Initiated by Vidale (1988), several finite difference algorithms for calculating traveltimes have been developed (Van Trier and Symes, 1990; Podvin and Lecomte, 1991). These algorithms solve the eikonal equation as follows:

(7) |

Using the advantages of the existing algorithms, I have developed an adaptive finite difference scheme that is always stable and fully vectorizable (Zhang, 1991a). Further, I interpreted the finite difference method as local wavefront propagations through local ray tracing, and proposed a more accurate method that I call the local paraxial ray method (Zhang, 1991b).

12/18/1997