Recursive Least Squares Algorithms Applied to Satellite Orbit Determination, Using GPS Signals

Using signals of the GPS constellation and least squares algorithms through sequential Givens rotations as a method of estimation, the principal target is to determine the orbit of an artificial satellite. This approach aims to improve the performance of the orbit estimation process and, at the same time, to minimize the computational procedure cost. Perturbations up to high order geopotential and direct solar radiation pressure were taken into account. It was also considered the position of the GPS antenna on the satellite body. An application has been done, using real data from the TOPEX/POSEIDON satellite. In a process of high accuracy orbit determination, frequently a sinusoidal residual behavior is observed during its error analysis. Assuming that we cope with the unmodeled accelerations, which have no direct physical reasons, or that the modeling effort is not worthwhile, these anomalous accelerations will also be analyzed, empirically.