On parameterization in anisotropic media

Abstract The comparative analysis of parameterizations in anisotropic models of different symmetry is of importance to understand the nature of parameterization and potential problems. The critical issue is to distinguish between the large and small parameters. The main conclusion from this review is that the anisotropy parameters should be exactly (not approximately) defined from the phase velocity equations. The notation of normal moveout phase velocity helps to define the anisotropy parameters in low-symmetry anisotropic models. The magnitude of “naturally small” anisotropy parameters is not important. We also note that the tilt angles cannot be considered the small parameters.