CHAMP Gravity field recovery based on the improved energy conservation approach
基于改进的能量守恒方法恢复CHAMP重力场模型

One of the most efficient method for gravity field determination from satellite observations of CHAMP is the energy conservation approach.In this paper,an improved energy conservation approach is presented and the corresponding formulas are derived.This method can provide an integer estimate on potential coefficients,integral constant,scale factor and bias parameter.A 60 degree and order gravitational potential model XISM-CHAMP1S is determined using about 300 days' CHAMP kinematic orbits from TUM and accelermeter data from GFZ.The comparisons among XISM-CHAMP1S,EIGEN-CG03C,EIGEN-CHAMP03S,EIGEN2,ENIGN1S and EGM96 are made.The results show that XISM-CHAMP1S model is more accurate than EGM96,EIGEN1S and EIGEN2 at the same degree and order,and has almost the same accuracy as EIGEN-CHAMP03S.