Effect of Orbital a Priori Information on Baseline Determinations

There is continuously increasing demand for very accurate baselines, especially over long distances. Such accurate baselines are required for geodynamic studies, orbit generation, and for very precise geodetic applications. Therefore, in order to achieve baseline accuracies around ${10}^{-7}-{10}^{-8}$ by using GPS techniques, realistic a priori stochastic information for parameters must be considered in the future. Several data sets of simulated GPS measurements for a ground network are created and adjusted while taking into consideration both errorless as well as erroneous orbital information. The adjustment results clearly indicate the influence of erroneous orbital information on the baselines. It is also observed that by incorporating the orbital uncertainty information in the adjustment, the baseline results are significantly improved. The consideration of a priori information of additional parameters such as ground coordinates, etc., further upgraded the results.