Finite-difference modelling of 2-D wave propagation in the vicinity of dipping interfaces: a comparison of anti-aliasing and equivalent medium approaches

Finite-difference (FD) modeling of seismic waves in the vicinity dipping interfaces gives rise to artifacts. Examples are phase and amplitude errors, as well staircase diffractions. Such errors can be reduced two general ways. In first approach, interface anti-aliased (i.e., with an step-function, or a lowpass filter). Alternatively, may replaced equivalent medium using Schoenberg \& Muir (SM) calculus orthorhombic averaging). We test these strategies acoustic, elastic isotropic, anisotropic settings. Computed FD solutions compared analytical solutions. find that acoustic media, anti-aliasing methods lead smallest errors. Conversely, SM provides best accuracy. The downside is it requires solver even model between isotropic materials. As result, computational cost increases when solvers. However, since coarser grid spacings used represent interfaces, effects (an expensive on grid) equal out. Hence, provide efficient means reduce also media.