TrackingFileSet

TrackingFileSet

TrackingFileSet — Manages the observation data contained in one or more external tracking data files.

Description

A TrackingFileSet is required for both simulator and estimator runs. For a data simulation run, the user must specify the desired tracking strings for the simulated data (via AddTrackingConfig) and provide an output file name for the simulated tracking observations (via FileName). In simulation mode, the user may specify a range modulo constant, Doppler count interval, and other parameters, depending on the type of tracking data being simulated. See the remarks below for more details.

When running the estimator, the FileName parameter specifies the path to a pregenerated external tracking data file. It is not necessary to explicitly specify tracking configurations when running the estimator; GMAT will examine the specified external tracking data file and determine the tracking configurations automatically. GMAT will throw an error message if it is unable to uniquely identify all objects found in the tracking data file.

When running the estimator, one or more AcceptFilters and/or RejectFilters may be employed to select from all available observations a smaller subset for use in the estimation process.

The SimRangeModuloConstant and SimDopplerCountInterval fields apply only to the simulator and are ignored by the estimator. When running the estimator, these values are provided in the tracking data file. For both the simulator and estimator, relativity, light time, and ET-TAI corrections may optionally be applied.

See Also: Simulator, BatchEstimatorInv, AcceptFilter, RejectFilter, Tracking Data Types for OD

Fields

Remarks

See Tracking Data Types for OD for a detailed listing of all tracking data types and tracking data file formats supported by GMAT for orbit determination.

Setting UseETminusTAI to True corresponds to inclusion in the computed round-trip light time of the ET-TAI uplink and downlink terms in Eq. 11-7 of Moyer, Formulation of Observed and Computed Values of Deep Space Network Data Types for Navigation, JPL Publication 00-7, October 2000. Setting UseRelativityCorrection to True corresponds to inclusion of the RLT uplink and downlink terms in Eq. 11-7 of Moyer.

The SimRangeModuloConstant field is used only in the simulation of DSN range tracking data. The user may specify a value to be used for this field or may omit it, in which case the default value is used. This field is not applicable to estimation. In estimation, this value is provided in the input tracking data file.

The SimDopplerCountInterval is used in the simulation of DSN_TCP and RangeRate tracking data. The user may specify a value to be used for this field or may omit it, in which case default value of 1 second is used. This field is not applicable to estimation. In estimation, this value is provided in the input tracking data file.

When displaying or saving a TrackingFileSet object using the Write command, GMAT will display a number of items relevant to simulating TDRS data formats. These options are not implemented in the current release and should be ignored or manually removed from the output file.

Examples

Create TrackingFileSet dsnObs;

%Create objects referenced by dnsObs
Create GroundStation GDS CAN MAD;
Create Spacecraft EstSat;
Create AcceptFilter af;
  
dsnObs.AddTrackingConfig       = {{GDS, EstSat, GDS}, 'DSN_TCP'};
dsnObs.AddTrackingConfig       = {{CAN, EstSat, CAN}, 'DSN_TCP'};
dsnObs.AddTrackingConfig       = {{MAD, EstSat, MAD}, 'DSN_TCP', 'DSN_SeqRange'};
dsnObs.FileName                = {'dsn.gmd'};
dsnObs.RampTable               = {'dsn.ramp'};
dsnObs.UseLightTime            = True;
dsnObs.UseRelativityCorrection = False;
dsnObs.UseETminusTAI           = False;
dsnObs.SimRangeModuloConstant  = 67108864;
dsnObs.SimDopplerCountInterval = 10.; 
dsnObs.DataFilters             = {af};

BeginMissionSequence;

Create TrackingFileSet PosVecObs;

PosVecObs.FileName          = {'posvec_obs.gmd'};
PosVecObs.AddTrackingConfig = {{SimSat.GpsReceiver}, 'GPS_PosVec'};
SimMeas.DataFilters         = {};

BeginMissionSequence;