GPS-Based LEO Orbits Referenced to the Earth's Center of Mass

Global Navigation Satellite System satellite clock solutions of the International Global Navigation Satellite System Service are aligned to the International Terrestrial Reference Frame origin. This strategy is not sufficient to model correctly the Low Earth Orbit (LEO) Global Positioning System (GPS) measurements, because the geocenter motion is not taken into account for the ground station positions in these solutions. In order to be consistent with the dynamic motion of a LEO satellite, and also with the other measurement systems where the geocenter motion can be modeled (e.g., Satellite Laser Ranging and Doppler Orbitography and Radiopositioning Integrated by Satellite), it is necessary to take into account or mitigate the miscentering effect of the constellation solution. In this paper, we use a parametric model representing the reference network translations, and this model can be adjusted in the OSTM/Jason-2 and Jason-3 LEO satellites orbit determination.