Polarity-consistent excitation amplitude imaging condition for elastic reverse time migration
Polarity-consistent excitation amplitude imaging condition for elastic reverse time migration
复制标题
弹性逆时偏移极性一致激励振幅成像条件
DOI：
10.1088/1742-2132/12/1/33
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发表时间：
2015-02
影响因子：
1.4
通讯作者：
Xiaoran Chen
中科院分区：
文献类型：
--
作者：
Qizhen Du;Mingqiang Zhang;Xufei Gong;Xiaoran Chen
成像条件不仅影响逆时偏移（RTM）的计算效率和存储成本，而且决定最终偏移图像的质量。本文将保幅高效激励振幅成像条件的思想从声学RTM扩展到弹性RTM。对于弹性RTM，在源波场正向建模时保存分离出的纵波的最大幅度和各网格点对应的成像时间，然后将后向传播的接收器波场的分离出的纵波和横波除以预先计算的满足成像时间的各网格点的纵波，得到PP和PS图像。然而，当需要堆叠图像时，PS图像的极性反转会造成相消干扰。为了解决这个问题，我们将激励幅度成像条件与炮域极性反转校正方法相结合，提出了极性一致的激励幅度成像条件。然后我们给出了该成像条件在弹性RTM中的详细实现过程。通过与相对稳定且振幅保持良好的源归一化互相关成像条件进行对比，从振幅保持特性、复杂结构成像能力、存储成本和计算效率等方面证明了所提出的成像条件的可行性和有效性。考虑到效率和图像质量之间的平衡，极性一致的激励幅度成像条件可以成为弹性RTM的良好选择。
Imaging conditions can not only affect the computational efficiency and storage cost of reverse time migration (RTM) but determine the quality of the final migrated images. This paper extends the idea of the well amplitude-preserved and highly-efficient excitation amplitude imaging condition from acoustic RTM to elastic RTM. For elastic RTM, the maximum amplitude of the separated P-wave and the corresponding image time of each grid point are saved during the forward modeling of the source wavefield and then PP and PS images are obtained by dividing the separated P- and S-waves of the backward-propagated receiver wavefield by the precomputed P-waves at each grid point that satisfies the image time. However, polarity reversals of the PS image will cause destructive interference when the stacked image is needed. In order to solve this problem, we propose the polarity-consistent excitation amplitude imaging condition by combining the excitation amplitude imaging condition with a shot-domain polarity reversal correction method. Then we provide the detailed realization process of this imaging condition in elastic RTM. By utilizing the relatively stable and well amplitude-preserved source-normalized cross-correlation imaging condition as a comparison, we testify to the feasibility and validity of the proposed imaging condition in the aspects of amplitude preservation property, imaging capability of complex structures, storage cost and computational efficiency. Considering the balance between the efficiency and image quality, the polarity-consistent excitation amplitude imaging condition can be a good choice for elastic RTM.
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DOI：
--
发表时间：
2013
期刊：
--
影响因子：
--
作者：
Xue Dongchuan
通讯作者：
Xue Dongchuan
影响因子：
3
作者：
P. Micikevicius
通讯作者：
P. Micikevicius
影响因子：
3.3
作者：
Y. Duan;P. Sava
通讯作者：
Y. Duan;P. Sava
影响因子：
3.3
作者：
D. Loewenthal;I. Mufti
通讯作者：
D. Loewenthal;I. Mufti
影响因子：
3.3
作者：
W. Symes
通讯作者：
W. Symes