Implications of the Application of Recursive Least Squares Algorithms to Satellite Orbit Determination Using GPS Measurements

Abstract: The main target here is to determine the orbit of an artificial satellite and to analyze its implications, using least squares algorithms through sequential Givens rotations as the method of estimation, and data of the GPS receivers. This approach longs for to improve the performance of the orbit estimation process and, at the same time, to minimize the computational procedure cost. Perturbations due to high order geopotential and direct solar radiation pressure were taken into account. The position of the GPS antenna on the satellite body that, lately, consists of the influence of the satellite attitude motion in the orbit determination process, was also considered. An application has been done, using real data from the Topex/Poseidon satellite, whose ephemeris were available. In a process of high accuracy orbit determination, frequently a sinusoidal residual behavior is observed during its error analysis. Actually, it is the result of unmodeled residual accelerations, which present frequencies near or multiple to the satellite period and appear by different reasons. Assuming that we cope with the unmodeled accelerations, which have no direct physical reasons, or that the modeling effort is not worthwhile, such accelerations will also be analyzed, empirically