Combining Diving and Reflected Waves for Velocity Model Building by Waveform Inversion
Combining Diving and Reflected Waves for Velocity Model Building by Waveform Inversion
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DOI：
10.3997/2214-4609.20141094
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发表时间：
2014-06
期刊：
影响因子：
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通讯作者：
W. Zhou;R. Brossier;S. Operto;J. Virieux
中科院分区：
文献类型：
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作者：
W. Zhou;R. Brossier;S. Operto;J. Virieux
全波形反演（FWI）的目的是从全波场重建高分辨率的地下模型，其中包括潜水波，亚临界反射和短排列反射。FWI的大多数成功应用都是由潜水波和亚临界反射所携带的信息驱动的，以建立速度结构的长到中波长。替代方法最近已被重新审视，以检索这个长波长的内容，从短传播的反射，只使用一些先验知识的反射率。本研究提出了一种统一的形式主义，其目的是更新低波数的速度模型的联合反演的潜水波和全反射波场。该方法依赖于平滑速度宏模型和反射率之间的显式尺度分离，其被假设为已知的，以及短展反射和广角到达之间的显式数据分离（即，潜水波和亚临界反射）。简单的分层模型和合成Valhall模型上的应用程序显示如何强调在所有深度的地下低波数含量，只保持传输波路径产生的全波场的梯度FWI。
Full Waveform Inversion (FWI) aims to reconstruct high-resolution subsurface models from the full wavefield, which includes diving waves, subcritical reflections and short-spread reflections. Most of the successful applications of FWI have been driven by the information carried out by diving waves and subcritical reflections to build the long-to-intermediate wavelengths of the velocity structure. Alternative approaches have been recently revisited to retrieve this long-wavelength content from short-spread reflections only using some prior knowledge of the reflectivity. The present study presents a unified formalism, which aims to update the low wavenumbers of the velocity model by joint inversion of the diving waves and the full reflected wavefield. The method relies on an explicit scale separation between a smooth velocity macromodel and reflectivity, which is assumed to be known, and an explicit data separation between the short-spread reflections and the wide-angle arrivals (i.e., diving waves and subcritical reflections). Applications on simple layered models and a synthetic Valhall model show how the low-wavenumber content of the subsurface is emphasized at all depths by keeping only the transmission wavepaths generated by full wavefields in the gradient of FWI.