Covariance analysis for deep-space satellites with radar and optical tracking data

Covariance analysis for the special perturbations orbit determination problem for deepspace satellites is considered to determine the relative merit of radar and optical tracking data. Deep-space radars provide very accurate range measurements, but less accurate angle measurements. Optical sensors provide very accurate angle measurements, but make no range measurements since they are passive systems. The relationship of the size of the spatial part of the covariance to the relative track density of radar and optical tracks in the orbit determination fit interval is illustrated for satellites in semi-synchronous circular orbits. Similar results apply to highly eccentric semi-synchronous and geosynchronous orbits.