Services and Support for TOPEX/PODTG

During the TOPEWPoseidon (T/P) mission the Precision Orbit Determination Team Discovered large along track accelerations which were unexpected and of unknown origin. Significant effort was expended in explaining the nature of these accelerations and developing mathematical models for them. It was found that the primary contribution was from unbalanced solar radiation pressure forces acting on the solar panels. The results of this study and the study recommendations are contained in the attached paper by Kubitschek and Born. Also, during this contract, we investigated techniques for improving the T/P and Jason- 1 precision orbit determination accuracy. The Jason project has set a goal of achieving 1 cm radial orbit accuracy, which is a factor of 2-3 better than currently being achieved for T/P.