Mars Express Radio Science Team Stanford University Element Data Management Plan Prepared by: _____________________ Richard A. Simpson Concurrence by: _____________________ David P. Hinson Approved by: _____________________ G. Leonard Tyler Version 1.1 18 February 2005 Change Log |===============================================================| | Date |Version|Sections Changed| Description | |==========+=======+================+===========================| |2003-06-20| 1.0 | All |New document | |----------+-------+----------------+---------------------------| |2005-02-18| 1.1 | 1.1 |Updated version information| |----------+-------+----------------+---------------------------| |2005-02-18| 1.1 | 2.1 |Updated mission history | |----------+-------+----------------+---------------------------| |2005-02-18| 1.1 | 2.2.4 (para 4) |Revised discussion of BSR | | | | 4.2 |calibration | |----------+-------+----------------+---------------------------| |2005-02-18| 1.1 | 2.2.4 (para 5) |Updated requirements for | | | | |solar wind/corona studies | |----------+-------+----------------+---------------------------| |2005-02-18| 1.1 | 2.2.4 (page 9) |Updated Table | |----------+-------+----------------+---------------------------| |2005-02-18| 1.1 | 3.1 |Updated information on data| | | | 3.5 |paths; updated table with | | | | |better numbers after 1 year| |----------+-------+----------------+---------------------------| |2005-02-18| 1.1 | 3.2 |Updated data path info | | | | 3.4 | | | | | 3.6 | | |----------+-------+----------------+---------------------------| |2005-02-18| 1.1 | 4.6 |Updated status of: | | | | |EQUALIZ, TNF_READER, | | | | |MON_READER, BSR Processing,| | | | |and Two-Way Occultation | | | | |Processing | |----------+-------+----------------+---------------------------| |2005-02-18| 1.1 | 5.1 |Updated Table for MCH, BCK,| | | | |and BSP. Added BRO, ENB, | | | | |MFT, MCT, NMC, OPT, SRG, | | | | |and FRK. Added paragraph | | | | |about PI requests for | | | | |alternate formats/labeling | |----------+-------+----------------+---------------------------| |2005-02-18| 1.1 | 7 |Updates to figure | |===============================================================| TBD Items |===============================================================| | Section | Description | |===========+===================================================| | 2.2 |Several parameters in the tables (uplink and down- | | |link 3 dB angles, circuit losses, EIRP) | |-----------+---------------------------------------------------| | 2.2.4 |Procedure and configuration for egress occultations| |-----------+---------------------------------------------------| | 3.6 |Data formats, contents and volumes of NNO, NNC, ECH| |===============================================================| Contents 1 INTRODUCTION 1 1.1 PURPOSE 1 1.2 SCOPE 1 1.3 APPLICABLE DOCUMENTS 2 2 CONTEXT 3 2.1 MARS EXPRESS MISSION OVERVIEW 3 2.2 MARS EXPRESS RADIO SCIENCE OVERVIEW 3 2.2.1 Science Operations 6 2.2.2 Science Objectives 6 2.2.3 Instrument Modes 7 2.2.4 Data Requirements 8 3 DATA ACQUISITION 11 3.1 FILES OBTAINED BY REMOTE QUERY 11 3.2 FILES OBTAINED FROM MULTI-MISSION NAV 11 3.3 FILES OBTAINED FROM THE EIS WEB SITE 12 3.4 FILES OBTAINED FROM A JPL-BASED MEX DOM 12 3.5 FILES OBTAINED FROM NAIF 12 3.6 FILES OBTAINED FROM ESOC 13 4 DATA PROCESSING 14 4.1 QUICK LOOK PROCESSING 14 4.2 CALIBRATION DATA EXTRACTION 15 4.3 DETERMINISTIC FREQUENCY CALCULATION 15 4.4 STEERING AND SIGNAL PARAMETER ESTIMATION 17 4.5 ABEL INVERSION 17 4.6 SOFTWARE STATUS 18 5 ARCHIVING 19 5.1 RAW DATA ARCHIVE 19 5.2 CALIBRATED DATA ARCHIVE 20 5.3 REDUCED DATA ARCHIVE 21 6 ROLES AND RESPONSIBILITIES 22 6.1 G.L. TYLER (SUE PI) 22 6.2 D.P. HINSON (RADIO OCCULTATIONS) 22 6.3 R.A. SIMPSON (SURFACE SCATTERING AND DATA MANAGEMENT) 22 6.4 OTHER PERSONNEL 22 7 FACILITIES AND INSTITUTIONAL SUPPORT 23 8 REFERENCES 25 Abbreviations, Acronyms, and Symbols a impact parameter A~ amplitude estimate APS average power spectra APS' calibrated average power spectra ASCII American Standard Code for Information Interchange AX ASCII extract (from binary file) B byte BWG beam waveguide {c0, ..., c3} frequency coefficients for steering CD compact disc CD-R compact disc recordable chan channel CLR closed loop reception d(r) density as a function of radius D/L downlink D8W DSN eight-week schedule dB decibel dBm decibel with respect to one milliwatt DC direct current (zero frequency) deg degree df~ estimated width of bistatic radar echo signal DKF DSN keyword file DOM DSMS Deep Space Mission System DSN Deep Space Network DVD Digital Versatile Disc DVD-R Digital Versatile Disc - Recordable e(r) electron density as a function of radius ECH channelized spacecraft engineering data ECH_READER program to extract certain channels from ECH data EIRP effective isotropic radiated power EIS JPL Information Services EOP Earth orientation parameters EQUALIZ program to equalize filter response ESA European Space Agency ESOC European Space Operations Centre f~ frequency estimate f0 carrier frequency fg classical frequency correction (from geometry) FND program to filter and decimate fr general relativity frequency correction FY fiscal year G(a) bending angle as a function of impact parameter GB gigabyte Gbs gigabits per second HEF high efficiency (antenna) HGA high gain antenna HIST program to plot histograms of data samples HSB high-speed beam waveguide (antenna) Hz hertz ID identifier IGM Institut fuer Geophysik und Meteorologie ION ionosphere media calibration data JPL Jet Propulsion Laboratory K kelvin kHz kilohertz kw kilowatt LCP left circular polarization LIT light time file LOOK program to compute average power spectra LSK leap seconds kernel m meter MaRS Mars Express Radio Science Mbs megabits per second MDOM MEX DOM MEX mars Express MHz megahertz MON DSN monitor data MON_READER program to extract certain channels from MON data MRS Mars Express Radio Science N/A not available; not applicable n(r) refractive index as a function of radius NAIF Navigation and Ancillary Information Facility NASA National Aeronautics and Space Administration NAV Navigation (team) NNC New Norcia closed loop data NNO New Norcia open loop data ODF orbit data file OLR open loop reception ONE-D one-way dual frequency ONE-S one-way single frequency OPT orbit propagation and timing generation OSCARX multi-mission NAV server p(r) pressure as a function of radius P~ power estimate {p0, ..., p3} phase coefficients from RSR {P0, ..., P4} phase coefficients of simulated oscillator PCK planetary constants kernel PDS Planetary Data System PI principal investigator POWER program to compute average samples vs time POWERFIT program to estimate amplitude and frequency PREPNNO preprocessing program for New Norcia data PREPRSR preprocessing program for DSN data PSA Planetary Science Archive (ESA) Pt spacecraft transmitter power QS-M RSR_MASTER_QueryServer QS-R Mgs_CDR_QueryServer QS-T Trk_trk1_QueryServer r radius RCP right circular polarization RSSG Radio Science Systems Group RSR radio science receiver rsr01 output from PREPRSR or EQUALIZ rsr02 output from FND (same format as rsr01) rsr03 output format from STEER (sam format as rsr01) s second S-Band band centered on approximately 2 GHz SCK spacecraft clock conversion file SOE sequence of events SOPC science operations planning computer SPK spacecraft/planetary ephemerides STARLab Space, Telecommunications, and Radioscience Laboratory SUE Stanford University Element T-p(r) temperature-pressure profile vs radius T(r) temperature profile vs radius TBD to be determined TCK spacecraft attitude kernel TNF tracking and navigation file TNF_READER program to extract certain channels from TNF data TRO tropospheric media calibration file Tsys system temperature TWO-D two-way dual frequency TWO-S two-way single frequency U/L uplink uso on board oscillator VPN Virtual Private Network w watt WEA DSN meteorological data X-Band band centered on approximately 8 GHz 1 Introduction 1.1 Purpose For purposes of proposal and readiness evaluation prior to Mars Express (MEX) Phase E, the first version (1.0) of this document described plans for data acquisition, processing, and archiving by the Stanford University Element (SUE) of the MEX Radio Science (MaRS) Team. For purposes of data use during and after the mission, later versions of this document (e.g., 1.1) describe the data acquisition, processing, and archiving actually performed by the SUE of the MEX MaRS Team. 1.2 Scope With regard to Mars Express Radio Science and ancillary data originating within the NASA Deep Space Network (DSN) and Jet Propulsion Laboratory (JPL) this document describes: Transfer of radio science and ancillary data from JPL and DSN sources to Stanford; Processing of some of those files by the SUE; and Generation and delivery of archival volumes of both the original data and partially processed results (calibrated data) to the MaRS Principal Investigator (PI), Martin Paetzold, Universitaet zu Koeln. The document also describes: SUE acquisition of certain data files obtained by the MaRS PI from ESA sources; and Processing of those files by the SUE, and delivery of the partially processed results (calibrated data) to the MaRS PI. The document does not discuss: Strategies for maximizing science utility of and detailed planning for MaRS observations; Handling of non-JPL/DSN MaRS files that are not germane to Stanford investigations; Transfer of data files from the MaRS PI to the European Space Agency (ESA) Planetary Science Archive (PSA); Transfer of ESA PSA files to the NASA Planetary Data System (PDS) 1.3 Applicable Documents [REF1] Paetzold, M., Rosetta, Mars Express, Venus Express Archive Generation, Validation, and Transfer Plan, MEX-MRS-IGM-IS-3019, Issue 3, Revision 2, 20 May 2003 [REF2] Tyler, G.L., Proposal to the California Institute of Technology Jet Propulsion Laboratory for Operations Phase E, Mars Express Radio Science Experiment, Stanford University Element, 27 May 2003. [REF3] Planetary Data System Standards Reference, JPL Document D-7669, Part 2, Version 3.5, 15 October 2002. [REF4] Planetary Data System Data Dictionary Document, JPL Document D-7116, Rev. D, 15 July 1996. [REF5] DSMS Telecommunications Link Design Handbook: 70-m Subnet Telecommunications Interfaces, Document 810-005, Rev. E, Section 101, Pasadena, CA: Jet Propulsion Labroratory, 30 November 2000. [REF6] Mars Express Orbiter Radio Science Flight Operations Manual/Experiment User Manual, MEX-MRS-IGM-MA-3008, Issue 1, Revision 1, 03 March 2003. [REF7] DSMS Telecommunications Link Design Handbook: 34-m HEF Subnet Telecommunications Interfaces, Document 810-005, Rev. E, Section 103, Pasadena, CA: Jet Propulsion Laboratory, 30 November 2000. [REF8] DSMS Telecommunications Link Design Handbook: 34-m BWG Subnet Telecommunications Interfaces, Document 810-005, Rev. E, Section 104, Pasadena, CA: Jet Propulsion Laboratory, 30 November 2000. 2 Context Phase E operations of the SUE represent part of the MaRS investigation of the MEX mission. In order to understand the SUE data management plan, some context is required. 2.1 Mars Express Mission Overview The MEX spacecraft was launched on 2 June 2003 from the Baikonur launch facility in Kazakhstan. After a six-month cruise, the spacecraft separated from the Beagle 2 lander and went into orbit around Mars. Over a period of months, the orbit was adjusted to a final inclination of 87 deg, a period of 6.7 hours, and distances from Mars' surface between 250 km (pericenter) and 11500 km (apocenter). Each orbit includes an Observation Phase of 0.5-1.0 hours centered on pericenter, during which many of the six onboard instruments collect data from the planet, and a Communications Phase, during which the spacecraft high-gain antenna (HGA) is aimed toward Earth for transmission of data and reception of commands. Objectives of the mission include: Interaction of the atmosphere with the interplanetary medium Global atmospheric circulation and high-resolution mapping of atmospheric composition Improved understanding of the surface-atmosphere interaction Global photogeology at 10 m resolution Global mineralogical mapping of the surface at 100 m resolution Detection of subsurface structures at km-scale HGA pointing, instrument panel pointing, and the rotational axis of the solar panels define three orthogonal axes of a right-hand coordinate system. As negotiated with mission planners and other instrument teams, MaRS will interrupt the Communications Phase (and, less often, the Observation Phase) to gather radio science data. The work described in this document addresses the first three mission objectives listed above. 2.2 Mars Express Radio Science Overview The Mars Express Radio Science instrument includes elements on both the spacecraft and ground. The spacecraft radio system includes a dual-band (S/X) transponder and a high-gain antenna with a body-fixed parabola. The ground element includes an ESA station near New Norcia (Australia) and parts of three NASA Deep Space Network complexes near Canberra (Australia), Madrid (Spain), and Barstow (California). Spacecraft radio system performance is summarized in the table below [REF6]: |=========================================================| | | S-Band | X-Band | |=================================+===========+===========| |Antenna Diameter (m) | 1.73 | 1.73 | |Nominal Uplink Frequency (MHz) | 2100. | 7100. | |Uplink Gain (dB) | 28.60 | 39.18 | |Uplink 3 dB Angle (deg) | TBD | TBD | |Receiver System Temperature (K) | 190. | 300. | |Noise Power Density (dBm/Hz) | -175.81 | -173.83 | |Nominal Downlink Frequency (MHz) | 2300. | 8400. | |Downlink Gain (dB) | 29.56 | 41.43 | |Downlink 3 dB Angle (deg) | TBD | TBD | |Transmitter Power (w) | 5.0 | 65.0 | |Circuit Losses (dB) | 5.5 | 3.0 | |=========================================================| New Norcia ground station capabilities are summarized in the table below [REF6]: |=========================================================| | | S-Band | X-Band | |=================================+===========+===========| |Antenna Diameter (m) | 35. | 35. | |Nominal Uplink Frequency (MHz) | 2100. | 7100. | |Uplink Gain (dB) | 53.48 | 64.06 | |Uplink 3 dB Angle (deg) | 0.31 | 0.09 | |Transmitter Power (w) | 20000. | 2000. | |Circuit Losses (dB) | TBD | TBD | |EIRP (dBm) | TBD | TBD | |Nominal Downlink Frequency (MHz) | 2300. | 8400. | |Downlink Gain (dB) | 55.75 | 67.00 | |Downlink 3 dB Angle (deg) | 0.29 | 0.08 | |Receiver System Temperature (K) | 71. | 62. | |Noise Power Density (dBm/Hz) | -180.09 | -180.68 | |=========================================================| DSN 34-m high-efficient (HEF) antenna nominal performance is shown in the table below [REF7]: |=========================================================| | | S-Band | X-Band | |=================================+===========+===========| |Antenna Diameter (m) | 34. | 34. | |Nominal Uplink Frequency (MHz) | N/A | 7145. | |Uplink Gain (dB) | N/A | 67.1 | |Uplink 3 dB Angle (deg) | N/A | 0.0778| |Transmitter Power (w) | N/A | 20000. | |Circuit Losses (dB) | N/A | 0.25 | |EIRP (dBm) | N/A | 139.9 | |Nominal Downlink Frequency (MHz) | 2295. | 8420. | |Downlink Gain (dB) | 56.00 | 68.3 | |Downlink 3 dB Angle (deg) | 0.242 | 0.0660| |Receiver System Temperature (K) | 40. | 20. | |Noise Power Density (dBm/Hz) | N/A | N/A | |=========================================================| DSN 34-m beam waveguide (BWG) and high-speed beam waveguide (HSB) antenna nominal performance is shown in the two tables below [REF8]. The second table shows differences in frequency coverage among the BWG and HSB systems. |=========================================================| | | S-Band | X-Band | |=================================+===========+===========| |Antenna Diameter (m) | 34. | 34. | |Nominal Uplink Frequency (MHz) | 2115. | 7145. | |Uplink Gain (dB) | 56.1 | 67.1 | |Uplink 3 dB Angle (deg) | 0.263 | 0.0778| |Transmitter Power (w) | 20000. | 4000. | |Circuit Losses (dB) | TBD | TBD | |EIRP (dBm) | 128.5 | 133.1 | |Nominal Downlink Frequency (MHz) | 2295. | 8420. | |Downlink Gain (dB) | 56.8 | 68.2 | |Downlink 3 dB Angle (deg) | 0.242 | 0.0660| |Receiver System Temperature (K) | 30. | 25. | |Noise Power Density (dBm/Hz) | N/A | N/A | |=========================================================| In the table below entries in the uplink (U/L) columns give maximum available uplink transmitter power; no entry means no transmitter for that band. Entries in the downlink (D/L) columns give the number of low noise amplifiers and receiver front ends available for the band; no entry means no low noise receiving capability. Ka-Band entries are included for completeness but are not relevant for MaRS. |====================================================| | | S-Band | X-Band | Ka-Band | |----------------+-----------+-----------+-----------| | Antenna | Type | U/L | D/L | U/L | D/L | U/L | D/L | | | | (kw)| | (kw)| | (kw)| | |=========+======+=====+=====+=====+=====+=====+=====| | DSS 24 | BWG | 20 | 1 | | 1 | | | | DSS 25 | BWG | | | 4 | 1 | 0.8 | 1 | | DSS 26 | BWG | | | 4 | 2 | | | | DSS 27 | HSB | 0.2 | 1 | | | | | | DSS 34 | BWG | 20 | 1 | 4 | 1 | | | | DSS 54 | BWG | 20 | 1 | 4 | 1 | | | |====================================================| DSN 70-m antenna nominal performance is summarized in the table below [REF5]: |=========================================================| | | S-Band | X-Band | |=================================+===========+===========| |Antenna Diameter (m) | 70. | 70. | |Nominal Uplink Frequency (MHz) | 2115. | 7145. | |Uplink Gain (dB) | 62.7 | 72.9 | |Uplink 3 dB Angle (deg) | 0.128 | 0.0378| |Transmitter Power (w) | 20000. | 20000. | |Circuit Losses (dB) | 0.3 | 0.45 | |EIRP (dBm) | 134.4 | 145.4 | |Nominal Downlink Frequency (MHz) | 2300. | 8420. | |Downlink Gain (dB) | 63.34 | 74.16 | |Downlink 3 dB Angle (deg) | 0.118 | 0.0320| |Receiver System Temperature (K) | 16. | 19. | |Noise Power Density (dBm/Hz) | N/A | N/A | |=========================================================| 2.2.1 Science Operations The Mars Express radio link to Earth is used for science investigations in two ways. 2.2.1.1 Radiometric Observation The distance between and relative velocity of the spacecraft and a tracking station on Earth can be determined by measuring the propagation time (most accurately, the two-way round-trip time) and Doppler shift, respectively. For example, additional gravitational attraction of a mass concentration will affect the trajectory of the spacecraft, inducing a Doppler shift. The signature of the Doppler shift, in conjunction with the observational geometry, allows inference of the location of the mass concentration and its magnitude. 2.2.1.2 Media Dispersion The properties of intervening media may be inferred from time and frequency effects on the propagating signal. Refractivity increases with the density of a neutral gas; it decreases in a plasma as the electron density increases. Both positive and negative refractivity can be observed when the radio path intercepts a planet's atmosphere (including its ionosphere). Propagation through the (turbulent) solar corona or reflection from a rough planetary surface both cause Doppler broadening of the signal. 2.2.2 Science Objectives Science objectives of the MaRS Team are as follows: (a) Sounding of Mars' neutral and ionized atmosphere by radio occultation (b) Improvement of the gravity field, especially regarding anomalies (c) Determination of the mass of Phobos (d) Measurement of Mars' surface dielectric constant using bistatic radar (e) Sounding of the solar corona Among the objectives above, the SUE will address items (a) and (d) directly and assist the MaRS Team in acquiring DSN data to meet the other objectives. 2.2.3 Instrument Modes Four instrument 'modes' have been defined for MaRS on the spacecraft [REF6]. In all cases the optimum radio science data are obtained when the spacecraft modulation index is minimized--except for the ranging subchannel. One-way single frequency (ONE-S): The spacecraft uses its internal oscillator and transmits an X-band carrier. One-way dual frequency (ONE-D): Same as ONE-S except that both X-band and S-band are transmitted. Two-way single frequency (TWO-S): An X-band signal is transmitted from the ground, is echoed by the spacecraft at X-band, and is received on the ground. Two-way dual frequency (TWO-D): Same as TWO-S except that the spacecraft echoes at both X- and S-band. For sounding of the solar corona, the uplink from the ground may be at S-band. For each spacecraft mode, there are several options for reception on the ground. In some cases, more than one may be selected. Open Loop and Closed Loop Reception: With open loop reception (OLR), the spacecraft signal is down-converted to a frequency range of a few Hz to a few tens of kHz, sampled, and stored for later analysis. OLR effectively preserves all details of the signal within the bandwidth captured, but at a significant cost in data volume. In closed loop reception (CLR), a phase lock loop (or equivalent device) tracks the signal amplitude and frequency; its output is recorded at intervals on the order of tenths of a second. CLR is very efficient in terms of data volume, but it works poorly when the signal is dynamic and is of no use when the signal is spread. Polarization: The default polarization transmitted by the spacecraft is right-circular. During interaction with targets en route to Earth, the signal's polarization may be altered. Randomization from Faraday rotation is expected during deep probing of the solar corona; both deterministic (Fresnel) polarization changes and random depolarization are expected in scattering from Mars' surface. DSN 70-m antennas are equipped to receive both RCP and LCP at both S- and X-band. DSN 34-m antennas can receive one polarization at S-band and one polarization at X-band. New Norcia can receive two signals simultaneously; the user chooses whether they are two polarizations in the same band or a single polarization in each of two bands. 2.2.4 Data Requirements Among the MaRS science objectives above, the SUE will address items (a) and (d) directly and will assist the MaRS Team in acquiring DSN data to meet the other objectives. The MaRS PI will, in turn, provide Stanford with New Norcia data suitable for incorporation into the SUE (a) and (d) investigations. Atmospheric Occultation Immersion: The spacecraft will be in the TWO-D mode and open loop receivers on the ground will sample S-RCP and X-RCP receiver outputs at rates on the order of 2000 16-bit I, 16-bit Q (complex) samples per second. Receivers will be tuned using two-way closed-loop receiver predictions; analysis will require the uplink (transmitted) tuning profile. Atmospheric Occultation Emersion: Details of this operation remain TBD. The configuration could be identical to that used for Atmospheric Occultation Immersion. The spacecraft phase lock loop likely will not lock up quickly enough to allow analysis of the (lower) neutral atmosphere, but the data should be good for the egress ionosphere. Alternatively, the spacecraft could be operated in ONE-D mode. In this mode the spacecraft signal frequency is less stable than when in the TWO-D mode, but there are no data gaps as a result of the lock-up process. Surface Dielectric Constant: The spacecraft will be in ONE-D mode and open loop receivers on the ground will sample S-RCP, S-LCP, X-RCP, and X-LCP at rates up to 25000 I/Q pairs per second. Each I and each Q will have 8- or 16- bits, depending on the observation. When four channels cannot be captured (as at New Norcia, where the limit is two), the spacecraft may operate in ONE-S mode with corresponding simplification on the ground. Since absolute amplitude calibration of each channel is required during analysis, system temperature monitoring through CLR receivers is needed. CLR's are used to turn noise diodes on and off immediately before and after bistatic observations, providing calibration of the radiothermal noise background. The noise diodes themselves and "cold" sky are calibrated against ambient loads in the pre- and post-pass periods. Only two CLR's are usually available; they must be switched between S- and X-band in order to control the four noise diodes. Non-SUE Investigations: Improved gravity modeling (b), investigation of gravity anomalies (b), and determination of the mass of Phobos (c) are preferably based on TWO-D data, though TWO-S may be sufficient in some circumstances such as when the data collection period is short compared with expected plasma changes along the propagation path. These investigations require CLR data from the ground station; one polarization (RCP) is sufficient. Solar corona data (e) are best when the spacecraft is in TWO-D mode. Two polarizations in each band and both OLR and CLR operation are preferred when the resources are available. The table below summarizes the data needed, the sources (based primarily on SUE experience with Mars Global Surveyor), and the objectives associated with each data type. The level of need varies among products. Where the need is less than a requirement, the column shows '?'. |===================================================| | Data Type |Source| Science | | | | Objectives| |================================+======+===========| |Radio Science Receiver (RSR) | QS-R | a d e | | open loop data records | | | |--------------------------------+------+-----------| |Tracking and Navigation (TNF) | QS-T | a b c ? e | | data (TRK-2-34) | | | |--------------------------------+------+-----------| |Orbit Data File (ODF) |OSCARX| b c e | |--------------------------------+------+-----------| |DSN Monitor Data (MON) | QS-M | d | |--------------------------------+------+-----------| |Ionosphere Calibration (ION) |OSCARX| ? ? ? ? | |--------------------------------+------+-----------| |Troposphere Calibration (TRO) |OSCARX| ? ? ? ? | |--------------------------------+------+-----------| |DSN Meteorology Data (WEA) |OSCARX| ? ? ? ? | |--------------------------------+------+-----------| |Channelized Spacecraft | ESOC | ? | | Engineering Data (ECH) | | | |--------------------------------+------+-----------| |Earth Orientation Parameters | EIS | a ? ? ? | | (EOP) | | | |--------------------------------+------+-----------| |Lighttime Files (LIT) | MDOM | ? | |--------------------------------+------+-----------| |Orbit Propagation and Timing | ESOC | ? | | Generation Files (OPT) | | | |--------------------------------+------+-----------| |Sequence of Events Files (SOE) | MDOM | ? d ? | |--------------------------------+------+-----------| |DSN Keyword Files (DKF) | MDOM | ? d ? | |--------------------------------+------+-----------| |DSN 8-Week Schedule (D8W) | MDOM | b c ? e | |--------------------------------+------+-----------| |Spacecraft Attitude Kernels | NAIF | ? ? ? d ? | | (TCK) | | | |--------------------------------+------+-----------| |S-P Kernels (SPK) | NAIF | a d e | |--------------------------------+------+-----------| |Spacecraft Clock Conversion File| NAIF | a b c d e | | (SCK) | | | |--------------------------------+------+-----------| |Planetary Constants Kernel (PCK)| NAIF | a b c d e | |--------------------------------+------+-----------| |Leap Second Kernels (LSK) | NAIF | a b c d e | |--------------------------------+------+-----------| |New Norcia Open Loop (NNO) | ESOC | ? ? | |--------------------------------+------+-----------| |New Norcia Closed Loop (NNC) | ESOC | ? ? | |===================================================| Sources: QS-R RSR_MASTER_QueryServer (SOPC) QS-M Mgs_CDR_QueryServer (SOPC) QS-T Trk_trk1_Query Server (SOPC) OSCARX Multi-Mission NAV server (SOPC) ESOC ESOC data system via MaRS PI EIS eis.jpl.nasa.gov web site (SOPC) MDOM JPL-supported MEX DOM or equivalent (SOPC) NAIF naif.jpl.nasa.gov anonymous ftp SOPC MGS Science Operations Planning Computer or equivalent 3 Data Acquisition 3.1 Files Obtained by Remote Query Files needed for MaRS which have been obtained by query during the MGS era include the following, where the data type acronym is defined in the table above. MGS RSR, TNF, and MON data are being transferred over a Virtual Private Network (VPN). For MaRS it has been more convenient to obtain RSR's using a remote JPL workstation (rsops2) maintained by the Radio Science Systems Group (RSSG), then transferring the data to Stanford via sftp over the Internet. Number of Events and Mission Data Volume are calculated for the primary mission (2004-2005) only. |======================================================| |Data| Science | Data Rate|Chans| Time|Number|Mission| |Type| Objective | | | per | of | Data | | | | | |Event|Events| Volume| | | |(B/chan/s)| | (s) |[REF6]| (GB) | |====+===========+==========+=====+=====+======+=======| | RSR| a | 10000. | 2 | 1200| 160 | 4. | | TNF| a | 1000. | 1 |21600| 160 | 3.5 | | TNF| c | 1000 | 1 |21600| 2 | 0.04| | RSR| d | 100000. | 4 | 7200| 20 | 144. | | TNF| d | 1000. | 1 |21600| 20 | 0.5 | | MON| d | 400. | 2 |21600| 20 | 0.4 | | RSR| e | 10000. | 4 | 7200| 60 | 43. | | TNF| e | 1000. | 1 |21600| 60 | 1.3 | |======================================================| B = bytes 3.2 Files Obtained from Multi-Mission NAV The following files have been collected through the JPL Multi-Mission Navigation Team server oscarx during MGS. Similar access has been obtained for MaRS. Data volume is negligible compared with the data types above (e.g., RSR). ODF's are typically released five times per week, ION's once per week, TRO's once per week, and WEA's twice per week. |=========================================================| |Data| Science | Number of Files | Typical File Size | |Type| Objective | in Primary Mission | (MB) | |====+===========+====================+===================| | ODF| c e | 700 | 0.1 | | ION| c e | 100 | 0.05 | | TRO| c e | 100 | 0.05 | | WEA| c e | 300 | 0.5 | |=========================================================| 3.3 Files Obtained from the EIS Web Site Earth Orientation Parameter files can be downloaded from eis.jpl.nasa.gov. The files are released at the rate of approximately four per week; their volume is negligible compared with files such as the RSR. |=========================================================| |Data| Science | Number of Files | Typical File Size | |Type| Objective | in Primary Mission | (MB) | |====+===========+====================+===================| | EOP| a c | 400 | 0.5 | |=========================================================| 3.4 Files Obtained from a JPL-based MEX DOM The following files are helpful in setting up experiments and in managing data. For MGS Stanford obtains these from the MGS DOM; the source for MaRS is the MEX DOM. These files have negligible volume compared to files like the RSR. |=========================================================| |Data| Science | Number of Files | Typical File Size | |Type| Objective | in Primary Mission | (MB) | |====+===========+====================+===================| | LIT| ? | 1 | 1.0 | | SOE| ? | 300 | 0.5 | | DKF| d | 300 | 0.1 | | D8W| a c d e | 100 | 0.01 | |=========================================================| 3.5 Files Obtained from NAIF The following files are available through the NAIF anonymous ftp server naif.jpl.nasa.gov. Files are released on about the 15th of each month covering ther previous month. |==========================================| |Data| Science | Data Rate|Number|Mission| |Type| Objective | | of | Data | | | | | Files| Volume| | | |(MB/month)| | (GB) | |====+===========+==========+======+=======| | SPK| a d e | 13. | 24 | 0.3 | | TCK| a c d ? | 2. | 24 | 0.05 | | SCK| a c d e | N/A | N/A | <0.01 | | PCK| a c d e | N/A | N/A | <0.01 | | LSK| a c d e | N/A | N/A | <0.01 | |==========================================| B = bytes 3.6 Files Obtained from ESOC The following files must be obtained from ESOC. New Norcia data are basic input to the atmospheric, ionospheric, and surface scattering studies, but their content, format, and volume are not known at this time. Spacecraft Engineering Data may be important in bistatic radar if the MEX transmitter power varies significantly (but this is not expected). The Lighttime File is used in some predictions, although the same information can be obtained more laboriously from the OPT. Information in the OPT can be derived from the SPK. The ESOC SOE presumably would cover the entire mission whereas the SOE listed above (Section 3.4) is limited to DSN-supported activities. |=========================================================| |Data| Science | Number of Files | Typical File Size | |Type| Objective | in Primary Mission | (MB) | |====+===========+====================+===================| | NNO| a d | TBD | TBD | | NNC| a d | TBD | TBD | | ECH| ? | TBD | TBD | | LIT| ? | 1 | TBD | | OPT| ? | 100 | TBD | | SOE| ? ? | 100 | TBD | |=========================================================| 4 Data Processing The following sections describe the typical steps in processing open loop data to obtain radio occultation temperature-pressure profiles of Mars' atmosphere, profiles of electron density for the ionosphere, and reflectivity estimates from surface scatter. RSR is taken to be the generic input data type; when more details are known about NNO formats and content, the procedures will be adapted for that data type. 4.1 Quick Look Processing Data processing takes place in several steps. For open loop RSR data, a 'quick-look' processing step provides immediate information on data quality. PREPRSR is a program which converts the RSR integer I/Q samples to a standard double-precision complex value format; it also saves the distribution of I and Q values for later plotting as a histogram. EQUALIZ digitally filters the floating point samples. Input data bandwidth can be reduced, and 'equalization' can be applied to correct for a 'colored' spectrum at the input. EQUALIZ is used only for bistatic radar data, where the signals are broad and drift within the passband during the course of the experiment. The rsr01 output from EQUALIZ (or PREPRSR in occultation processing) can then be used to calculate plots of average sample power (1 sec averages) versus time and power spectra typically averaged over 60 seconds. --------- ------ Histograms RSR --->| PREPRSR |--->| HIST | of --------- ------ I/Q Samples | | rsr01 v / --------- / ------- Power | EQUALIZ |--->| POWER |--> vs --------- | ------- Time Plot | | ------- Average |->| LOOK |--> Power Spectra | ------- (APS) | v ----- | FND | ----- | v rsr02 Digitally Filtered Complex Time Samples In the bistatic radar analysis, there is usually no reduction in the data bandwidth, and Average Power Spectra (APS) become the input to later processing. It is assumed that a PREPNNO program can be written for New Norcia data that mimics the functions of PREPRSR and provides output in the standard rsr01 format. 4.2 Calibration Data Extraction In bistatic radar analysis, Average Power Spectra (APS) are obtained during pre- and post-calibration periods when the receivers are looking at "cold" sky (zenith), when they are connected to ambient loads, and when noise diode energy is injected in both of the previous configurations. The system temperature of each receiver Tsys can be obtained by comparing the cold sky power against the ambient load; the value of each noise diode may also be determined. Immediately before and after the bistatic radar observation, the noise diodes are turned on; this injects a known amount of additional background power from which the operating Tsys can be derived. Finally, the power in the bistatic radar echo signal can be determined by comparison against the background noise. Amplitude calibration can be improved with knowledge of the output power Pt of the spacecraft transmitter, which should be obtainable in the spacecraft engineering data stream ECH using an ECH_READER tool. ------------ ECH --->| ECH_READER |------------> Pt ------------ Processing of two-way radio occultation data requires knowledge of the uplink transmitter phase or frequency f0, which is carried in the TNF. ------------ TNF --->| TNF_READER |------------> f0 ------------ 4.3 Deterministic Frequency Calculation The apparent frequency of the baseband signal recorded on Earth depends on several factors. In the simple case (one-way transmissions from the spacecraft) these include: frequency of the spacecraft oscillator position and motion of the spacecraft at transmit time general relativistic effects (Sun's gravitational field) position and motion of the antenna on Earth at receive time tuning and mixing of the Earth based receiver For two-way observations the position and motion of the transmitting antenna on Earth, the tuning profile of the uplink signal, and the turn-around ratio in the spacecraft electronics are substituted for the spacecraft oscillator frequency. Each of these contributions can be calculated from information in available data products. The first four yield sets of polynomial coefficients which can be used to approximate part of the baseband signal frequency (f = c0 + c1*t +c2*t^2 + c3*t^3). These coefficients are typically computed at one second intervals; past experience shows them to be accurate at the millihertz level. Tuning and mixing of the receiver on Earth are described by offsets and by sets of coefficients for a phase polynomial computed and carried along in the RSR data record (p = p0 + p1*t + p2*t^2 + p3*t^3). uso | fg v ---------------------- / ---------- EOP --->| GEOMETRY CALCULATOR: |--->| FREQUENCY| SPK --->|S/C, RELATIVITY, EARTH| | |<--- RSR TCK --->| ROTATION, LIGHT TIME |--->|CALCULATOR| ---------------------- \ ---------- | fr | v v bsr-g {c0, c1, ...} In the figure above fg is the frequency correction based on classical Doppler effects (including motion of the spacecraft and Earth antenna, including Earth rotation), fr is a general relativistic correction for the change in the Sun's gravitational potential as the signal propagates from Mars to Earth, and uso is the current estimate of spacecraft oscillator frequency, based on previous one-way observations or the two-way uplink tuning profile (f0, in the previous figure) adjusted appropriately for transmitter motion and the spacecraft transponder turn-around ratio. RSR, on the right, denotes the ground receiver tuning information (and, implicitly, the mixing design of the receiver), stored in the RSR file along with the open loop data samples. TCK represents spacecraft attitude, a Doppler correction of marginal significance on MGS where the HGA is at the end of a 3-m boom; the MaRS HGA is attached to the spacecraft bus, and the Doppler effects are likely to be insignificant. This correction may be ignored. In bistatic radar analysis, calculation of the absolute downlink frequency is not usually required. During the experiment, the receiver bandwidth is chosen so that both the surface echo and a weak signal reaching Earth directly via one of the HGA sidelobes are captured. It is sufficient in the great majority of cases to know frequencies in the echo spectrum relative to the carrier frequency and not necessary to know either absolutely. Instead, the GEOMETRY CALCULATOR synthesizes the bistatic viewing geometry (including the HGA pointing) and provides parameters such as angle of incidence at the specular reflection point and expected polarization ratio for an assumed dielectric constant. In a separate step, the frequency difference between the carrier and echo can be calculated. 4.4 Steering and Signal Parameter Estimation With the coefficient sets {c0, c1, c2, c3} and {p0, p1, p2, p3} one can synthesize a 'software' representation of a sinusoid with phase P = P0 + P1*t + P2*t^2 + P3*t^3 + P4*t^4 where the frequency contribution {ci} has been integrated to give phase. The phase function is continuous across time intervals (as coefficients change), and the accumulating phase can be subtracted from the (accumulating) phase of the data samples rsr02. If the coefficients are a perfect match to the data, the result is a constant phasor (DC). If the match is not perfect (as would be expected when the radio path passes through Mars' atmosphere), the phasor rsr03 is a measure of the phase advance or retardation caused by the plasma or neutral gas, respectively. In radio engineering, this process is known as 'mixing'; at Stanford we have adopted the term 'steering', since the resultant can be directed to any frequency by adding a bias to the c0 coefficient. {c0,c1,...,c3} {p0,p1,...,p3} | v rsr03 ------- / ---------- rsr02 --->| STEER |---->| POWERFIT |---> f~, A~ ------- ---------- The steered data rsr03 can be Fourier transformed. A sinc function can be fitted to the carrier using program POWERFIT; the fitting parameters yield estimates of the carrier amplitude A~ and frequency f~ as a function of time. In bistatic radar data processing, steering is rarely used. After removing the noise baseline from the APS', power in the echo P~ can be calculated directly from its spectrum, and width of the echo signal df~ can be obtained using one of several smoothing and/or fitting algorithms. The ratio of the P~ values from the RCP and LCP channels plus knowledge of the geometry yields the effective dielectric constant of the surface material [Simpson and Tyler, 2001]. df~ is taken to be proportional to the surface roughness except when the HGA beamwidth does not fully illuminate the scattering surface. Calculation of the cross-spectrum (from rsr01 data in two polarizations) allows estimation of the polarized and unpolarized fractions of the echo power. 4.5 Abel Inversion The remaining steps in deriving temperature-pressure profiles for the neutral atmosphere are based on a procedure developed by Fjeldbo et al. [1971] and summarized by Tyler et al. [1992]. The frequency or phase estimates f~ are converted to a measure of bending angle G as a function of impact parameter a using reasonable assumptions of symmetry and the reconstructed experimental geometry. An Abel transform of G(a) yields a unique solution for refractive index n(r) as a function of radius r from the planet's center. If the composition of the atmosphere and the refractive indices of the major components are known, n(r) can be converted to d(r), the mass density of the atmosphere as a function of r. Assuming hydrostatic equilibrium and the ideal gas law allows inference of p(r) and T(r), the pressure and temperature profiles of the atmosphere. For profiles of the ionosphere, n(r) is obtained as above. Then a standard translation [Yeh and Liu, 1972] can be used to obtain the electron density profile e(r) from the refractive index. 4.6 Software Status Most of the software mentioned above exists and is operational for Mars Global Surveyor. Certain file naming and directory conventions will need to be adapted for MaRS. The following were identified in the previous version of this document as needing additional work: PREPNNO This program does not exist and cannot be designed until details of the New Norcia formats become available. PREPNNO converts raw data to a standard format; it is expected to be modeled on the operational PREPRSR. EQUALIZE This program has been implemented by adding an "equalizing" option to the existing FND program TNF_READER This program extracts a few numbers from a larger file; it is operational and has been used to process more than 40 MaRS radio occultations. MON_READER This program extracts a few numbers from a larger file. Because of the changes in bistatic radar calibration, it is no longer needed. ECH_READER This program extracts a few numbers from a larger file. It does not exists but is not expected to require much work. bsr-g Software exists to calculate the bistatic radar observing geometry, including the boresight pointing of the spacecraft antenna. But software to calculate the illumination of the surface (the HGA footprint) does not. Such a program would be useful in interpretation, but it will take some time to develop. The illumination pattern is not required for generation of the products described in this document. BSR Processing The modules for processing bistatic radar data have been written and used on MaRS bistatic radar data collected in May 2004. Their use is labor intensive and they have not been organized into a processing pipeline. The process will be streamlined as efficiencies are identified during coming months. Two-Way Occultation Processing: Processing of two-way radio occultation data is now routine; over 40 temperature-pressure profiles have been generated using MaRS data. Registration of Dual-Frequency Profiles: The ability to acquire profiles of electron density and neutral atmosphere profiles is improved by having observations at two frequencies--especially in the case of the former. The procedure for resolving differences is understood but not being used for MGS, which only operates at X-band. To date no S-band MaRS data have been processed to Level 2. 5 Archiving There are three levels of data products suitable for archive from SUE operations: raw and ancillary data acquired from JPL/DSN calibrated data derived from the above and from NNO reduced data derived from the calibrated data 5.1 Raw Data Archive The raw data archive will be generated as the files are acquired from JPL/DSN in formats and on schedules defined in the MaRS Archive Generation, Validation, and Transfer Plan [REF1]. In general, delivery to the MaRS PI will be as soon as the volumes have been validated (e.g., 1-2 weeks after data acquisition). Based on data volume and rate predictions in the "Data Acquisition" section above, an average of 3 GB of raw data (approximately 5 CD's or one DVD) will be collected and delivered each week. The table below shows data types expected to be included in the raw data archive. Formats are ASCII, binary, and ASCII extract (AX) from a binary original. File names, data set ID, volume ID, and other nomenclature issues have either been addressed in [REF1] or will be negotiated with the MaRS PI. All data products will be accompanied by PDS labels and will comply with PDS standards [REF3, REF4]. The MaRS PI will integrate the Stanford contributions with other data and submit the full package to the ESA PSA. |==================================================| | Data Type |Source|Format(s)| |=================================+======+=========| |Radio Science Receiver (RSR) | QS-R | binary | |---------------------------------+------+---------| |RSR Browse plots (BRO) | SUE | binary | |---------------------------------+------+---------| |Tracking and Navigation (TNF) | QS-T | binary | |---------------------------------+------+---------| |Orbit Data File (ODF) |OSCARX| binary | |---------------------------------+------+---------| |DSN Monitor Data (MCH) | QS-M | binary | |---------------------------------+------+---------| |Monitor Channel Tables (MCT) | SUE | AX | |---------------------------------+------+---------| |Ionosphere Calibration (ION) |OSCARX| ASCII | |---------------------------------+------+---------| |Troposphere Calibration (TRO) |OSCARX| ASCII | |---------------------------------+------+---------| |DSN Meteorology Data (WEA) |OSCARX| ASCII | |---------------------------------+------+---------| |Earth Orientation (EOP) | EIS | ASCII | |---------------------------------+------+---------| |Spacecraft Engineering (ECH) | ESOC | AX | |---------------------------------+------+---------| |Lighttime Files (LIT) | MDOM | ASCII | |---------------------------------+------+---------| |Sequence of Events Files (SOE) | MDOM | ASCII | |---------------------------------+------+---------| |DSN Keyword Files (DKF) | MDOM | ASCII | |---------------------------------+------+---------| |Orbit Propagation/Time (OPT) | MDOM | ASCII | |---------------------------------+------+---------| |S-P Kernels (BSP) | NAIF | binary | |---------------------------------+------+---------| |Spacecraft Attitude (BCK) | NAIF | binary | |---------------------------------+------+---------| |Spacecraft Clock (SCK) | NAIF | ASCII | |---------------------------------+------+---------| |Frame Kernel (FRK) | NAIF | ASCII | |---------------------------------+------+---------| |Planetary Constants (PCK) | NAIF | ASCII | |---------------------------------+------+---------| |Leap Second (LSK) | NAIF | ASCII | |---------------------------------+------+---------| |Network Monitor/Control (NMC) | DSN | ASCII | |---------------------------------+------+---------| |Experimenter Notebook (ENB) | SUE | ASCII | |---------------------------------+------+---------| |Daily Health Report (HEA) | SUE | ASCII | |---------------------------------+------+---------| |Surface Reflection Geometry (SRG)| SUE | ASCII | |---------------------------------+------+---------| |Manifest - list of files (MFT) | SUE | ASCII | |==================================================| In addition, the MaRS PI has requested that we provide files meeting different naming and aggregation criteria, which will more easily fit into the archiving system being developed at his home institution. This additional work is in progress. 5.2 Calibrated Data Archive The following data products have been identified for the Calibrated Data Archive. All products will be generated in the form of ASCII tables and will meet PDS standards [REF3, REF4]. Calibrated data will be delivered to the MaRS PI within two months of the corresponding data acquisition. The MaRS PI will integrate the Stanford contributions with other data and submit the full package to the ESA PSA. |===========================================================================| | Data Type | Source |Typical Data Rate| |=================================+=======================+=================| |Frequency and amplitude estimates|POWERFIT from | 0.1 MB/week | | vs time (f~, A~) |occultation analysis | | |---------------------------------+-----------------------+-----------------| |Calibrated Average Power Spectra |Modified LOOK step in | 0.1 MB/week | |(APS'); cross-spectra |Quick-Look processing | | |===========================================================================| 5.3 Reduced Data Archive The following data products have been identified for the Reduced Data Archive. All products will be generated in the form of ASCII tables and will meet PDS standards [REF3, REF4]. They will be delivered to the MaRS PI within two months of the corresponding data acquisition. |===========================================================================| | Data Type | Source |Typical Data Rate| |=================================+=======================+=================| |Temperature-pressure profiles vs |Abel inversion, gas law| 0.1 MB/week | | radius: T-p(r) |and hydrostatic equilib| | |---------------------------------+-----------------------+-----------------| |Electron density profiles vs |Abel inversion; Yeh and| <0.1 MB/week | | radius: e(r) |Liu conversion | | |---------------------------------+-----------------------+-----------------| |Reflectivity and dielectric |Arithmetic operations | <0.1 MB/week | |constant vs latitude-longitude |on calibrated data | | |===========================================================================| 6 Roles and Responsibilities 6.1 G.L. Tyler (SUE PI) G.L. Tyler will serve as leader of the Stanford group of investigators. During Phase E he will work with MaRS PI Paetzold, Hinson, and Simpson in detailed operations planning and execution of the MaRS atmospheric occultation and surface scattering investigations. He will oversee the data processing and analysis at Stanford, and collaborate on the interpretation of results from both types of investigations. 6.2 D.P. Hinson (Radio Occultations) D.P. Hinson has the lead responsibility for investigation of the atmosphere by radio occultation sounding. He will work with Tyler, Simpson, and Paetzold in operational implementation and execution of observations, and with the MaRS Team in interpretation and publication of the results. He will carry responsibility for production of occultation derived soundings of the atmosphere and ionosphere, including both calibrated and reduced data as defined above. 6.3 R.A. Simpson (Surface Scattering and Data Management) R.A. Simpson has lead responsibility for investigations of the martian surface by means of oblique (bistatic) surface scattering observations. He will work with Tyler, Hinson, and Paetzold in planning and carrying out observations, and with the MaRS Team in interpretation and publication of the results. He will carry primary responsibility for producing measures of surface parameters based on scattering results, including both calibrated and reduced data as defined above. Simpson will also assume primary responsibility for data organization and management at Stanford, including collection of New Norcia data (when those become available) from ESA sources and preparation of archival data records which will eventually, by way of the ESA Planetary Science Archive, be deposited with the NASA Planetary Data System. 6.4 Other Personnel Hinson and Simpson will be assisted by a part-time scientific programmer and one or more part-time graduate students. The scientific programmer is currently identified as J.D. Twicken. 7 Facilities and Institutional Support Members of the SUE work in the Space, Telecommunications, and Radioscience Laboratory (STARLab) of the Department of Electrical Engineering at Stanford University. STARLab is housed in the Packard Electrical Engineering Building which has state-of-the art networking (multiple 100 Mbs to all rooms, 1 Gbs optional). The facilities supporting Mars Express will be a central work station and file server, a color laser printer, a Science Operation Planning Computer (SOPC), a CD copier, and several desktop satellite work stations. There are also several desktop PC-type machines with peripherals such as scanners available for word processing, spreadsheet development, and presentations. All computers are networked; the SOPC is connected to JPL via a 56 kbs data line and it is protected from the Stanford network by a Cisco router. Most of this equipment is maintained in a secure room (approximately 600 sq ft) with access limited to approved individuals. Most of the equipment listed above has been acquired to support Mars Global Surveyor. It has been used by other projects such as Mars Express and the Planetary Data System on a non-interference time-available basis. We expect that sharing arrangement to continue except that Mars Express will now begin providing the core components. The Sun Blade 2000 was recently obtained with funding budgeted for Mars Express Phase C/D; it replaces an MGS Sun Ultra Enterprise 2. Several of the satellite workstations are scheduled for upgrade using Phase E funds early in FY04. We expect to add a DVD writer in FY05, as the volume of bistatic radar (RSR) data begins to increase. The MaRS SUE processing configuration is shown in the diagram below. The 1 TB disk system is sized to hold a few months of data; files will be processed, then off-loaded to tape and CD-R (later, DVD-R). For Mars Express, the RSR volume from bistatic radar experiments will be largest. Although storing all of the raw data on line would require a nominal 0.3 TB, the first two stages of processing (PREPRSR and EQUALIZE) will generate 2.4 TB of output; so not all data can be maintained on-line in raw, intermediate, and final forms for the length of the mission. MGS, which will be using the new Sun Blade 2000 on a non-interference basis, will also have storage requirements. ------ ------ | DELL | | DVD-R| |----| PC |----|WRITER| | ------ ------ | ------- ------ | ----- | 72 GB | | CD | | | 1 TB | | DISK | |WRITER| | | DISK | ------- ------ | ------ -------- | | | | --| TAPE 0 | ------- | | ------- | -------- 56 kbs | SUN |----- | | SUN |--- -------- to/fm -->|ULTRA 5| -------- |----| BLADE |------| TAPE 1 | JPL | SOPC |---| ROUTER |---| | 2000 | -------- ------- -------- | ------- | | ----------- | --------- | HP 4000N | | | COLOR | | B&W | |---| LASER | | PRINTER | | | PRINTER | ----------- | --------- | -------- -------- ----------- ---- | | HINSON | | SIMPSON| | MACINTOSH | | PC | | |COMPUTER| |COMPUTER| ----------- ---- | -------- -------- | | | | | <----------------------------------------------------------> Packard Building Net | other | users | Stanford Net V to/from MaRS 8 References Fjeldbo, G., A.J. Kliore, and V.R. Eshleman, The neutral atmosphere of Venus as studied with the Mariner V radio occultation experiments, Astronomical Journal, 76, 123-140, 1971. Simpson, R.A., and G.L. Tyler, Mars Global Surveyor bistatic radar probing of the MPL/DS2 target area, Icarus, 152, 70-74, 2001. Tyler, G.L., G. Balmino, D.P. Hinson, W.L. Sjogren, D.E. Smith, R. Woo, S.W. Asmar, M.J. Connally, C.L. Hamilton, and R.A. Simpson, Radio science investigations with Mars Observer, Journal of Geophysical Research, 97, 7759- 7779, 1992. Yeh, K.C., and C.H. Liu, Theory of Ionospheric Waves, San Diego: Academic Press, 464 pp., 1972.