Short-Arc Batch Estimation for GPS-Based Onboard Spacecraft Orbit Determination

In dynamic orbit determination, the problem is that a batch estimator assumes use of more sophisticated models for both force and observation models, dealing with large amounts of observations. As a result, the computational workload may not be acceptable for onboard orbit determination. In this paper, the short-arc batch estimation is experimentally studied in order to address both estimation robustness and computational problems in GPS-based onboard orbit determination. The technical basis for the batch estimation will be outlined. The experimental results from three 96-hour data sets collected from Topex/Poseidon (T/P), SAC-C and CHAMP missions are presented. These results have demonstrated that use of shorter data arcs allow for simplifications of both orbit physical and observational models, while achieving a 3D RMS orbit accuracy of meter level consistently.