Predicting bathymetry based on vertical gravity gradient anomaly and analyses for various influential factors  

作　　者：Huan Xu Jinhai Yu Yanyan Zeng Qiuyu Wang Yuwei Tian Zhongmiao Sun 

机构地区：[1]College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing,China [2]Beijing Institute of Surveying and Mapping,Beijing,China [3]National Key Laboratory of Geoinformation Engineering,Xi'an 710054,China

出　　处：《Geodesy and Geodynamics》2024年第4期386-396,共11页大地测量与地球动力学（英文版）

基　　金：funded jointly by the National Nature Science Funds of China(No.42274010);the Fundamental Research Funds for the Central Universities(Nos.2023000540,2023000407).

摘　　要：The prediction of bathymetry has advanced significantly with the development of satellite altimetry.However,the majority of its data originate from marine gravity anomaly.In this study,based on the expression of vertical gravity gradient(VGG)of a rectangular prism,the governing equations for determining sea depths to invert bathymetry.The governing equation is solved by linearization through an iterative process,and numerical simulations verify its algorithm and its stability.We also study the processing methods of different interference errors.The regularization method improves the stability of the inversion process for errors.A piecewise bilinear interpolation function roughly replaces the low-frequency error,and numerical simulations show that the accuracy can be improved by 41.2%after this treatment.For variable ocean crust density,simulation simulations verify that the root-mean-square(RMS)error of prediction is approximately 5 m for the sea depth of 6 km if density is chosen as the average one.Finally,two test regions in the South China Sea are predicted and compared with ship soundings data,RMS errors of predictions are 71.1 m and 91.4 m,respectively.

关 键 词：Rectangular prism Vertical gravity gradient BATHYMETRY Numerical simulation Prediction error 

分 类 号：P223.39[天文地球—大地测量学与测量工程]