CHAMP Gravity Field Recovery Based on Variance Component Estimation

Considering the different precision level of observation arcs due to the influence of space environment and instruments stability,a new method for CHAMP gravity field recovery based on variance component estimation is presented.This method can reasonably determine the weights of different observation arcs and balance their contributions to the estimated potential coefficients.A 50 degree and order gravitational potential model XISM-CHAMP01 is recovered using 100 days' CHAMP kinematic orbits provided by TUM and accelerometer data provided by GFZ.The RMS among XISM-CHAMP01,EIGEN-CG03C,EIGENCHAMP03S,EIGEN2,ENIGN1S and EGM96 are compared.The results show that XISM-CHAMP01 model is more accurate than EGM96 and EIGEN1S model at the same degree and order,and has almost the same accuracy as EIGEN2 model