Seismic travel time tomography using Fresnel volumes and a Fast Marching Eikonal Solver

Traditional seismic travel time tomography based on ray-tracing, methods assumes that the wave's frequency is infinite. As a consequence, only the medium located along the ray path has an impact on the wave propagation. Ray-tracing methods suffer from several problems (Vidale, 1988). For heterogeneous media, there are many rays that can connect a source and a receiver and it is easy to miss the shortest path and expensive to test every path between these two points. There may also exist shadow zones, due to aliasing or velocity distributions. Wave guides and caustics can also trick the ray-tracing methods.