Smoothing operators for waveform tomographic imaging
Smoothing operators for waveform tomographic imaging
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DOI：
10.1190/1.1443380
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发表时间：
1993-11
期刊：
影响因子：
3.3
通讯作者：
S. Cardimona;J. Garmany
中科院分区：
文献类型：
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作者：
S. Cardimona;J. Garmany
声波波形数据的弗雷歇导数相对于慢度模型中的变化的空间-时间域中的解析核由波形散射的积分方程的玻恩近似解给出。在这个正问题的解决方案中的预处理算子，它可以包含先验信息和近似解，是成像问题中的平滑算子，慢度模型的非线性反演的第一次迭代。一些预处理算子的抛物波方程的解决方案确定，然后用于创建新的灵敏度函数，保留适当的特性，真正的弗雷歇内核在向前计算。新的灵敏度函数定义了近源、近接收器和远场内核，以及表现出振幅衰减的内核，这些内核产生与菲涅耳区大小成比例的射线垂直灵敏度。一个合成井间成像实验的样本计算
The analytic kernel in the space‐time domain for the Frechet derivative of acoustic waveform data with respect to changes in the slowness model is given by the Born approximation solution to the integral equation of waveform scattering. Preconditioning operators in the solution of this forward problem, which may incorporate a priori information and approximate solutions, are smoothing operators in the imaging problem, the first iteration of a nonlinear inversion for the slowness model. Some preconditioning operators are determined for solutions to the parabolic wave equation, and then used to create new sensitivity functions that retain appropriate characteristics of the true Frechet kernel in forward calculations. The new sensitivity functions define near‐source, near‐receiver and far‐field kernels, as well as kernels that exhibit an amplitude decay off the ray yielding ray‐perpendicular sensitivity that scales with the Fresnel zone size. A sample calculation from a synthetic cross‐well imaging experimen...