Seismic AVO and the inverse Hessian in precritical reflection full waveform inversion
Seismic AVO and the inverse Hessian in precritical reflection full waveform inversion
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DOI：
10.1093/gji/ggu291
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发表时间：
2014-11
影响因子：
2.8
通讯作者：
K. Innanen
中科院分区：
文献类型：
--
作者：
K. Innanen
本文分析了振幅随炮检距变化（AVO）信息在由临界前地震反射数据构造全波形反演（FWI）更新中所起的作用。频域FWI的混合连续-离散公式被发现可以方便地暴露参数串扰等问题以进行定量解释。两种类型的近似逆Hessian算子，不同之处在于保留非对角元素和忽略非对角元素，在此公式中可导出。第一种方法强调空间中不同参数之间的相关性，称为参数型近似。第二，强调空间分离的元素之间的相关性，被称为空间类型的近似。这两个近似是这样的，如果它们都是同时进行的，结果是只涉及海森的对角元素的更新。参数型逆Hessian近似似乎能够执行线性化AVO反演和逆散射方法避免串扰的数据操作。这是证实了在一个单一的声学边界的重建的第一次迭代的分析计算。参数型FWI更新，在这种特殊情况下，减少到反射系数与角度的线性混合，这是一致的直接AVO反演所产生的。在这个意义上，全逆Hessian中的参数型分量代表FWI中标准线性化AVO反演的推广。
We analyse the role played by amplitude-variation-with-offset (AVO) information in the construction of full waveform inversion (FWI) updates from pre-critical seismic reflection data. A mixed continuous-discrete formulation of frequency-domain FWI is found to conveniently expose issues such as parameter cross-talk to quantitative interpretation. Two types of approximate inverse Hessian operator, differing in which off-diagonal elements are retained and which are neglected, are derivable within this formulation. The first, which emphasizes correlations between different parameters collocated in space, is referred to as an approximation ofparameter-type. The second, which emphasizes correlations between spatially separated elements, is referred to as an approximation ofspace-type. The two approximations are such that, if they are both made simultaneously, the result is an update involving only the diagonal elements of the Hessian. The parameter-type inverse Hessian approximation appears to be capable of performing the kind of data manipulations through which linearized AVO-inversion and inverse scattering methods avoid cross-talk. This is confirmed with an analytic calculation of the first iteration in the reconstruction of a single acoustic boundary. The parameter-type FWI update, in this special case, reduces to linear admixtures of reflection coefficient versus angle which are consistent with those produced by direct AVO inversion. The parameter-type components in the full inverse Hessian represent, in this sense, the generalization of standard linearized AVO inversion within FWI.