On a Feasibility of Modeling Temporal Gravity Field Variations from Orbits of Non-dedicated Satellites

Abstract

A numerical study has been conducted in order to analyze under what conditions temporal variations of the Earth's gravity field can be recovered from the orbit of a satellite that is not equipped with an accelerometer. In the study, the motion of one of GRACE satellites was reproduced. A variant of the acceleration approach was used to process the simulated data. It turned out that the presence of non-gravitational satellite accelerations does not obscure temporal gravity field variations, provided that the satellite orbit (and, consequently, the set of observed satellite accelerations) is noise-free. Therefore, inaccuracies of the orbit determination is the only reason why a satellite orbit cannot be used to monitor temporal gravity field variations. It is shown that these inaccuracies should be reduced 30-100 times with respect to the level reached currently for the CHAMP and GRACE mission. Of course, a simultaneous utilization of data from several satellites can make this requirement less stringent. © Springer-Verlag Berlin Heidelberg 2009.