Utilizing the SRBF-based two-step cumulative approximation method, this study conducted a detailed numerical analysis and validation for the construction of a local gravity field model in complex areas. First, data from the global gravity field model were combined with airborne gravity data to construct the initial SRBF-based gravity field model for the study area (the first gravity field approximation based on band-limited SRBFs).When compared to the airborne-only gravity field model, the standard deviation of geoid height discrepancies between the initial gravity field model and GPS/leveling data decreased by approximately 0.022m. This suggests the effectiveness of merging GGM and airborne gravity data for initial modeling. Subse-quently, after removing the effects of the reference gravity field model, the initial gravity field model and the residual terrain model from the terrestrial and airborne gravity data, a secondary SRBF-based modeling process was conducted (the second gravity field approximation based on band-limited SRBFs). Compared to the one-step SRBF model, the two-step approach yiel-ded reductions of 0.036m and 0.024m in terms of STD and RMS, respectively, highlighting the superiority of the SRBF-based two-step cumulative approximation method. Moreover, the study area features a complex mountainous terrain, which can serve as a reference for constructing gravity field model in similar complex regions.
关键词
带限径向基函数/局部重力场二次累积逼近法/卫星重力数据/航空重力数据/地面重力数据
Key words
band-limited spherical radial basis function/two-step cumulative approximation method for local gravity field/GGM gravity data/airborne gravity data/terrestrial gravity data
维普
万方数据