3D forward modeling for frequency AEM by vector finite element

The finite-element method and application in EM exploration are well-developed. However, applications of the technology are focused mostly on ground and marine EM. Little attention has been put on airborne EM. Based on the previous research, we work on three-dimensional (3D) modeling for airborne systems by vector finite-element. We apply double-curl inhomogeneous vector Helmholtz equation for the second field and obtain the variational equations by using the generalized variational principle. By dividing the model domain into hexahedral elements and putting the field on the edge, we use linear interpolation for each element and put them together to set up the linear equations. For the multiple-source problem of AEM, we use the MUMPS solver that could achieve satisfying results both on speed and accuracy. We test the stability of our algorithm on a single abnormal body model first and check the practicability of the algorithm by simulating on typical geoelectrical models. The model results show that the overburden and the vertical contacting zone have great influence on the AEM responses. © 2016, Editorial Department of Earth Science. All right reserved.