Introduction

The goal of obtaining efficient and robust multiple-arrival traveltimes has yet to be accomplished in practice. The typical traveltime methods-eikonal solvers, ray tracing and wavefront construction-either only compute the first-arrival traveltimes (eikonal solvers) or are expensive and not always robust in regions of high velocity variation (ray tracing and wavefront construction). However, Huygens wavefront tracing (HWT), introduced in a previous paper Sava and Fomel (1998), does offer a robust and very efficient method of computing multiple-arrival traveltimes.

This paper presents my extension of Huygens wavefront tracing to three dimensions. I start by briefly reviewing the theory, then I discuss how to handle the triplications of the wavefronts and present one 2-D and two 3-D examples. I continue with a brief comparison to other traveltime methods, and end with conclusions and possible directions for future work.