具吸收边界条件的波动方程偏移的拟合分解方法

本文讨论了在波动方程偏移问题中构造吸收边界条件方程的原则,并提出了求解具有吸收边界条件的偏移问题的一种新方法——矩阵拟合分解方法。这一方法的特点在于所构造的差分方程的拟合分解格式可以通过三点褶积和正、反递归被快速求解。 通过合成记录和野外实际资料的偏移对这一方法进行了验证。理论分析和实际计算都表明,该方法可以有效地消除来自网格边界的人工反射,减少了因增加边道或其他方法所需要的辅助计算而带来的计算工作量,提高了计算效率,因而是一种有效方法。

FITTING DECOMPOSITION METHOD FOR WAVE EQUATION MIGRATION WITH ABSORBING BOUNDARY CONDITIONS

In this paper a fitting decomposition method is proposed and the principles for construe- ting equations which characterize the absorbing boundary conditions is discussed for wave equation migration. The advantage of this method is that the difference schemes obtained in this way can be solved by the efficient algorithm of three point convolution and forward-backward recurrence.This method is tested with synthetic section and field data. Both the numerical results and the theoretical analyses show that the boundary reflections are suppressed efficiently and the computational efforts are reduced in comparison with conventional padding boundary traces.