使用能量守恒方法恢复CHAMP地球重力场

CHAMP gravity field recovery using the energy conservation method

本文探讨了基于能量守恒方法利用CHAMP卫星精密星历和加速度数据恢复地球重力场模型的原理和方法。给出了地心惯性系下顾及地球自转和非保守力能量损耗的能量守恒方程,并且对日、月摄动位与引潮力附加位的计算方法作了相应的分析,同时介绍了加速度数据的处理方法。基于能量守恒方法,利用2002年1-2月、7-8月和11-12月三个不同时期共180天的CHAMP卫星精密星历和加速度数据恢复了三组50阶次的地球重力场模型GFM01、GFM02和GFM03,并将这些模型与EGM 96重力场模型和GFZ公布的EIGEN-CG01C重力场模型进行比较。结果表明:能量守恒方法恢复的GFM系列模型与EGM 96重力场模型及EIGEN-CG01C重力场模型在低阶位系数上均有较好的一致,但与EIGEN-CG01C模型有更好的一致。这说明了CHAMP卫星对地球中、长波重力场的敏感性,也说明了能量守恒方法恢复低阶地球重力场位系数的有效性。

In this paper,the theory and method of gravity field recovery using CHAMP satellite PSO(post-processed science orbit)data and accelerometer data based on the energy conservation method were discussed.After considering the earth rotation and non-conservative forces energy dissipation,the energy conservation equation was presented.The formula of the gravitation potential and tide-generating force additional potential of sun and moon were given in detail. The disposal of accelerometer data was introduced.Based on the energy conservation theory,using 180 days CHAMP satellite PSO and accelerometer data in three different periods of month 1-2,7-8 and 11-12,2002,three global gravity field models of 50 degree that named GFM01,GFM02 and GFM03 were recovered.These gravity field models were compared with models EGM96 and EIGEN-CG01C.The results showed that the series GFM gravity field models recovered by the energy conservation method were well consistent with EGM96 and EIGEN-CG01C gravity field models in low-degree potential coefficients,but they were in a better agreement with EIGEN-CG01C models.All these indicated that CHAMP is sensitive in medium and long wavelength of global gravity field and the energy conservation method is an efficient one for recovery low-degree potential coefficients of global gravity field.