SIAM Journal on Imaging Sciences, Volume 14, Issue 1, Page 224-245, January 2021.
In this work, we have studied the asymptotic behavior of Green's function and the reciprocity relation of the far-field pattern in the stratified ocean waveguide. Moreover, two direct sampling methods (DSM) are proposed to determine the marine sources and scatterers from the far-field data. The direct approaches are fast, easy to implement, and computationally efficient since they involve only scalar product but no matrix inversion. In the numerical simulations, the DSM for the source is capable of identifying the sources from very few observation data, and the DSM for the scatterer can reconstruct the scatterers in different shapes, scales, types, and positions. The effectiveness and robustness of the novel methods are also demonstrated. Thus, the DSM can be viewed as simple and efficient numerical techniques for providing reliable initial approximate locations of the marine sources and scatterers for any existing more refined and advanced but computationally more demanding algorithms to recover the accurate physical profiles.

中文翻译：

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分层海洋波导中源和散射体的快速成像

SIAM影像科学杂志，第14卷，第1期，第224-245页，2021年1月。
在这项工作中，我们研究了格林函数的渐近行为和分层海洋波导中远场模式的互易关系。此外，提出了两种直接采样方法（DSM）来根据远场数据确定海洋源和散射体。由于直接方法仅涉及标量积而不涉及矩阵求逆，因此它们具有快速，易于实现和计算效率高的优点。在数值模拟中，源的DSM能够从很少的观测数据中识别源，而散射体的DSM可以以不同的形状，比例，类型和位置重建散射体。还证明了新方法的有效性和鲁棒性。因此，