Simulation of Recovery of Geopotential Model Based on the Intersatellite Acceleration Data in Low-Low Satellite to Satellite Tracking Gravity Mission

Abstract

In LL-SST gravity mission, the intersatellite range and range-rate data are the direct observable values, while the intersatellite acceleration can also be derived from the range-rate through digital differentiation. Using acceleration data, people could avoid the solving for the variational equations of satellite motion and simplify the observation equations, but on the other side, the digital differentiation will amplify the observation noises and finally affect the solved geopotential accuracy. In order to give a quantitative answer, this paper analyses and detects the accuracy of calculated acceleration by digital differentiation, derives the general observation equations with the intersatellite acceleration and simulates the geopotential solution based on the acceleration data. The results show that the solution accuracy by using the acceleration observation is much lower than the accuracy obtained from range-rate observation.