----+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
INTCOM 890601. 890701.
----+----0----+----0----+----0----+----0----+----0----+----0----+----0----+----0
COLUMNS FORMAT DESCRIPTION DEFAULT VALUE & UNITS
1-6 A6 INTCOM: Turns on the intercomparison
capability. This option allows the user
to perform certain specific orbit
generation runs. In these runs some
assumptions are made, or certain
perturbations only are turned on in
order to study the output orbit and/or
compare it with orbits generated by
similar software packages.
The output orbit is writen on unit59 at
a rate depending on the users request on
the ORBTVU card and expressed in inertial
True-of-Date Cartesian elements. [NOTE 2]
The assumptions and/or supressions for
each individual case are described under
Case Indicator on columns 9-10.
9-10 I2 Case Indicator: Integer number which indicates
a specific case. See NOTE 1 for description of
the individual cases.
25-44 D20.8 Start time for 3-hourly kp values storage Epoch start
in the form YYMMDD. (Applies on Case 15) time
45-59 D15.8 Stop time for 3-hourly kp values storage in Epoch stop
the form YYMMDD. (Applies on Case 15) time
JUNE 1991
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GLOBAL SET
INTCOM (cont)
NOTE [1]: 1 Two body orbit generation (point masses) - Output mean of reference
system - Supressed precession and nutation - No other forces
applied. (CASE1A of the TOPEX intercomparison)
2 Two body - Output True-of-Date - Only precession and nutation
applied. - No other forces applied.(CASE1B of the TOPEX
intercomparison)
3 Two body - Output Pseudo body-fixed - Fixed true pole - Tests
Greenwich hour angle and UT1 - Modify POLE cards accordingly.
(CASE1C of the TOPEX intercomparison)
4 Two body - Output body fixed - UT1=UTC - Tests polar motion -
corrections will be applied to UT1-UTC - Modify POLE cards
accordingly. (CASE1D of the TOPEX intercoimparison).
5 Two body - Output full body-fixed - Tests polar motion and UT1
combined. (CASE1E of the TOPEX intercomparison).
6 Case 2 - application of J2 (CASE2 of the TOPEX intercomparison).
7 Case 2 + Point mass effects for other celestial bodies - Modify
PLANET cards accordingly. (CASE3A of the TOPEX intercomparison).
8 Case 7 + Indirect effect of the Earth's J2. (CASE3B of the
TOPEX intercomparison).
9 Case 6 + Polar motion and UT1 (CASE4 of the TOPEX intercomparison).
10 Case 6 + Complete gravity model GEM-T1.
Tests Gravity Model. (CASE5 of the TOPEX intercomparison).
11 Case 6 + Empirical along track accelerations - Include necessary
ACCEL cards. (CASE6 of the TOPEX intercomparison).
12 Case 6 + Solar radiation - Use SOLRAD card. (CASE7 of the TOPEX
intercomparison).
JUNE 1991
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INTCOM (cont)
NOTE [1]: (cont)
13 Case 10 + Simple solid Earth tide model - Use correct input
on the TIDES cards (CASE8 of the TOPEX intercomparison).
14 Case 10 + Complete Earth and Ocean tides. (CASE9 of the TOPEX
intercomparison).
15 Case 6 + Drag application using DTM atmospheric model -
Constant fluxes are used - FLUX and ATMDEN cards are necessary.
Three hourly Kp values are used - Include the right BIH tables
on UNIT02. (CASE10 of the TOPEX intercomparison).
16 All perturbations in Cases 2-15 applied. (CASE11 of the TOPEX
intercomparison).
17 Case 6 + Earth radiation - Use ALBEDO card AND SOLRAD card.
(CASE12 of the TOPEX intercomparison).
18 Case 6 + General relativity - Use REL300 card. (CASE13 of the
TOPEX intercomparison).
NOTE [2]: OUTPUT FORMAT
A. HEADER RECORD
ITEM FORMAT DESCRIPTION
1-132 A1 Description of the run. Contents of the second
COMMON TITLE card.
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GLOBAL SET
INTCOM (cont)
NOTE [2]: (cont)
B. EPHEMERIS RECORDS (Two records for each point)
First record
ITEM FORMAT DESCRIPTION
1 D22.16 Julian Date (integral part) (UTC)
2 D22.16 Fractional Julian Date (UTC)
3 D22.16 Greenwich Hour Angle
4-6 3D22.16 Satellite X Y Z elements (meters)
Second record
1-3 3D22.16 Satellite Xdot Ydot Zdot elements (meters/sec)
4 D22.16 Satellite geodetic latitude
(instantaneous z axis) (degrees).
5 D22.16 Satellite East longitude (degrees).
6 D22.16 Satellite height above the reference ellipsoid
(meters).
NOTE [3]: Sample UNIT05 setups for the orbit generation
options exist in ZCDEP.TOPEX.UNIT05.DATA. The
GLOBAL TITLE cards describe the individual cases.
IF CARD IS OMITTED: No Intercomparison will take place.
JUN 1987
8704.0
GLOBAL SET