Adjustment of Galileo Satellite Orbits with VLBI Observations: A Simulation Study

Abstract

Observing Earth-orbiting satellites and quasars in parallel with Very Long Baseline Interferometry (VLBI) telescopes provides new capabilities such as precise orbit determination (POD) from VLBI observations. As the sensitivity of a satellite observation towards the individual components of the satellite position is dependent on the geometry of the observing stations and the satellite, not all possible satellite observations are equally suitable for orbit determination. We evaluate possible satellite observations in terms of their potential for determining the satellite orbits using Dilution of Precision (DOP) factors, which are indicators for the sensitivities of a satellite observation. We compare the performance of satellite observations having different sensitivities to the satellite position and the precision of the adjusted orbit arc resulting from Monte Carlo simulations of these observations. This study shows that the results of the precision of the adjusted orbit arcs and the values of the DOP factors concur, and therefore possible satellite observations can be evaluated in advance in the scheduling process using DOP factors.