Forward Modeling of Frequency Domain Controlled-Source Electromagnetic Using Finite Element Method

Frequency domain controlled-source electromagnetic (fCSEM) is an artificial source electromagnetic sounding method, which developed on the basis of magnetotelluric sounding. For showing the fCSEM forward modeling result, numerical simulation method must be adopted. In this paper. Base on Matlab as programming tool, we adopted the finite element method of quadratic interpolation in a rectangular element for solving the fCSEM forward problem and derived the corresponding formula for calculating. In order to simulate the infinity border and meet the demand computer memory, the nonuniform gird is designed with ensuring the accuracy. In programming, we only stored the non-zero elements of the finite element matrix for reducing the forward calculation time. By numerical simulation of homogeneous half-space model and 2-D model, we verified the correctness of the forward modeling algorithm.