Contraction preconditioner in finite-difference electromagnetic modeling

摘要

This paper introduces a novel approach to constructing an effective preconditioner for finite-difference (FD) electromagnetic modeling in geophysical applications based on an FD contraction operator, similar to one developed for integral equation formulation of Maxwell's equation. The contraction properties of this operator were established using an FD analog of the energy equality for the anomalous electromagnetic field. We have also developed the formulas for an estimation of the condition number of the system of FD equations preconditioned using the introduced FD contraction operator. The numerical examples illustrate the practical effectiveness of the developed method for modeling 3D marine controlled-source electromagnetic data.