InitialState

Import initial state data to a vehicle or export initial state data to a file

Syntax

InitialState <ObjectPath> {Import | Export} {Source} ["<FilePath>"] [{Options}]

Description

The InitialState Connect command allows you to import a previously created STK Satellite, STK Ephemeris, IIRV, Type 9 IIRV, EPV file or NASA Flight Dynamics Facility IIRV file containing initial state data for a satellite or missile.

With this command you can also export initial state data from a satellite or missile as a IIRV, IIRV Type9, EPV file or NASA Flight Dynamics Facility IIRV.

The format used will depend on the whether Import or Export is specified. Formats are outlined below.

Generic Parameters

Valid values for {Source} are described in the table below.

The "<FilePath>" parameter includes the full path and name of the file to be imported or exported.

Note: The "<FilePath>" parameter is required for both Import and Export unless the {Source} is STKEphem.

Import Options

A Satellite must be using one of the following propagators: TwoBody, J2Perturbation, J4Perturbation, HPOP, LOP or Astrogator. If the Satellite has not been propagated then the propagator will be set to HPOP.

A Missile must be using the TwoBody or HPOP propagator. If the Missile has not been propagated then the propagator will be set to HPOP.

The ephemeris step size for the Satellite or Missile will be set to 60.0 seconds, unless the propagator is LOP, in which case the step size will be set to 1 day.

Note: HPOP must propagate from the orbit epoch to the start time, so use caution when selecting a satellite or ephemeris file. (i.e. check the epoch time in the file)

The following table describes the Import {Options}.

Import Deprecated Format

The format for the InitialState Import options was changed in STK 9. The following describes the format in previous versions of STK. This format should no longer be used but is included for backward compatibility.

InitialState <ObjectPath> Import {Source} "<FilePath>" [{EpochSelect} "<TgtEpoch>" <InterpOrder>]

Export Options

If you are exporting an initial state file, valid command format is:

InitialState <ObjectPath> Export {Source} "<FilePath>" {CrdnSystem} [{ExportOption} <Value> [{ExportOption} <Value>...]]

If you are exporting an initial state file, valid values for {CrdnSystem} will depend on the {Source} specified.

If {Source} is IIRV, valid {ExportOption} <Value> combinations are:

If {Source} is IIRV1, valid {ExportOption} <Value> combinations are:

If {Source} is IIRV9, valid {ExportOption} <Value> combinations are:

If {Source} is EPV, valid {ExportOption} <Value> combinations are:

If {Source} is NASAIIRV, valid {ExportOption} <Value> combinations are:

Example

Propagate Satellite2 using an external EPV file:

InitialState */Satellite/Satellite2 Import EPV "c:\stkdb\epvC1.epv"

To propagate Satellite2 using the iirvIPC3.iirv file:

InitialState */Satellite/Satellite2 Import IIRV "C:\stkdb\iirvIPC3.iirv"

Propagate TestSat2 using the last ephemeris point from the file Satellite1.e:

InitialState */Satellite/TestSat2 Import STKFile "C:\STKUser\TestScen\Satellite1.e" EpochSelect LastPoint

The following series of commands will create a satellite with Astrogator propagator and set the Initial State for the satellite:

New / */Satellite AstroSat2

Astrogator */Satellite/AstroSat2 SetProp

InitialState */Satellite/AstroSat2 Import STKFile "C:\STKUser\Satellite2.e" GatorPath "MainSEQUENCE.SegmentList.Initial_State"

Use the closest data point, in the file Satellite1.e, following the Epoch to set the initial state:

InitialState */Satellite/TestSat2 Import STKFile "C:\STKUser\TestScen\Satellite1.e" Epoch "1 Jul 2006 14:00:00.00" EpochSelect ClosestFollowing

Use the closest data point to the Epoch, from the ephemeris of TestSat1, to set the initial state:

InitialState */Satellite/TestSat1 Import STKEphem EpochSelect ClosestPoint Epoch "Scenario/FieldTestSc AnalysisStartTime"

Example

Create an IIRV T9 file from Satellite SunSync, with an SRP of 1.234 and a defined start and stop time:

InitialState */Satellite/SunSync Export IIRV9 "c:\stkdb\iirvIPC1.iirv9" GeocentricTODRotating SRP 1.234 UseStartStop "1 Jun 2002 12:00:00.00" "1 Jun 2002 18:00:00.00"

Create an IIRV file from Satellite Sat1, setting various parameters:

InitialState */Satellite/Sat1 Export IIRV "c:\stkdb\iirvIPC2.iirv" GeocentricTODRotating Destination SAE1 VectorType Cutoff VectorSource realtime SupportID 678 VehicleID 34 CounterStart 765

Create an IIRV T1 file from Missile Missile1:

InitialState */Missile/Missile1 Export IIRV1 "C:\Temp\InitialState\Missile1.iirv1" GeocentricTODRotating Drag 1.234 UseStartStop "1 Jul 2006 12:00:00.000" "1 Jul 2006 12:20:00.000"

Export an initial state file in NASA IIRV format, the following file will be created, ephmTc12009143:

InitialState */Satellite/Satellite1 Export NASAIIRV "C:\STKUser\IIRVFiles" GeocentricTODRotating MissionID Tc1

Export an initial state file in EPV format:

InitialState */Satellite/Satellite2 Export EPV "C:\STKUser\IIRVFiles\epvIPC1.epv" TODJ2000 MessageID 123 MessageOrigin KMR VehicleID 34 UseStartStop "Satellite/Satellite1 EphemerisTimeSpan Interval" SupportID 56

ReturnMessage

If activated, Connect returns an acknowledgement message.

Group Membership

This command belongs to the following group(s):

Vehicles

Version

10

STK Programming Interface 11.0.1