Error analysis of a low-low satellite-to-satellite tracking mission

The Gravity Recovery and Climate Experiment is a dedicated spaceborne mission whose objective is to map the gravity field with unprecedented accuracy. It consists of two satellites coorbiting in a nearly polar orbit at low altitude. Primary measurements are a series of measured range changes between the two satellites using a dual one-way microwave ranging system. These measurements are combined with accelerometer and global positioning system measurements. In this study, comprehensive simulation models for these major instruments have been developed to recover the gravity information. Effects of the primary error sources on the orbit and gravity estimation are analyzed through a series of numerical simulations.