TSAC media calibrations conform to the Command Statement Processor (CSP) English-like command language used by the Orbit Determination Program (ODP) to adjust, delete, or weight data points. The language is described in detail in the DPTRAJ-ODP User's Reference Manual (618-783 Rev. B, Vol. 1, Section 36).
In general, a CSP command consists of a verb and optional scope limiters and computation specifiers, terminated by a period. A command may, and frequently does, extend over more than one card image. The CSP commands produced by the TSAC software comprise a small subset of those used by the ODP. Elements of CSP commands used in the TSAC media calibrations are given in Table TRK-2-23-1; examples of the calibrations are given below under the subheadings Tropospheric Calibrations, Ionospheric Calibrations, and Solar Plasma Calibrations. tropospheric, ionospheric.
Table TRK-2-23-1. CSP Elements Used in TSAC Media Calibrations +-------------------------------------------------------------------------+ | Type of Element | Elements Used | | | | |-------------------------|-----------------------------------------------| | Verbs | ADJUST, DELETE | | | | | Scope Limiters | Time Span Limiters: | | | FROM BEFORE | | | TO AFTER | | | AT | | | | | | Network (Complex or Station): | | | DSN | | | C10 11, 12, 13, 14 | | | C40 42, 43, 44 | | | C60 61, 62, 63 | | | | | | Band: X, X; L (VAX ODP only) | | | | | | Source: SCID, QUASAR | | | | | Computation Specifier | Series Type: | | | BY NRMPOW BY DNRMPOW | | | BY CONST BY DCONST | | | BY TRIG BY DTRIG | | | Model: | | | DRY NUPART (dry troposphere) | | | WET NUPART (tropospheric water vapor) | | | CHPART (ionosphere) | | | DRVID (ionosphere + solar plasma) | | | | | | Data Type: | | | DOPPLER F1, F2, F3, F3C | | | RANGE PLOP | | | VLBI | | | DVLBI | +-------------------------------------------------------------------------+The year, month, day, hour, and minute values are integers; seconds are double precision. Up to three of the right-most time fields may be omitted. When omitted, their values are taken to be zeros. The calibrations apply only during the times specified by the time-span limiter(s). If the limiter is AT, the time span depends on the computer word length. On the UNIVAC (36-bit word length), the time span is from one microsecond before the given time to one microsecond after; on the VAX (32-bit word length), it is from one millisecond before to one millisecond after.
If the ADJUST command contains BY NRMPOW (CO, C1, ...,
CN) FROM (S) TO (E), where S and E refer to the start and end
times for the command, the calibration is computed from the
normalized power series CO + C1 * X + C2 * X2 + ... + CN * XN.
This polynomial is called "normalized" because the time argument
of the series, T, has been replaced by the normalized,
dimensionless argument X, which is defined to be -1 when T = S
and +1 when T = E. This normalization is done by a change of
variable given by
X = 2*( (T-S)/(E-S) ) - 1.
Up to 24 single-precision or 12 double-precision coefficients are
allowed in one series.If the ADJUST command contains BY CONST (C), the calibration is given by the constant C.
If the ADJUST command contains BY TRIG (P, AO, A1, B1, A2, B2, ..., AN, BN) AFTER (S), the calibration is given by the Fourier series
AO + A1 cos x + B1 sin x + A2 cos 2x + B2 sin 2X + ...
+ AN cos Nx + BN sin Nx,
where x = 2 * PI * (T - S)/P; P is the period of the fundamental mode,
in seconds.
An example of the format for tropospheric calibrations is given in Figure TRK-2-23-1 of this module.
Figure TRK-2-23-1. Format for Tropospheric Calibrations ADJUST (ALL) BY NRMPOW (.5385215940876400-001,-.1545263252791661+000, .6120410421392178+000,.8393903860788785+000,-.1757061589993537+001, -.1192449606993796+001,.1774783212089319+001,.6265889342013949+000, -.7481685636314813+000,-.1116904190364361+000,.1136781820255777+000) MODEL (WET NUPART) FROM (83/1/1,00:00:00.01) TO (85/1/1) DSN (C10).
The Magnitude of the vertical ionospheric range delay at each complex depends on time of day, season, and time since start of the current solar cycle; it can range from less than 1 meter to more than 8 meters. Because the slant-range adjustment factor can vary from unity at zenith to about 3.5 at 0 degrees elevation, the resulting total variation in line-of-sight ionospheric calibration can range from less than 1 meter to more than 25 meters.
The time spans of each polynomial, except in special circumstances, are from spacecraft rise (0 deg) to spacecraft set (0 deg) at the station or complex.
An example of the format for ionospheric calibrations
is given in figure TRK-2-23-2.
Figure TRK-2-23-2. Format for Ionospheric Calibrations ADJUST (ALL) BY NRMPOW (.127504448000000D+001,-.363046489000000D+000, .221433675000000D+001,.385002747000000D+000,-.476505244000000D-001, -.379998393000000D+000) MODEL (CHPART) FROM (84/10/31,20:40:55) TO (84/11/1, 10:45:30) DSN (C40). #S/C32 PRED S66 841011
An example of the format for solar plasma calibrations
is given in Figure TRK-2-23-3.
Figure TRK-2-23-3. Format for Solar Plasma Calibrations
ADJUST (F2) BY CONST (.3875553049-001) AT
(84/10/1,00:03:30) DSN(43) BAND (S).
ADJUST(FLOP) BY CONST (.6939884663+002) AT
(84/10/1,00:19:46) DSN(43) BAND (S).
ADJUST (F2) BY CONST (.3650530707-001) AT
(84/10/1,00:20:30) DSN(43) BAND (S).
ADJUST (F2) BY CONST (.2018998959-001) AT
(84/10/1,00:36:30) DSN(43) BAND (S).
ADJUST(PLOP) BY CONST (.5467516279-002) AT
(84/10/1,00:38:03) DSN(43) BAND (S).
ADJUST (F2) BY CONST (-.5899344711-001) AT
(84/10/1,00:47:30) DSN(43) BAND (S).
ADJUST (F2) BY CONST (.-5087723862-001) AT
(84/10/1,00:54:30) DSN(43) BAND (S).
ADJUST(FLOP) BY CONST (.6912411022+002) AT
(84/10/1,00:56:20) DSN(43) BAND (S).
ADJUST (F2) BY CONST (-.7026034500-001) AT
(84/10/1,01:01:30) DSN(43) BAND (S).
Revision date: 27 November 1995
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