Seafloor Density Contrast And Bathymetry Inversion Based On Gravity Data

The high-precision,high-resolution bathymetry model is the basis of marine scientific research and ocean utilization,it plays an important role and has practical application value.In this paper,based on the shortcomings in the process of inversion of bathymetry by Gravity Geology Method,proposed the method of determining the density contrast by total least squares and long-wavelength gravity anomaly model based on adaptive triangular mesh,the existed gravity geology method is improved.Predicted the bathymetry in MH370 area.Inversion analysis and evaluation was completed.The main research contents are as follows:1.Analyzed the importance of high-precision and high-resolution bathymetry models for human survival and development;Summarized the development and status of technology and inversion methods for obtaining bathymetry;Introduced the common bathymetry models,and a brief analysis of global sea depth is made based on ETOPO1 model.2.Introduced the conventional solution for determining the density contrast,and compared the advantages and disadvantages of the solutions.At last,taking into account the observation error of gravity anomaly and shipborne depth database,proposed the idea and method of determining density contrast by the global least squares method based on the basic formula of gravity geological method,determined the density contrast.3.Aiming at the problem of losing accuracy in constructing modeling of long-wavelength gravity anomaly with regular rectangular grid,researched the idea and algorithm of constructing modeling of long-wavelength gravity anomaly by using adaptive finite element method,and the existing gravity geology method is improved.Based on the improved gravity geology method,in the MH370 search area,completed the bathymetry inversion experiment and analysis by altimetry gravity data and ship bathymetric data.Proved the inversion effect of iGGM is better than the original gravity geological method(GGM),iGGM can further improve the inversion accuracy of bathymetry.At last,analyzed the main factors affecting the inversion accuracy by MH370 data.