Set options for the HPOP force model
HPOP <ObjectPath> Options {ForceModelOption} <ModelParameters>
The HPOP Options command enables you to set additional force model options to control certain settings that influence the propagation of a satellite's or missile's orbit using the High-Precision Orbit Propagator (HPOP) module.
This command is valid for Satellites and Missiles.
{ForceModelOption} and <ModelParameters> are:
| {ForceModelOption} | <ModelParameters> | Description |
|---|---|---|
| ApproxAltForDrag | {On | Off} | Set flag for the drag model to use an approximate expression to determine altitude, instead of finding the exact altitude, when computing density. |
| ApparentSunForDrag | {On | Off} | Set flag to use apparent sun position rather than true sun position. |
| SunPositionMethod | {True | Apparent | ApparentToTrueCB} | Specify the direction of the Sun for SRP computations. |
| AtmoAltitude | <Altitude> | <Altitude> is entered in Connect distance units and is between 0.001 and 1000.0. |
| AltitudeCutoff | <Altitude> | Set the minimum altitude for propagation. <Altitude> is entered in Connect distance units and is between 0.0 and 1000000.0. |
| Mass | <MassValue> | Enter a satellite mass to be used in
atmospheric drag and solar radiation pressure calculations.
<MassValue> is entered in Scenario mass units and is greater
than 0.0.
Note: This option attempts to keep the area constant, so the area/mass ratio will change when the Mass is changed. |
| FluxUpdate | {Daily | 3Hour | 3HourInterp | 3HourCubicSpline} | Set the frequency for updating geomagnetic flux values, when using a flux file to compute density for drag. |
| IncludeRelAccel | {On | Off} | Set flag to include relativistic accelerations. |
| PropPlugin | {On | Off} ["<PropPluginName>"] | Specify a registered single force model plugin for the customization of the accelerations used in the propagation of the satellite trajectory. The "<PropPluginName>" is required if On is selected. |
| GeoMagFluxSource | {Kp | Ap} | Specify whether to use the kp or ap data from the flux file. |
Note: For this command to be valid, the satellite or missile must already be defined as using the HPOP propagator.
To use apparent sun position and specify Apparent for the direction of the Sun for SRP computations:
HPOP */Satellite/Satellite1 Options ApparentSunForDrag On SunPositionMethod Apparent
To set the minimum altitude for propagation to 300.0 meters:
HPOP */Satellite/Satellite1 Options AltitudeCutoff 300.0
If activated, Connect returns an acknowledgement message.
This command belongs to the following group(s):
9.0
STK Programming Interface 11.0.1