Set the orbit state of a satellite or missile using equinoctial coordinates
SetState <VehObjectPath> Equi {Propagator} {NoProp | {TimeInterval}} <StepSize> {CoordSystem} "<OrbitEpoch>" <SemimajorAxis> <h> <k> <p> <q> <MeanLon> {Retrograde | Posigrade} ["<CoordEpoch>"]
The SetState Equi command sets the orbit state of the specified satellite or missile and propagates the orbit over the specified time period. The propagated ephemeris data is spaced by the <StepSize> parameter.
Note: The SetState Equi command is valid for Satellite and Missile only.
| Parameter | Description |
|---|---|
| {Propagator} | This parameter is case sensitive and
the Propagator name must match the format used in the Satellite's
Orbit page or Missile's Trajectory page under Basic properties.
Valid values for Satellite are TwoBody, J2Perturbation, J4Perturbation, HPOP and LOP. Valid values for Missile are TwoBody and HPOP. |
| {NoProp | {TimeInterval}} |
Enter NoProp to set the state of the vehicle but not propagate it. Enter {TimeInterval} to define the beginning and end of the satellite's time period for propagation. For valid {TimeInterval} values see Time Options. |
| <StepSize> | Entered in seconds and must be greater
or equal to 0.001 seconds.
Note: If LOP propagator is selected, the <StepSize> must be greater or equal to one day (86164.09 seconds). |
| {CoordSystem} | This parameter is case sensitive and the CoordSystem name must match the format used in the Orbit page of the satellite's Basic properties. Valid Values are ICRF, J2000, MeanOfDate, MeanOfEpoch, TrueOfDate, TrueOfEpoch, B1950, TEMEOfDate, TEMEOfEpoch, AlignmentAtEpoch. |
| "<OrbitEpoch>" | For valid "<OrbitEpoch>" values see Time Options. |
| <SemiMajorAxis> | Entered in Connect distance units. |
| <h> | A real number between -1.0 and 1.0 |
| <k> | A real number between -1.0 and 1.0 |
| <p> | A real number between -1.0 and 1.0 |
| <q> | A real number between -1.0 and 1.0 |
| <MeanLon> | Entered in degrees. |
| {Retrograde | Posigrade} | Enter orbit direction. |
| ["<CoordEpoch>"] | This parameter is only applicable, and
is required, for {CoordSystem} based on an Epoch, such as
MeanOfEpoch, TrueOfEpoch, TEMEOfEpoch and AlignmentAtEpoch.
For valid "<CoordEpoch>" values see Time Options. |
Propagator-specific parameters stored with the vehicle instance aren't affected. For example, when the SetState Equi command is received and an HPOP {Propagator} is specified, the existing HPOP force model data is used. If you create a vehicle and modify the force model, or load a vehicle with a modified force model, that data isn't modified by this command. If a new vehicle is created using the New command, the default force model data is used.
<h> and <k> collectively describe the shape of the vehicle's orbit and the position of perigee while <p> and <q> collectively describe the orientation of the vehicle's orbital plane.
Warning: The STK orbit propagator doesn't completely validate the correctness of the complete Orbit State specified. This means that Connect may return a positive acknowledgment when the orbit track can't be displayed. Connect performs the same validation that occurs from the entry of state data via the user interface.
To set the path for the ERS1 satellite using equinoctial elements and propagate the orbit:
SetState */Satellite/ERS1 Equi J4Perturbation "1 Nov 2000 00:00:00.00" "1 Nov 2000 08:00:00.00" 60 MeanOfEpoch "1 Nov 2000 00:00:00.00" 7163000.137079 0.0 0.0 0.55697636 -0.65743965 220.270122 Retrograde "1 Jan 2000 00:00:00.00"
To set the path for the ERS1 satellite using equinoctial elements and propagate the orbit over the scenario's analysis time period:
SetState */Satellite/ssEqui7 Equi J2Perturbation UseScenarioInterval 60 MeanOfEpoch "1 Nov 2008 00:00:00.00" 7163000.137079 0.0 0.0 0.55697636 -0.65743965 220.270122 Retrograde "1 Jan 2008 00:00:00.00"
If activated, Connect returns an acknowledgement message.
This command belongs to the following group(s):
10.1
STK Programming Interface 11.0.1