Effective Processing of Measured Data from GRACE Key Payloads and Accurate Determination ofEarth’s Gravitational Field 

Firstly, the GRACE-Level-1B measured data including the orbital position and velocity of the GPS receiver, the intersatellite range-rate of the K-band ranging system, the non-conservative force of the accelerometer and the attitude of the star camera assembly between 2007-06-01～2007-12-31 provided by the American Jet Propulsion Laboratory (JPL) are effectively processed by orbital connection, gross error detection, linear interpolation, recalibration, coordinate transformation, error analysis, and so on. Secondly, the Earth’s gravitational field from GRACE complete up to degree and order 120 is recovered based on the improved energy conservation principle, the cumulative geoid height error is 25.313 cm at degree 120. Finally, the dependability of the Earth gravity field model IGG-GRACE is verified in this study, and the reasons why the accuracy of IGG-GRACE is a little superior to the Earth gravity field model EIGEN-GRACE02S released 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. 

图1 动能，耗散能，位旋转能，太阳引力位，月球引力位，地球固体潮位和中心引力位

图2 GRACE全球重力场模型精度

Wei Zheng, Houtse Hsu, Min Zhong, Meijuan Yun. Effective processing of measured data from GRACE key payloads and accurate determination of Earth’s gravitational field. Chinese Journal of Geophysics, 2009, 52(4): 772-782.