Unwrapped phase inversion with an exponential damping
Unwrapped phase inversion with an exponential damping
复制标题
DOI：
10.1190/geo2014-0498.1
复制
发表时间：
2015-07
期刊：
影响因子：
3.3
通讯作者：
Yunseok Choi;T. Alkhalifah
中科院分区：
文献类型：
--
作者：
Yunseok Choi;T. Alkhalifah
摘要当数据频率不够低时，全波形反演（FWI）存在相位包裹（周期跳变）问题。除非我们获得一个良好的初速度模型，否则在FWI中，相位包裹问题会导致对应于局部最小值的结果，通常与真实解相去甚远，尤其是在深度处。因此，我们开发了一种基于空间域未包裹相位的反演算法，并且我们还使用指数阻尼来减轻与反射相关的非线性。我们构建二维相位残差图，其中通常包含包裹不连续，特别是当模型复杂且频率高时。然后我们展开相位映射并删除这些基于周期的跳跃。但是，如果相图中有多个残差，则展开过程将变得非常复杂。我们对波场施加强指数阻尼，以消除相位图中的大部分残留物，从而使展开过程变得简单。我们终于揭开了…
ABSTRACTFull-waveform inversion (FWI) suffers from the phase wrapping (cycle skipping) problem when the frequency of data is not low enough. Unless we obtain a good initial velocity model, the phase wrapping problem in FWI causes a result corresponding to a local minimum, usually far away from the true solution, especially at depth. Thus, we have developed an inversion algorithm based on a space-domain unwrapped phase, and we also used exponential damping to mitigate the nonlinearity associated with the reflections. We construct the 2D phase residual map, which usually contains the wrapping discontinuities, especially if the model is complex and the frequency is high. We then unwrap the phase map and remove these cycle-based jumps. However, if the phase map has several residues, the unwrapping process becomes very complicated. We apply a strong exponential damping to the wavefield to eliminate much of the residues in the phase map, thus making the unwrapping process simple. We finally invert the unwrapped...