A HYBRID 3D ELECTROMAGNETIC MODELLING SCHEME
K.H. Lee · eScholarship (California Digital Library) · 2012
This paper presents an efficient numerical method for the electromagnetic scattering of arbitrary three-dimensional local inhomogeneities buried in a uniform or two-layered earth.In this scheme the inhomogeneity is enclosed by a volume whose conductivity is discretized by a finite element mesh and whose boundary is only a slight distance away from the inhomogeneity, The scheme uses two sets of independent equations.The first is comprised of finite element equations derived from a variational integral, and the second is a methematical expression for the fields at the boundary in terms of the electric fields inside of the boundary.The Green 1 s function is used in the derivation of the second set of equations.An iterative algorithm has been developed using these two sets of equations.The solutions are the electric fields at nodes inside the finite element boundary, The scattered fields anywhere may then be obtained by performing volume integrations over the inhomogeneous region.This scheme has been used for modelling three-dimensional inhomogeneities in plane wave and magnetic dipole studies.The results confirm earlier model analyses using the finite element technique.