On a Robust Iterative Method for Heterogeneous Helmholtz Problems for Geophysics Applications

Abstract

In this paper, a robust iterative method for the 2D heterogeneous Helmholtz equation is discussed. Two important ingredients of the method are evaluated, namely the Krylov subspace iterative methods and multigrid based preconditioners. For the Krylov subspace methods we evaluate GM-RES and Bi-CGSTAB. The preconditioner used is the complex shifted Laplace preconditioner [Erlangga, Vuik, Oosterlee, Appl. Numer. Math. 50(2004) 409-425] which is approximately solved using multigrid. Numerical examples which mimic geophysical applications are presented.