Marmousi模型单炮叠前深度偏移的广义相位屏法及其并行实现

Single-shot prestack depth migration for Marmousi model and its parallel implementation using generalized phase-screen method

中国科学院计算数学与科学工程计算研究所科学与工程计算国家重点实验室,北京100080

Institute of Computational mathematics and Scientific Engineering Computing,Academia Sinica,Beijing 100080

叠前深度偏移是解决复杂构造成像的重要方法,单炮叠前深度偏移具有最高的精度。本文针对Marmousi复杂构造模型,用广义相位屏法进行了单炮叠前深度偏移,并与裂步法和傅里叶有限差分法的偏移结果作了比较。计算用MPI并行算法实现。数值计算表明,广义相位屏法的精度比裂步法高,与傅里叶有限差分法的精度相当,而其计算量要小于傅里叶有限差分法。由于并行算法缩短了计算时间,使得该方法用于实际资料处理成为可能。

Prestack depth migration is an important method for imaging geologically complex structures. Single shot prestack depth migration is of best precision. In the paper, we use generalized phase screen method to implement the single shot prestack depth migration for Marmousi model and we also compared results from splitting step Fourier (SSF) method and Fourier finite difference method (FFD). The calculation is carried out by MPI parallel algorithm. Numerical results show that the precision of the generalized phase screen method is better than that of SSF and can match with that of FFD while its computation amount is less than that of FFD. Considering the time saved by the parallel algorithm, it is possible to use the generalized phase screen method to process field data.