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TDRS User Range and Doppler minor and cosmetic bugs



  • SN Doppler processing seems to require me to set the user (Aqua) transponder turn-around ratio to ‘1:1’ and the TDRS transponder ratio to ‘1:1’ for things to look good. I expected to set the Aqua turnaround ratio to ‘240:221’, but that makes the Doppler look bad.

  • Rename TrackingFileSet.SimTDRSDataFlag to SimTDRSTrackerType. This name better matches the name given in the UTDF spec for this parameter.

  • Rename TrackingFileSet.SimTDRSNode4Frequency to SimTDRSNominalUserTransmitFrequency.

  • Set a default value for TrackingFileSet.SimTDRSServiceAccessList

  • Not sure if GTDS applies any iono correction for TDRS user data. Obs and residuals look the same with and without iono on. Need to check with Mark on this.

    • See SES script /home/sslojkow/gmat/tdrsuser/aqua_elem_gtds.dc

  • (For SES) Remove TEST mode flag from all existing TDRS data test cases.

    • Review deferred test list and un-defer any TDRS test cases

  • Setting MaxCentralAngleOfRayPath to a wide-open value (180 degrees) causes GMAT to ignore the central body occultation check. This check should always be performed.

  • MaxCentralAngleOfRayPath should allow the values of 0 and 180.

  • Estimation of ThrustScaleFactor does not work with TDRS data. An error message appears ODEModel Exception Thrown: Multiple Spacecraft are not allowed in a propagator driving a finite burn; try breaking commands of the form "Propagate prop(sat1, sat2)" that execute with a finite burn on one of the spacecraft into two synchronized propagators; e.g. "Propagate Synchronized prop(sat1) prop(sat2)"

    • See test case ThrustSegment_SolveFors_ThrustScaleFactor_SN

  • Estimation of N-Plate area coefficient does not work with TDRS data. An error message appears GmatBase Exception Thrown: GmatBase::GetParameterID() The object named "EstPlate1" of type "Plate" has no parameter defined with "StmElementNames"

    • See test case Plate_SolveFors_AreaCoefficient_SN

  • Errors due to transponder delay modeling are slightly larger than expected, in approximately the 10 or 11 significant digit. This is probably OK, but want concurrence from the team

    • See test case Transponder_HardwareDelay_Sim_SnRange




Steve Cooley


Steven Slojkowski


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