Acta Geodaetica et Cartographica Sinica ›› 2024, Vol. 53 ›› Issue (5): 900-916.doi: 10.11947/j.AGCS.2024.20230132

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Band-limited SRBF quadratic approximation method for local gravity fields in complex regions

Zhiwei MA1(), Shaofeng BIAN2, Ruyi XU3, Yongbing CHEN2   

  1. 1.School of Engineering Management and Real Estate, Henan University of Economics and Law, Zhengzhou 450046, China
    2.School of Electrical Engineering, Naval University of Engineering, Wuhan 430033, China
    3.School of Finance, Henan University of Economics and Law, Zhengzhou 450046, China
  • Received:2023-05-08 Revised:2024-04-02 Published:2024-06-19
  • About author:MA Zhiwei (1986—), male, PhD, lecturer, majors in methods for multi-source gravity data fusion and local gravity field modeling. E-mail: jzmazhiwei@163.com
  • Supported by:
    The National Natural Science Foundation of China(42104087)

Abstract:

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 0.022 m. This suggests the effectiveness of merging GGM and airborne gravity data for initial modeling. Subsequently, 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 yielded reductions of 0.036 m and 0.024 m 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.

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

CLC Number: