实用化的二维波动方程叠前深度偏移

实用化的波动方程叠前深度偏移技术正在进一步发展完善之中。本文仅比较了其中四种具有代表性的方法，即分步傅里叶法(SSF)、傅里叶有限差分法(FFD)、广义屏法(GSP)和空间一频率域有限差分法(XWFD)。这四种方法的基本思路是：将速度场分裂为背景场和扰动场；背景场的波场延拓采用相移法实现；扰动场的偏移成像采用不同的实现方式，从而构成各种方法的不同特点。文中对四种方法相应的脉冲响应进行了测试分析，同时用Marmousi模型数据和实测地震数据作了偏移成像处理，计算结果比较理想。还将波动方程偏移结果与克希霍夫积分法偏移结果进行了对比，分析表明波动方程偏移成像结果在分辨率和对弱信号的成像能力等方面明显优于克希霍夫积分法。

Practical methods for 2-D wave equation prestack depth migration.

Practical methods for 2 D wave equation prestack depth migration are being further developed and completed.The paper only compared four representative methods,that is Split Step Fourier (SSF),Fourier Finite Difference (FFD),Generalized Screen Propagators (GSP) and Finite Difference in Space Frequency Domain (XWFD).All these methods have the following thinking: the velocity field is split into background field and disturbed field,the wavefield continuation of background field is completed by phase shift method and migrated imaging of disturbed field is fulfilled by different methods,so each method has his own characters.The paper tested and analyzed the pulse responses corresponding to four methods and migrated imaging processing was carried out by using Marmousi model and real seismic data separately at the same time,the calculated results are more ideal.The comparison of the results in these wave equation migration methods with those by Kirchhoff method is also carried out.The analyses showed the former is superior to the latter in resolution and imaging capacity for weak signal.