Set options for HPOP Covariance model
HPOP <ObjectPath> Covariance {CovarOption} <Parameters>
The HPOP Covariance command allows the user to input an initial state error covariance matrix. HPOP is capable of propagating the state error covariance matrix as it is propagating ephemeris. The state error covariance matrix represents the uncertainty in the vehicle's position and velocity. The vehicle's position covariance submatrix can then be reported and graphed and can be displayed in the 3D Graphics window over time.
This command is valid for Satellites and Missiles.
| {CovarOption} <Parameters> | Description |
|---|---|
| On | Turn on the propagating of the state error covariance matrix as the ephemeris is being propagated. |
| Off | Turn off the propagating of the state error covariance matrix as the ephemeris is being propagated. |
| Gravity <MaxDegree> <MaxOrder> | Indicate the number of terms to use in the gravity field when propagating the state error covariance matrix. Valid values are 0 to 100. |
| Frame {J2000 | LVLH | Frenet | TrueOfDate} | Indicate the frame in which the covariance matrix, as well as the consider parameter position/velocity cross-correlations, is being input. |
| Representation {Cartesian} | Indicate how the position/velocity covariance is represented. |
| Consider {On | Off} | Indicate whether or not consider parameters should be included when propagating covariance. |
| PosVel <xx> <yx> <yy> <zx> <zy> <zz> <Vxx> <Vxy> <Vxz> <VxVx> <Vyx> <Vyy> <Vyz> <VyVx> <VyVy> <Vzx> <Vzy> <Vzz> <VzVx> <VzVy> <VzVz> | Enter the 21 values representing the lower triangle of the 6x6 position velocity sub matrix. |
| ConsiderParam <Parameters> | See the table below for description of the parameters available for this option. |
The following table describes the <Parameters> for the setting up consider parameters and cross-correlation effects.
| <ConsiderParameters> | Description |
|---|---|
| <Name> Remove | Remove the named consider parameter from inclusion when propagating covariance. |
| <Name> <Self> <x> <y> <z> <vx> <vy> <vz> | Set values for the named consider parameter. The <Self> value corresponds to the self-covariance of that parameter (i.e. the value that appears as the diagonal element of Pww); the other values are for entering cross-correlations between that parameter and position/velocity covariance. |
| <Name1> <Name2> <Value> | To model cross-correlation effects choose the two consider parameters (<Name1> <Name2>) that have the correlation, and enter the cross-correlation (<Value>). |
The following series of commands will set up the use of Covariance propagation for Satellite1:
hpop */Satellite/Satellite1 Covariance On
hpop */Satellite/Satellite1 Covariance Gravity 4 2
hpop */Satellite/Satellite1 Covariance PosVel 100. 0.0 400. 0.0 0.0 900. 0.0 0.0 0.0 16. 0.0 0.0 0.0 0.0 25. 0.0 0.0 0.0 0.0 0.0 36.
hpop */Satellite/Satellite1 Covariance ConsiderParam Drag 0.1 0.0 0.0 0.0 0.0 0.0 0.0
hpop */Satellite/Satellite1 Covariance ConsiderParam SRP .4 0.0 0.0 0.0 0.0 0.0 0.0
hpop */Satellite/Satellite1 Covariance ConsiderParam Drag SRP .16
This command belongs to the following group(s):
8.0
STK Programming Interface 11.0.1