Mapping Forward Modeling Method Based on Dual-variable Grid

Seismic wave forward modeling is very important in seismic exploration research, and the result of conventional finite difference scheme maybe inaccurate when simulating surface topography, since it can generate ladder-shaped ‘burr’ in discrete process. With the idea of transforming the irregular border into the horizontal border, mapping method can deal with this problem. In this paper, we apply dual variable grid idea into mapping scheme. The new combining technique can not only convert the surface topography to horizontal surface, but also can use different grid size in different regions, and use locally variable time step to match with the variable grid spacing. Simulating tests of several models show that the method proposed in the paper is accuracy as well as computationally efficient.