Research Of Magnetic Anomaly Inversion Technology In The Presence Of Significant Remanence

In this paper,the three-dimensional magnetic anomaly inversion under strong remanence is studied.The magnetic inversion and magnetic remanence vector are used to enrich the magnetic inversion results and improve the accuracy of magnetic anomaly interpretation.Firstly,the unstructured grid finite element method is used to consider both the magnetic permeability and the remanence vector.The unstructured grid finite element algorithm is more suitable for complex model calculation,and has higher calculation speed.The performance provides protection.On the basis of finite element forward modeling,the inversion of magnetic permeability and the inversion of magnetic permeability and remanence vector are carried out respectively.The inversion objective function of 3D magnetic data is established,and the target is solved by Gauss-Newton method.The function is iteratively solved;in order to reduce the memory usage,the finite memory technology is adopted,and the product of the sensitivity matrix and its transposition and vector is calculated by forward modeling,thereby avoiding the storage of the sensitivity moment and the Hessian matrix.Finally,the effectiveness of the proposed algorithm is verified by the inversion of theoretical data and measured data.