Precision Analysis of SST Gravity Field Model in China

In this paper,with China as the region in test,the potential of the new satellite gravity technique,satellite-to-satellite tracking,to improve the precision of regional gravity field model is studied.With WDM94 as reference,the gravity anomaly residuals of three models,the latest two GRACE global gravity field models(EIGEN_GRACE02S,GGM02S) and EGM96,are computed and compared.The causes for the differences among the residuals of the three models are discussed.The comparison between the residuals shows that in the selected region,EIGEN_GRACE02S or GGM02S is better than EGM96 in lower degree part(less than 110 degree).From the analysis of the model gravity anomaly residuals,it is found that some systematic errors with periodical properties exist in the higher part of EIGEN and GGM models.The results of the paper can also be taken as references in the validation of the SST gravity data.