Effective Processing of Measured Data from GRACE Key Payloads and Accurate Determination of Earth's Gravitational Field

Abstract Firstly, the GRACE Level 1B measured data including the orbital position and velocity of GPSreceiver, intersatellite range rate of K-band ranging system, nonconservative force of accelerometer and attitudeof star camera assembly between 2007-06-01∼2007-12-31 provided by the American Jet Propulsion Laboratory(JPL) are processed effectively by orbital connection, gross error detection, linear interpolation, recalibration,coordinate transformation, error analysis, and so on. Secondly, the GRACE Earth’s gravitational field completeup to degree and order 120 is recovered based on the improved energy conservation principle, the cumulativegeoid height error is 25.313 cm at degree 120. Finally, the dependability of the Earth’s gravitational field modelIGG-GRACE is verified in the paper, and the reasons why the accuracy of IGG-GRACE is a little superior to theEarth’s gravitational field model EIGEN-GRACE02S provided by the German GeoForschungsZentrum Potsdam(GFZ) in the low frequency range and is slightly lower than that in the medium-high frequency band are analyzed.Key words GRACE, Key payloads, Measured data, Energy conservation principle, Earth’s gravitational field