Configure the numerical integration scheme for orbit integration
HPOP <ObjectPath> Integrator {IntegratorOption} <Parameters>
The HPOP Integrator command allows you to configure the combination of the formulation of the equations of motion and the numerical integration technique to be used during orbit propagation for Satellites or Missiles.
This command is valid for Satellites and Missiles.
The following Table lists valid values for {IntegratorOption}, their associated parameters and a brief description of each.
| {IntegratorOption} | Description |
|---|---|
| IntegMethod {RK4 | RKF78 | RKV89Efficient | BS | GJ} | The integration method to be used in
propagating the orbit.
Note: The Integration method GJ (Gauss-Jackson) is not valid for Missiles. Note: If Integration method is set to RK4 or Gauss-Jackson then StepControl will be set to Fixed. |
| VOP {On | Off} | Use a variation of parameters in
universal variables formulation of the equations of motion. Valid
in combination with the RKF78 or BS Integration method.
Note: This option is not valid for Missiles. |
| RegTime {On | Off} [<Exponent> <NumStepsPerOrbit>] | Integrate the orbit using regularized
time with the provided exponent(n) used in the relation dS =
sqrt(mu) r^(-n) dt , where 0 < exponent >= 10. If On is
entered, also specify <Exponent> and
<NumStepsPerOrbit>. If Off is entered, additional parameters
are ignored.
Note: This option is not valid for Missiles. |
| StepControl {RelativeError <ErrTol> | Fixed} | Method of integration step size control. If the step size is controlled based on RelativeError then the <ErrTol> must be provided. 0 < ErrTol >= 1.0e-6. Relative error step size control is only valid for the RKF78 and BS integration methods. |
| MinStepSize <Value> | The minimum and maximum integration step size to be allowed via relative error control. These settings do not affect integration with a <Fixed> {StepControl}. |
| MaxStepSize <Value> | |
| CorrectionScheme {Full | Pseudo} | Use a full evaluation of the acceleration model at the end of a Gauss-Jackson integration step or use a pseudo-evaluation where only the two body acceleration is updated. Valid for the Gauss-Jackson integration method only. |
| ReportOnFixedStep {On | Off} | Set the flag to indicate that ephemeris is to be reported on a fixed time step. |
| InterpMethod {LaGrange | LaGrangeVOP | Hermite} <InterpOrder> [Reset] | Set the interpolation method.
<InterpOrder> is an integer between 0 and 29.
If InterpMethod is Hermite, then <InterpOrder> must be an odd number between 3 and 29. If the optional Reset parameter is entered then the current ephemeris will be reset to use the interpolation method. |
Note: For this command to be valid, the satellite or missile must already be defined as using the HPOP propagator.
To set the numerical integration procedure to the Runge-Kutta-Fehlberg 7(8) method and to use an integration step size selection based on a maximum allowed relative error of 1.0e-13 per step:
HPOP */Satellite/Sat1 Integrator IntegMethod RKF78 StepControl RelativeError 1.0e-13
To use a variation of parameters formulation of the equations of motion:
HPOP */Satellite/Sat1 Integrator VOP On
To integrate in regularized time with an exponent of 1.5, and 120 steps per orbit:
HPOP */Satellite/Sat1 Integrator RegTime On 1.5 120
To report the ephemeris on a fixed time step:
HPOP */Satellite/Sat1 Integrator ReportOnFixedStep On
To set the interpolation method to LaGrange, with an interpolation order of 17:
HPOP */Satellite/Sat1 Integrator InterpMethod LaGrange 17
If activated, Connect returns an acknowledgement message.
This command belongs to the following group(s):
10
STK Programming Interface 11.0.1