707 / 2024-09-19 09:24:51

Research on Multisource Gravity Data Fusion Methods in the Ross Sea, Antarctica

Gravity data fusion,wavelet transform,window weighting,wavelet decomposition

     The marine gravitational field offers gravity data that aids in the exploration of the shape and internal structure of the Earth, as well as exploring the mineral resources of the ocean and guaranteeing spaceflight and long-range weapon launches. At present, gravity field data are mostly obtained through ship-based gravity measurement and satellite altimetry inversion techniques. We collected many ship-borne gravity survey lines in the Ross Sea and obtained 1434 survey lines and 8101 crossover points in the study area, and the total length of efective survey lines was 98,204 km. After adjustment, the RMS of the crossover points was±1.92×10^-5 m/s². In this study, based on selecting different wavelet functions with different decomposition levels, the concept of window weighting was introduced, and the useful information of the SHGD and SAGD was further fused to acquire higher precision data.

       When we adopted 80% data fusion and the remaining 20% data validation, the RMS of the 80% data fusion result and the SHGD decreased from 3.34×10^-5 m/s² to 1.63×10^-5 m/s², significantly improving the accuracy of the data in the study area. When we compared the remaining non-fused data with the fusion results, the RMS was reduced from 3.08×10^-5 m/s² to 1.51×10^-5 m/s². When using traditional wavelet transform fusion methods for fusion, the RMS is 2.87×10^-5 m/s² (for non-fused data), and the accuracy of our fusion method for non-fused data is improved by 1.36×10^-5 m/s² (1.51×10^-5 m/s² vs 2.87×10^-5 m/s²).Therefore, this method can be applied to most gravity data derived from multiple techniques.