Investigation of the effect of repeat orbits on GRACE gravity recovery

Abstract

The Gravity Recovery and Climate Experiment (GRACE) has been orbiting the Earth and determining its gravity field since 2002. Throughout the course of the mission, the orbital elements occasionally change such that the satellites enter a repeat ground track configuration. Repeat ground tracks result in reduced spatial resolution of the satellites, which poses problems in the context of gravity recovery. The monthly gravity solutions during these periods are examined and shown to have lower quality than usual. The characteristics of these repeat period solutions are identified and compared to a period of uniform coverage to illustrate the ways in which the solutions are degraded. An investigation into the underlying physical and computational sources of these errors is also presented.