DOWNWARD CONTINUATION OF SATELLITE GRAVITY GRADIENT DATA
Liu Xiaogang 1) ;Li Shanshan 1) ; and Wu Xing 2,3)
1)Institute of Surveying and Mapping, Information and Engineering University, Zhengzhou 4500522)Center for Engineering Design and Research Under the Headquarters of General Equipment, Beijing 1000283)Institute of Hydrographic Survey and Charting, Tianjin 300061
Abstract Downward continuation is one of the indispensible steps in preprocessing satellite gravity gradient data when recovering the earth gravity field with spacewise method. The spherical interior Dirichlet method, the Poisson integral iteration method and the spectral method, which are used in the processing of aerial gravity data, are introduced into the downward continuation of satellite gravity gradient data, the corresponding mathematical models are constructed, the numerical value inconsistency in the traditional spherical interior Dirichlet problem is also solved, and the downward continuation effects of these three methods are analyzed and discussed by taking the simulated satellite gravity gradient data as the example. The results show that when the continuation distance is 5 km, the resultant continuation precision of the spectral method is the best, the spherical interior Dirichlet methods’ is the second, and the Poisson integral iteration methods’ is the last; when the continuation distance is 250 km, the resultant continuation precision of the Poisson integral iteration method is the best, the spectral methods’ is the second, and the spherical interior Dirichlet methods’ is the last.
