SetPosition (Vehicles)
Set the position of a vehicle
Syntax
SetPosition <ObjectPath> {PositionType} {TimeValue} <PositionData>
Related commands
Description
The SetPosition command allows you to create ephemeris data for a vehicle by sending it, point by point, to STK. This is especially useful if you wish to determine a vehicle's position using real-time data.
You can't use the SetPosition command to modify a vehicle's propagated ephemeris. This command can only be used to append ephemeris points to a vehicle.
For valid {TimeValue} values see Time Options.
{PositionType} and <PositionData> can be:
| {PositionType} | <PositionData> | Description |
|---|---|---|
| B1950 | <x> <y> <z> [<vx> <vy> <vz>] | The input values are in the B1950 coordinate frame. |
| ECF | <x> <y> <z> [<vx> <vy> <vz>] | Origin is at the center of the Earth and axes which are fixed to the Earth. |
| ECI | <x> <y> <z> [<vx> <vy> <vz>] | Origin is at the center of the Earth and axes which are fixed in inertial space. The inertial coordinate system is J2000. |
| LLAHPS | <Lat> <Lon> <Alt> <Heading> <Pitch> <Speed> | <Lat> and <Lon> are entered in Connect Latitude and Longitude units (default is degrees). <Alt> is entered in Connect Distance units. Enter <Heading> and <Pitch> in degrees. Enter <Speed> in Connect units (Distance/Time).
<Heading> is entered as degrees from North and is the rotation about the Z-axis; <Pitch> is the rotation about the Y-axis. |
| LLA | <Lat> <Lon> <Alt> [<LatRate> <LonRate> <AltRate>] | The LLA {PositionType} measures <Alt> from the surface of the Earth, or 0. The AGL_LLA {PositionType} considers terrain at the specified location when measuring <Alt>. The MSL_LLA {PositionType} considers mean sea level at the specified location when measuring <Alt>. <LatRate> and <LonRate> are entered in degrees. <Lat> and <Lon> are entered in Connect Latitude and Longitude units (default is degrees). |
| AGL_LLA | ||
| MSL_LLA | ||
| Reference | <x> <y> <z> [<vx> <vy> <vz>] | Cartesian position data is interpreted relative to current ephemeris reference system, default is ECF, but it can be changed using the SetPosition DataReference command. |
| "<TruncObjectPath> <CrdnName>" | <x> <y> <z> [<vx> <vy> <vz>] | Explicitly specify reference coordinate system relative to which Cartesian position data is interpreted.
<TruncObjectPath> is the truncated path of the parent object followed by a space and the <CrdnName>, all in quotes. For example: "Satellite/attSat Body", specifies the Body system of attSat. If specifying the Crdn of a central body, include the truncated path of the central body followed by a space and the <CrdnName>, all in quotes. For example: "CentralBody/Earth Inertial". |
| UTM | <ZoneStr> <Easting> <Northing> <Alt> [<LonRate> <LatRate> <AltRate>] | Valid values for <ZoneStr> are A, B, Y, Z or ddc, where 00<dd<61 and c is C-X. <Easting>, <Northing> and <Alt> are entered in Connect distance units. <LonRate> and <LatRate> are entered in degrees/second. <AltRate> is entered in COnnect distance units/second. |
Velocity and Rate values are optional where indicated, for most {PositionType}.
For more information on Central Body Coordinate Systems, see "Technical Notes for Central Bodies".
If this command is used for a new vehicle with no prior path definition, the input ephemeris is saved to an external ephemeris file when the vehicle is saved.
Examples
To add one ephemeris point to the Aircraft Cessna using the latitude/longitude/altitude coordinate system:
To add one ephemeris point to the satellite Shuttle in the current scenario using the latitude/longitude/altitude coordinate system:
To add one ephemeris point to Satellite1 using the coordinate system set with the SetPosition DataReference command:
To add one ephemeris point to Satellite1 using a coordinate system defined in the Vector Geometry Tool:
Return message
Group membership
This command belongs to the following group(s):
Version
10