Efficient and Rapid Estimation of the Accuracy of Future GRACE Follow‐on Earth's Gravitational Field Using the Analytic Method

Abstract

AbstractThe accuracy of Earth's gravitational field from the Gravity Recovery and Climate Experiment (GRACE) Follow‐On satellite mission is efficiently and rapidly estimated for the first time based on the analytic method. Firstly, the new single and combined analytic error models of cumulative geoid height influenced by four error sources including the intersatellite range‐rate of interferometric laser ranging system, orbital position and velocity of GPS receiver and nonconservative force of accelerometer from GRACE Follow‐On satellites are established using the power spectrum principle, respectively. Secondly, the dependability of analytic error model is validated according to the consistency of the matching accuracy indexes of GRACE key payloads from the single analytic error models and the GRACE Level 1B provided by the American Jet Propulsion Laboratory (JPL), and the conformity of GRACE cumulative geoid height errors from the combined analytic error model and the Earth's gravitational field model EIGEN‐GRACE02S released by the German GeoForschungsZentrum Potsdam (GFZ). Finally, the influences of different matching accuracy indexes of key payloads and orbital altitudes of GRACE Follow‐On satellites on the accuracies of Earth's gravitational field are demonstrated contrastively. At the 360 degree, cumulative geoid height error is 1.231×10−1 m using combined analytic error model based on orbital altitude 250 km, intersatellite range 50 km, intersatellite range‐rate error 1×10−9 m/s, orbital position error 3×10−5 m, orbital velocity error 3×10−8 m/s and nonconservative force error 3×10−13 m/s2. This work not only can provide the theoretical foundation and calculational guarantee for the efficient and rapid determination of the accuracies of current GRACE and future GRACE Follow‐On Earth's gravitational field, but also has some reference significance to the successful execution of the future Gravity Recovery and Interior Laboratory (GRAIL) lunar satellite gravity exploration mission.