Study on refinement method of urban-level regional quasi-geoid with earth gravity field model
In view of the large regions with complex terrain and difficulties in collecting gravity data in urban areas,a method called"remove-restore"technique that takes into account the earth gravity field model is proposed to accurately describe the geoid surface in this paper.Taking the measured data of a prefecture-level city as an example,the polyhedral function,the moving surface method,and the"remove-restore"method considering the EGM2008 and EIGEN-6C4 earth gravity field models were used to fit the quasi-geoid.The results of various schemes were compared and analyzed using the measured GNSS/level data and the high-precision quasi-geoid model already available in the city.The results show that the accuracy of the polyhedral function method is better than that of the moving surface model method.Considering the higher fitting accuracy of the earth gravity field model methods compared to the simple function model methods;Although the EIGEN-6C4 earth gravity field model has slightly better accuracy than the EGM2008 earth gravity field model in the experimental area,it does not significantly improve the accuracy of the final quasi-geoid model.
quasi-geoidelevation anomalyGNSS/levelingEGM2008EIGEN-6C4polyhedral function
NETL
NSTL
万方数据
