模拟地震波传播的大网格快速差分算法

LARGE GRID FAST DIFFERENCE METHOD MODELLING PROPAGATION OF SEISMIC WAVES

大网格快速差分法以最佳差分算子为理论基础，使群速度误差最小．这种方法的量大特点是空间网格可以取得很大，只要算子半长度取成４－６，每最短波长取３个空间网格点就可得到精度很高的弹性波场模拟结果．理论计算表明本方法比传统有限差分格式的计算速度至少快一个数量级，比伪谱法快３－５倍．

A fast finite difference method of large spatial grids,based on optimized difference operator,makes error of group velocity be the least.If only the halflength of the operator is taken 4to 6,this technique offers accurate wavefield results on the grid of 3 grid points per shorttest wavelength.In the case of 2 dimension media this fast difference method is at least one magnitude more efficient than conventional finite difference scheme and 3 to 5 times more efficient than the pseudospectral method.