Orbit Uncertainty

These fields represent, in the form of a list of properties, a covariance matrix for errors in radial (R), in-track (I) and cross-track (C) position and velocity.

R_sigma RI_correlation RC_correlation RRdot_correlation RIdot_correlation RCdot_correlation
... I_sigma IC_correlation IRdot_correlation IIdot_correlation ICdot_correlation
... ... C_sigma CRdot_correlation CIdot_correlation CCdot_correlation
... ... ... Rdot_sigma RdotIdot_correlation RdotCdot_correlation
... ... ... ... Idot_sigma IdotCdot_correlation
... ... ... ... ... Cdot_sigma

In the diagonal from radial position (R_sigma) to cross-track velocity (Cdot_sigma), enter the estimated errors for the respective position or velocity elements. In each off-diagonal field appearing in a row i and column j, enter a value ri j, where

-1 <= ri j <= 1

and represents the covariance between the errors for the elements heading the ith row and the jth column of the matrix.

When the satellite EstimateOrbit flag is set to true, the orbit uncertainty is used to compute the initial covariance for the satellite when the filter is run in initial mode and is used by the simulator to produce deviates of the initial orbit state. The orbit uncertainty can also be used to specify a constant uncertainty in the RIC frame for a satellite using a reference ephemeris. To be interpreted in this manner, the EstimateOrbit flag must be set to false, a reference ephemeris must be specified and the CovarianceSource for the reference ephemeris must be set to Constant.

ODTK 6.5