Huygens wavefront tracing: A robust alternative to ray tracing

Traveltime computation is widely used in seismic modeling, imaging and velocity analysis. The two most commonly used methods are ray tracingand numerical solutions to the eikonal equation. Eikonal solvers are fast and robust, but are limited to computing only the first arrival traveltimes. Ray tracing can compute multiple arrivals, but lacks the robustness of eikonal solvers. Here, we propose a robust and complete method of traveltime computation. It is based on a system of partial differentialequations equivalent to the eikonal equation, but formulated in the ray coordinate system. We use a first-order discretization scheme that is interpreted very simply in terms of Huygens’ principle. The method has proved to be a robust alternative to conventional ray tracing, while being faster and having a better ability to penetrate shadow zones.