Evaluating gravity gradient components based on a reweighted inversion method*
Cao Ju-Liang, Qin Peng-Bo, and Hou Zhen-Long
1. College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410000, China
2. GuangZhou Marine Geological Survey, Guangzhou 510000, China
3. School of Resources and Civil Engineering, Northeastern University, Shenyang 110819, China
Abstract：
In gravity gradient inversion, to choose an appropriate component combination is very important, that needs to understand the function of each component of gravity gradient in the inversion. In this paper, based on the previous research on the characteristics of gravity gradient components, we propose a reweighted inversion method to evaluate the influence of single gravity gradient component on the inversion resolution The proposed method only adopts the misfi t function of the regularized equation and introduce a depth weighting function to overcome skin effect produced in gravity gradient inversion. A comparison between different inversion results was undertaken to verify the influence of the depth weighting function on the inversion result resolution. To avoid the premise of introducing prior information, we select the depth weighting function based on the sensitivity matrix. The inversion results using the single-prism model and the complex model show that the influence of different components on the resolution of inversion results is different in different directions, however, the inversion results based on two kind of models with adding different levels of random noise are basically consistent with the results of inversion without noises. Finally, the method was applied to real data from the Vinton salt dome, Louisiana, USA.
2019, Vol. 16 
