Fast Sweeping Method with Adaptive Finite Difference Scheme Eikonal Solver
Many seismic applications require fast and accurate Eikonal equation solvers, such as Kirchhoff migration and tomography. One of the most stable and consistent methods is the Fast Sweeping Method, in which the Eikonal equation is numerically solved by the upwind finite difference scheme. Whenever finite difference is used, a plane wavefront is implicitly assumed. When waves propagate in inhomogeneous media, the assumption of plane wave front may be invalid. The errors generated in the spots on the bending wave front will propagate to the entire calculation domain, resulting in inaccurate propagation times. In this report, an adaptive finite difference scheme is introduced to improve the accuracy of the Eikonal solver in the Fast Sweeping Method.