声波虚谱法模拟与偏移及其吸收边界探讨

Modeling and Migration of Acoustic Equation by Pseudospectral Method

利用傅里叶变换求取空间微商的方法通常叫虚谱法。本文介绍了在二维介质中用虚谱法进行全声波波动方程数值模拟与偏移的原理和实现方法,讨论了虚谱模拟中的吸收边界及其改进形式,具体计算了点脉冲和两个理论地质模型的偏移结果,分析表明虚谱法在模拟与偏移中是行之有效的,而且精度高于有限差分法。

It is usually called pseudospectral (PS)method to obtain a spacial derivative by the Fourier transformation. A principle for using acoustic equation modeling and migration in 2-D media with the PS method is introduced and the implementation thereof is given. Absorbing boundaries are discussed. Specific calculations are made of the migration effects of a point impulse and two simple models. The final results show that the PS method is more efficient and precise than the finite difference method(FD).