A Comparison of Finite-difference Grids for Anisotropic Elastic Modelling

We analyze and compare the computational requirements, and dispersion relationships, for the Lebedev and rotated staggered grids for anisotropic, elastic finite-difference calculations. Comparing the computational costs of these two methods for equivalent dispersion errors, we conclude that the Lebedev grid is preferred. It has the added advantage that for models with common material symmetries, it can be decomposed into uncoupled subgrids, and only one of these grids must be stored. This has important implications for applications such as elastic reverse-time migration and full-waveform inversion.