首先，对美国喷气推进实验室（JPL）公布的2007-06-01～2007-12-31时间段内的GRACE-Level-1B卫星GPS轨道位置和速度、K波段系统星间速度、加速度计非保守力、以及恒星敏感器姿态实测数据对应进行了轨道拼接、粗差探测、线性内插、重新标定、坐标转换、误差分析等有效处理；其次，基于改进的能量守恒法恢复了120阶GRACE地球重力场，在120阶处累计大地水准面精度为25.313 cm；最后，检验了本文建立的地球重力场模型IGG-GRACE的可靠性，同时分析了IGG-GRACE解算精度在低频部分略优于德国波兹坦地学研究中心（GFZ）公布的EIGEN-GRACE02S地球重力场模型，而在中高频部分略低的原因。
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.
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