Hybrid PSM/FDM method for seismic wavefield simulation

Abstract:The pseudospectral approach is an efficient and accurate numerical method for seismic wave modeling in heterogeneous medium. However, due to the global nature of its spatial derivative operator, it is difficult to implement this method in parallel computation on distributed memory cluster system. In this paper, we propose a hybrid scheme based on the pseudospectral method (PSM) and finite difference method (FDM), which combines the local nature of the FDM operator and the high accuracy and efficiency of PSM. In the hybrid method, the spatial derivative in one of the space coordinates is approximated using the high order staggered grid FDM, while in other coordinates are approximated by staggered PSM. This method retains the advantages of the PSM and can be easily implemented on a parallel PC cluster for large scale parallel computation. Numerical tests for 2D models showed that the hybrid method can be used to effectively calculate seismic wavefield in heterogeneous medium, and it provides a possible parallel scheme without loosing accuracy of the results.