Finite-difference anisotropic traveltimes and raypaths

Marco A. Perez, John C. Bancroft

Traveltimes are calculated using finite-difference solutions to the eikonal equation. The scheme presented computes traveltimes based on a finite-difference approximation to the eikonal equation for transversely isotropic (TI) and isotropic media. The method expands along wavefronts, following minimum traveltimes to honor causality. A technique for determining raypaths using the reciprocity principle is also presented. The proposed methods are valid for weak to moderate levels of anisotropy as defined by Thomsen's parameters.