the same
unknown Y-code is transmitted on both the L1 and L2 channels with an unknown
delay. The product of the two signals is formed and the differential group and
phase delays are determined by cross-correlation. This method results in a
somewhat reduced accuracy.
The GRA simultaneously receives and processes the signals from up to
eight satellites selected to provide the longest unbroken tracks at any given
time. In addition to the data described above, the system provides various
status and health data on the signals being processed. Tables 1 through 4 list
the GPS parameters measured, their ranges and accuracy, and the sample
intervals provided.
2.1.3 Relation of Phase and Group Delay to Atmospheric Properties
The Earth's atmosphere may conveniently be divided into three regions
according to the effects produced on the propagation of electromagnetic
radiation:
(1) troposphere, stratosphere, and lower part of mesophere - region
between the Earth's surface and about 60 km altitude consisting of neutral
(unionized) gases
(2) ionosphere - region from about 60 km to between ~500 and 2000 km,
depending on the extent of extraterrestrial ionizing radiation, consisting of
partially ionized gases
. (3) plasmasphere - ionized region extending from ~2000 km to about four
Earth radii (26,000 km), where it blends into the solar wind of the Earth's
magnetosphere
At the frequencies in which the DSN operates, tropospheric
dispersion may be neglected and the refractivity represented by a dry and a
wet component whose approximate total zenith phase and group delays are:
delta t_D ~ 7.6 ns,
delta t_W ~ 0.3 ns - 1.4 ns.
The first varies linearly with pressure at the Earth's surface; the
second increases as the tropospheric moisture content increases.
Since tropospheric dispersion is negligible at L-band, these delays
cancel when differential delays are computed or measured between f_1 and f_2.
In the ionized portion of the Earth's atmosphere, the medium displays
anomalous dispersion at microwave frequencies. This causes the phase velocity to
exceed, and the group velocity to be less than, the speed of light in a vacuum,
c. Specifically, to a good approximation at L-band:
v/c = 1 + x/2 (2)
v_g/c = 1 - x/2 (3)
Table 1. GPS Metric Data, Code Mode
Parameter Units (1) Approximate Decimal Range
Delay Calibration 2^-7 ns +/-255 ns
Output Interval sec 1-300 s
L1-C/A Doppler Phase 2^-16 cycles +/-2.1 x 10^9 cycles
L1-C/A Doppler Phase Noise 2^-16 cycles 0-1 cycle
L1-P Doppler Phase 2^-16 cycles +/-2.1 x 10^9 cycles
L1-P Doppler Phase Noise 2^-16 cycles 0-1 cycle
L2-P Doppler Phase 2^-16 cycles +/-2.1 x 10^9 cycles
L2-P Doppler Phase Noise 2^-16 cycles 0-1 cycle
L1-C/A Group Delay 2^-11 ns +/-0.27 sec
L1-C/A Group Delay Noise 2^-11 ns 0-32 ns
L1-P Group Delay 2^-11 ns +/-0.27 sec
L1-P Group Delay Noise 2^-11 ns 0-32 ns
L2-P Group Delay 2^-11 ns +/-0.27 sec
L2-P Group Delay Noise 2^-11 ns 0-32 ns
C/A SNR (1 sec) 2^-4 volt/volt 0-4096
P1 SNR (1 sec) 2^-4 volt/volt 0-4096
P2 SNR (1 sec) 2^-4 volt/volt 0-4096
Receiver Clock Error 2^-32 sec +/-0.5 sec
L1-C/A Residual Phase 2^-10 cycles 0-0.25 cycle
Note (1): Least significant bit transmitted by the GRA. Table 2. GPS Metric
Data, Non-Code Mode
Parameter Units (1) Approximate Decimal Range
Delay Calibration 2^-7 ns +/-255 ns
Output Interval sec 1-300 sec
L1-C/A Doppler Phase 2^-16 cycles +/-2.1 x 10^9 cycles
L1-C/A Doppler Phase Noise 2^-16 cycles 0-1 cycle
L1-L2 Doppler Phase 2^-16 cycles +/-2.1 x 10^9 cycles
L1-L2 Doppler Phase Noise 2^-16 cycles 0-1 cycle
L1-C/A Group Delay 2^-11 ns +/-2.1 x 10^9 cycles
L1-C/A Group Delay Noise 2^-11 ns 0-32 ns
P2-P1 Group Delay 2^-9 ns +/-1.1 s
P2-P1 Group Delay Noise 2^-9 ns 0-128 ns
C/A SNR (1 s) 2^-4 volt/volt 0-4096
P2-P1 SNR (1 s) 2^-6 volt/volt 0-1024
Receiver Clock Error 2^-32 s +/-0.5 s
L1-C/A Residual Phase 2^-10 cycles 0-0.25 cycle
Note (1): Least significant bit transmitted by the GRA. Table 3. GPS Ephemeris
Data
Parameter Units (1) Approximate Decimal Range
Sample Year (Modulo 100) Year 0-99 yrs
Sample Day-of-Year Days 0-366 days
Sample Hours Hours 0-24 hrs
Sample Minutes Minutes 0-60 minutes
Sample Seconds seconds 0-60 s
GPS Week Number N/A
Satellite Number N/A
L2 Code Type/L2 Code On N/A
User Range Accuracy N/A
Issue of Data (Clock) N/A
Clock Data Reference Time (toc) 24 s 0-6.0 x 10^5 s
Time Correction Coefficient (af2) 2^-55 s/s2 +/-3.6 x 10^-15 s/s2
Time Correction Coefficient (af1) 2^-43s/s +/-3.7 x 10^-9 s/s
Time Correction Coefficient (af0) 2^-31s +/-3.9 ms
Issue of Data (Ephemeris) N/A
Amplitude of Sine Harmonic 2^-5m +/-1.0 km
Correction to the Orbit Radius (Crs)
Mean Motion Difference From Computed 2^-43 semicir/s +/-1.2 x 10^-5 mrad/s
Values (Delta N)
Mean Anomaly at Reference Time (Mo) 2^-31 semicir +/-180 deg
Amplitude of Cosine Harmonic 2^-29 radians +/-6.1 x 10^-2 mrad
Correction to the Argument of
Latitude (Cuc)
Eccentricity (e) 2^-33 0-0.03
Amplitude of Sine Harmonic 2^-29 radians +/-6.1 x 10^-2 mrad
Correction to the Argument of
Latitude (Cus)
Square Root of Semi-Major Axis 2^-19 m^(1/2) 0-8200 m1/2
(A1/2)
Ephemeris Reference Time (t0E) 24 s 0-6.0 x 105 s
Note (1): Least significant bit transmitted by the GRA. 10
Table 3. GPS Ephemeris Data (Continued)
Parameter Units (1) Approximate Decimal Range
Amplitude of Cosine Harmonic Correction 2^-29 radians +/-6.1 x 10^-2 mrad
to Inclination (Cic)
Right Ascension at Reference Time 2^-31 semicir +/-180 deg
(Omega0)
Amplitude of Sine Harmonic Correction 2^-29 radians +/-6.1 x 10-2 mrad
to Inclination (Cis)
Inclination at Reference Time (i0) 2^-31 semicir +/-180 deg
Amplitude of Cosine Harmonic Correction 2^-5 m +/-1.0 km
to the Orbit Radius (Crc)
Argument of Perigee (Omega) 2^-31 semicir +/-180 deg
Right Ascension Rate (Omega DOT) 2^-43 semicir/s +/-3.0 x 10^-3 mrad/s
Issue of Data (Ephemeris) N/A
Inclination Angle Rate (IDOT) 2^-43 semicir/s +/-1.2 x 10^-5 mrad/s
Note (1): Least significant bit transmitted by the GRA. Table 4. GPS Almanac
Data
Parameter Units (1) Approximate Decimal Range
Sample Year (Modulo 100) Year 0-99 yr.
Sample Day-of-Year Days 0-366 days
Sample Hours Hours 0-24 hrs
Sample Minutes Minutes 0-60 minutes
Sample Seconds s 0-60 s
GPS Week Number N/A
Satellite Number N/A
Data and Space Vehicle ID N/A
Eccentricity (e) 2^-21 0-0.03
Reference Time (tOA) 2^+12 s 0-6.0 x 10^5 s
Delta Inclination (di) 2^-19 semicir +/-11 deg
Right Ascension Rate (Omega DOT) 2^-38 semicir/sec +/-3.7 x 10^-4 mrad/s
Square Root of Semi-Major Axis 2^-11 m^(1/2) 0-8200 m1/2
(A1/2)
Right Ascension at Reference Time 2^-23 semicir +/-180 deg
(Omega0)
Argument of Perigee (Omega) 2^-23 semicir +/-180 deg
Mean Anomaly (M0) 2^-23 semicir +/-180 deg
Correction Term (af0) 2^-20 s +/-0.03 deg
Correction Term (af1) 2^-38 s +/-1.2 x 10^-7 s/s
Note (1): Least significant bit transmitted by the GRA.
where:
v = phase velocity = omega/k
v_g = group velocity = d(omega)/dk
k = wave vector (lambda/2(pi))
x = (f_p/f)^2 << 1
f = frequency of interest
f_p = plasma frequency = (N*e^2/m(epsilon_0))^(1/2)/2(pi)
N = electron density (electrons/m^3)
e = electronic charge
m = electronic mass
epsilon_0 = permittivity of free space.
In terms of the above, the phase (delta t) and group (delta t_g) delays at
frequency f may be written:
delta t_g = -delta t = (1.345x10^-7/f^2) x TEC, s (4)
where TEC = integral(N dl) is the total electron content (TEC) along the propagation
path (electrons/m^2).
The corresponding differential delays are given by:
DELTA t_g = -DELTA t = 1.345x10^-7 (1/f_2^2 - 1/f_1^2) x TEC, s (5)
where DELTA t_g = delta t_g(f_2) - delta t_g(f_1).
Since the TEC along the satellite line of sight may vary between
~10^16 and 4x10^18 m^-2, the group and phase delays typically range between ~0.5 ns
and 90 ns, and the differential delays between ~0.35 ns and 35 ns, although
larger values are often observed during periods of high solar activity.
2.2 Ground Weather Data
The ground weather data are generated by instruments located near the
Signal Processing Centers (SPC) at each DSCC. In particular, the wind speed and
direction sensors are adjacent to the 34m HEF antennas.
All data are asampled once per second by the instruments, and the
resulting data stream is transmitted to the Subsystem Control and Monitor
Assembly (SCA) of the DMD. Here the data are packaged and transmitted to the NTK
and NAV at regular intervals and stored for up to five days for later recall.
Table 5 lists the weather parameters measured, their ranges and accuracy, and
the interval of transmission to the NTK, NAV, and DMC.
Table 5 Weather Data Transmitted from the SCA
Parameter Range Accuracy Transmission Interval
Default Range
Temperature -50 to +50deg C +/-0.1deg C 60 s 10 s to 1 hr
Barometric Pressure 600 to 1100 mbar 1.0 mb 60 s 10 s to 1 hr
Relative Humidity(1) 0 to 100% 2% 60 s 10 s to 1 hr
Dew Point -40 to 50deg C +/-0.5deg C 60 s 10 s to 1 hr
Temperature
Precipitation Rate 0 to 250 mm/hr 5% 60 s 10 s to 1 hr
Total Precipitation >0 mm 5% 60 s 10 s to 1 hr
Wind Speed(2) 0 to 100 km/hr +/-0.6 km/hr 60 s 10 s to 1 hr
Wind Direction(2) 0 to 360 deg +/-3.6 deg 60 s 10 s to 1 hr
See notes on following page.
(1) Relative humidity is calculated from the measured weather parameters
according to the formula:
RH =10^x percent, (6)
where:
x = 2 + 2300 (1/T - 1/T_d),
T = temperature in Kelvins
T_d = dew point temperature in Kelvins.
(2) Wind data are averaged over 10-s intervals by converting the polar velocity vector:
v_w =S_w * (e-hat)(theta) (7)
where:
S_w = wind speed
(e-hat)(theta) = wind direction unit vector
to rectangular form,
v_w = S_x * (i-hat)(theta) + S_y * (j-hat)(theta) (8)
and computing and , where
^2 = ^2 + ^2,
= arctan(/),
S_x = S_w * cos(theta),
810-005, Rev. E
DSMS Telecommunications Link
Design Handbook
901
Handbook Glossary
Effective November 30, 2000
Document Owner: Approved by:
----------------------- -----------------------
S.D. Slobin Date A.J. Freiley Date
Antenna System Engineer Antenna Product Domain Service
System Development Engineer
Released by:
[Signature on file in TMOD Library]
----------------------------------
TMOD Document Release Date
Change Log
Rev Issue Date Affected Paragraphs Change Summary
Initial 1/15/2001 All All
Note to Readers
There are two sets of document histories in the 810-005 document, and these
histories are reflected in the header at the top of the page. First, the entire document is
periodically released as a revision when major changes affect a majority of the modules. For
example, this module is part of 810-005, Revision E. Second, the individual modules also
change, starting as an initial issue that has no revision letter. When a module is changed, a
change letter is appended to the module number on the second line of the header and a summary
of the changes is entered in the module's change log.
This module supersedes Appendix A in 810-005, Rev. D.
Contents
Paragraph Page
1 Introduction.......................................................................................... 3
1.1 Purpose ............................................................................................ 3
1.2 Scope .............................................................................................. 3
1.3 Revisions .......................................................................................... 4
1.4 Definitions......................................................................................... 4
1.4.1 Terms ............................................................................................ 4
1.4.2 Abbreviations..................................................................................... 4
1.4.3 Acronyms.......................................................................................... 4
1.5 Controlling Documents .............................................................................. 4
2 Glossary of Abbreviations and Terms................................................................... 5
1 Introduction
1.1 Purpose
The purpose of this document is to present a useful glossary of commonly used terms, abbreviations, and
acronyms that are current and applicable to the Deep Space Network (DSN) and the Telecommunications and
Mission Operations Directorate (TMOD) of the Jet Propulsion Laboratory.
1.2 Scope
This scope of this document is limited to providing terms, abbreviations, and acronyms that are used
within Document 810-005 and especially those that may be different from usage in other organizations.
Terms, abbreviations, and acronyms are included in this document if they meet any of the following
criteria:
- used within the DSN or TMOD but with a meaning that may be unique to the DSN or TMOD,
- used within 810-005 in place of equivalent terms, abbreviations, and acronyms that may be used elsewhere, or
- commonly used in the field of telecommunications engineering but not necessarily known to all users of 810-005.
1.3 Revisions
This glossary will be periodically revised with changes, improvements, or additions. Usually, these revisions
will be coincident with the publication of new or revised 810-005 modules that contain new or revised
terminology.
1.4 Definitions
The following paragraphs define the types of items that appear in this glossary and give general rules for their
formation.
1.4.1 Terms
A term is any word or expression that has a precise meaning in a particular field, in this case,
telecommunications engineering.
1.4.2 Abbreviations
An abbreviation is a shortened or contracted form of a word or phrase. In a strict sense, the letters are
individually pronounced (for example, rpm or DSN) or the reader might visualize and pronounce the complete
form of the word (for example, "assembly" for "assy" or "telemetry" for "TLM").
1.4.3 Acronyms
An acronym is a pronounceable abbreviation formed by one of two methods:
(1) combining the first syllables of the key words (for example, Caltech or FORTRAN) or
(2) combining the first letter and other letters, as required, from the name or key words of an organization,
project, or piece of equipment (for example, AMMOS or LAN).
1.5 Controlling Documents
The terms, abbreviations, and acronyms contained in this document are intended to be consistant with those
defined in JPL internal publication, DSMS Requirements and Design -- DSMS Terms and Abbreviations; DSMS
Document 820-062 which serves as the controlling document for this module.
Abbreviations and Terms
Abbreviation or Term Definition
A
A-D analog-to-digital
A/S anti-spoofing mode of operation (Global Positioning System)
in which the encrypted, or Y-code, is unavailable to civilian users of the system
AFC automatic frequency control
AGC automatic gain control
alidade The rotating but non-tilting portion of the DSN azimuth-
elevation antennas.
AM amplitude modulation
AMP amplifier
AMMOS Advanced Multimission Operations System
ARC ambiguity resolving code
ASM attached synchronization marker
atm atmospheric
az azimuth
AZ-EL azimuth-elevation
B
B2MCD Block II Maximum Likelihood Convolutional Decoder
B3MCD Block III Maximum Likelihood Convolutional Decoder
B/W bandwidth
BER bit error rate
BET_L lock bit error tolerance
BET_S search bit error tolerance
Boltzmann constant -198.6 dBW/(Hz * K)
BPSK binary phase shift keying
BVR Block V Receiver (part of DTT Subsystem)
BWG Beam Waveguide (antenna or subnet)
C
c speed of light, 299,792.5 km/s
Category A missions within 2 million km of Earth
Category B missions at distances greater than 2 million km from Earth
C/A Coarse Acquisition (GPS code)
CCSDS Consultative Committee for Space Data Systems
CCW counter-clockwise
CD cumulative distribution
CDSCC Canberra (Australia) Deep Space Communications Complex
CONSCAN conical scanning
CPA Command Processor Assembly
cryo cryogenic
CSS Channel-Select Synthesizer
CV connection vector
CW clockwise
D
D/C downconverter
D/L downlink
dB decibel(s)
dBc decibel(s) with respect to carrier
dBi decibel(s) with respect to isotropic
dBm decibel(s) with respect to one milliwatt
DCC Downlink Channel Controller
DCPC DTT Controller Processing Cabinet
DDC Digital Downconverter
dec declination
deg degree(s)
DIG digitizer (assembly)
DLT digital linear tape
DMC DSS Monitor and Control
DMD DSS Media Calibration Subsystem
DN, dn down
DRVID differenced range versus integrated Doppler
DSCC Deep Space Communications Complex
DSN Deep Space Network
DSMS Deep Space Mission System
DSS Deep Space Station
DSS 14 70-m antenna at Goldstone DSCC
DSS 15 34-m HEF antenna at Goldstone DSCC
DSS 16 26-m antenna at Goldstone DSCC
DSS 23 11-m antenna at Goldstone DSCC
DSS 24 34-m BWG antenna at Goldstone DSCC
DSS 25 34-m BWG antenna at Goldstone DSCC
DSS 26 34-m BWG antenna at Goldstone DSCC
DSS 27 34-m HSB antenna at Goldstone DSCC
DSS 33 11-m antenna at Canberra DSCC
DSS 34 34-m BWG antenna at Canberra DSCC
DSS 43 34-m HEF antenna at Canberra DSCC
DSS 45 34-m HEF antenna at Canberra DSCC
DSS 46 26-m antenna at Canberra DSCC
DSS 63 34-m HEF antenna at Madrid DSCC
DSS 65 34-m HEF antenna at Madrid DSCC
DSS 66 26-m antenna at Madrid DSCC
DSS 53 11-m antenna at Madrid DSCC
DSS 54 34-m BWG antenna at Madrid DSCC
DTF Development and Test Facility
DTK DSS Tracking (Subsystem)
DTT Downlink Telemetry and Tracking (Subsystem)
E
EIRP effective isotropic radiated power
el, EL, elev elevation
EOP Earth Orientation Parameters (of the International Earth Rotation Service [IERS])
F
F/O fiber optic
FCD feedback concatenated decoding
FER frame error rate
FET field-effect transistor
FFT fast Fourier transform
FM frequency modulation
FOM figure of merit
FSK frequency-shift keyed
FTP file transfer protocol
FTS Frequency and Timing Subsystem
G
G/T (antenna) gain divided by (operating system) temperature
GCF Ground Communications Facility
GDSCC Goldstone (California) Deep Space Communications Complex
GPS Global Positioning System
GRA GPS Receiver/Processor Assembly
GSFC Goddard Space Flight Center
H
H/P high power
HA hour angle
HEF high efficiency (antenna)
HEMT high-electron-mobility (field-effect) transistor
HPBW half-power beamwidth
HRM high-rate (radio loss) model
HSB High (angular-tracking) Speed Beam Waveguide (antenna)
I
I/F interface
IDC IF to Digital Converter
IERS International Earth Rotation Service
IF intermediate frequency
ITRF IERS Terrestrial Reference Frame
ITU International Telecommunications Union
J-K
JPL Jet Propulsion Laboratory
L
L/P low power
LCP left (-hand) circular polarization
LNA low noise amplifier
LRM low-rate (radio loss) model
LSB least significant bit
M
M AP maximum a posteriori probability
MASER microwave amplification by stimulated emission of radiation
max maximum
M B medium bandwidth
MCD Maximum Likelihood Convolutional Decoder
M DA Metric Data Assembly
MDSCC Madrid (Spain) Deep Space Communications Complex
MED minimum error detection
MFR Multi-function Receiver
MGC manual gain control
min minimum
MOCC Mission Operations Control Center
mod modulation
MRT major range tone
N
NA; N/A not applicable
NASA National Aeronautics and Space Administration
NAV Navigation (Subsystem)
NB narrowband, narrow bandwidth
NCO numerically controlled oscillator
NMC Network Monitor and Control (Subsystem)
NOAA National Oceanic and Atmospheric Administration
NOCC Network Operations Control Center
NRZ non-return to zero
NRZ-L non-return to zero, level
NRZ-M non-return to zero, mark
NRZ-S non-return to zero, space
NSP Network Simplification Plan
NTIA National Telecommunications and Information Administration
NTK NOCC Tracking (Subsystem)
O
OQPSK offset quadriphase-shift keying
OVLBI Orbiting Very-long Baseline Interferometry
P
PCG Phase Calibration Generator (part of FTS)
PCM pulse-code modulation
PDF probability density function
portable document format (type or extension of computer file)
PDRVID pseudo-DRVID
PLL phase-locked loop
P M phase modulation
PN pseudo-random noise
POCC Project Operations Control Center
PSK phase-shift keyed
PTS Precision Telemetry Simulator
Q
QPSK quadriphase-shift keying
R
R/T real-time
RCP right circular polarization
rev revision
RF radio frequency
RH relative humidity
RID RF to IF Downconverter
RMDC Radio-Metric Data Conditioner
RMS; rms root-mean-square
RNG range
RNS Reliable Network Service
RRP Receiver Ranging Processor
RS Reed-Solomon (code), radio science
RSR Radio Science Receiver
rss, RSS root-sum-square
RTLT round-trip light time
RU range unit
S
S/C spacecraft
SCA Subsystem Control and Monitor Assembly
SEP Sun-Earth-Probe (angle)
SFU solar flux units (one SFU = 1 x 10^-22 W/m^2/Hz)
SNR signal-to-noise ratio
SPC Signal Processing Center
SPD S-Band Polarization Dipled (feedcone)
SRA Sequential Ranging Assembly
stowed With respect to an antenna, aimed near zenith for protection
from the wind.
sub, subcarr subcarrier
SYM symbol
SYS system
T
TBD to be determined
TDDS Tracking and Data Delivery System
TDRSS Tracking and Data Relay Satellite System
TEC total vertical electron content
TLM telemetry
TMOD Traking and Mission Operations Directorate
T_OP T sub OP (operating system temperature)
TXR transmitter or Transmitter Subsystem
U
U/L uplink
ULNA ultra low-noise amplifier
UPA Uplink Processor Assembly
URA Uplink Ranging Assembly
USO Ultra-Stable Oscillator
UTC Universal Time, Coordinated
V vacuum
VCO voltage controlled oscillator
VLBI very-long baseline interferometry
W
W/B, WB wideband
WD waveform distortion
X
X-EL cross-elevation
XMIT transmit
XRO X-band receive only (feedcone)
XTR X-band transmit-receive (feedcone)
Y
yr year
Z
ZDD Zero-delay Device
ZEN zenith