Regular grids travel time calculation - a practical Huygens wavefront expansion approach

Summary We present a practical regular grid wave traveltime calculation that is based on Huygens wavefront expansion and grid traveltime mapping. Wavefront expansion is carried out by finite difference approximations to the equations that are equivalent to the Eikonal equation with a fixed time interval. Mapping traveltime from wavefront to regular grids is based on a dynamic ray tracing paraxial approximation.