计算物理 ›› 2006, Vol. 23 ›› Issue (5): 604-608.

• 论文 • 上一篇    下一篇

波动方程深度偏移的局部裂步Fourier传播算子

陈生昌1, 马在田2, WU Ru-shan3   

  1. 1. 浙江大学地球科学系, 浙江 杭州 310027;
    2. 同济大学海洋地质重点实验室, 浙江 杭州 310027;
    3. Modeling and Imaging Laboratory, IGPP, University of California, Santa Cruz, CA 95064, USA
  • 收稿日期:2005-06-03 修回日期:2005-10-17 出版日期:2006-09-25 发布日期:2006-09-25
  • 作者简介:陈生昌(1965-),男,江西永新,副教授,博士,从事地震波传播与偏移成像及速度分析的方法理论及应用研究,浙江大学玉泉校区地球科学系310027.
  • 基金资助:
    国家高技术研究发展(863)计划(2003AA611020/01)资助项目

Local Split Step Fourier Propagator for Wave Equation Depth Migration

CHEN Sheng-chang1, MA Zai-tian2, WU Ru-shan3   

  1. 1. Department of Earth Sciences, Zhejiang University, Hangzhou 310027, China;
    2. Laboratory of Marine Geology, MOE, Tongji University, Shanghai 200092, China;
    3. Modeling and Imaging Laboratory, IGPP, University of California, Santa Cruz, CA 95064, USA
  • Received:2005-06-03 Revised:2005-10-17 Online:2006-09-25 Published:2006-09-25

摘要: 针对裂步Fourier传播算子在速度强横向变化介质中的不足,将算子的框架展开方法应用于Fourier传播算子中的相移算子,提出了一种波场传播的局部裂步Fourier传播算子,并把它应用于波动方程叠前深度偏移成像.这个局部裂步Fourier传播算子是由相空间(空间-波数)-频率域的相移算子和空间-频率域的窗口时移算子两部分组成.与波数-频率域的空间全局性相移算子不同,相空间-频率域的相移算子具有很好的空间局部性.通过在国际标准的SEG-EAGE二维盐丘模型的波动方程叠前深度偏移成像数值试验,证明局部Fourier传播算子不仅具有很好的稳定性,而且还特别适用于速度强横向变化介质.

关键词: 波动方程, 局部传播算子, 窗口Fourier框架, 展开, 叠前深度偏移

Abstract: A frame expansion method of operator is used to the phase shift operator of split-step Fourier propagator.A local split-step Fourier propagator for wavefield propagation is presented and used in a wave equation prestack depth migration.The local split-step Fourier propagator consists of a phase shift operator in phase-space-frequency domain and a windowed time shift operator in space-frequency domain.Different from the global phase shift operator in wavenumber-frequency domain,the phase shift operator in phase-space-frequency domain shows good space localization.A numerical test of wave equation prestack depth migration on the international standard SEG-EAGE 2D salt dome model shows that the local split-step Fourier propagator is stable and is applicable to the media with velocity strong lateral variation.

Key words: wave equation, local propagator, windowed Fourier frame, expansion, prestack depth migration

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