01. Evaluation of the accuracy of the global gravity field models EGM2008, EIGEN-6C4 and SGG-UGM-2 based on the detailed gravity data in the Red River delta

Abstract

The accuracy of global gravity field models EGM2008, EIGEN-6C4 and SGG-UGM-2 are evaluated based on detailed gravity data in the Red River delta in the North of Vietnam. The detailed gravity data and the respective gravity data from global gravity field models EGM2008, EIGEN-6C4, SGG-UGM-2 of 677 points are fixed to the same tidal system. In this research, correction values of the conversion between tidal systems are small so it is only theoretically significant. Research results have shown that, in the experimental area, the average gravity deviation of models EGM2008, EIGEN-6C4 and SGG-UGM-2 is +2,453 mgal, -4,193 mgal, -4,380 mgal, respectively. The accuracy of models EGM2008, EIGEN-6C4, and SGG-UGM-2 are equivalent, about 13 mgal. The information is useful for users when applying these models in practice. The accuracy of global gravity field models is determined scientifically and accurately. The process can be applied to other regions with similar data sources.