We consider the problem of imaging extended reflectors in three-dimensional acoustic waveguides using a planar array that is parallel to the waveguide’s cross-section. Our data consist of the multiple-frequency array response matrix. To form an image, we back-propagate a projection of the data on the propagating modes in the waveguide. The projection operator is adequately defined for any array-aperture size and shape that cover fully or partially the waveguide cross-section. The properties of the imaging method are analyzed theoretically and its effectiveness is assessed by numerical experiments for scatterers and arrays of varying shape and size.

中文翻译：

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使用部分孔径数据在三维波导中成像

我们考虑使用平行于波导横截面的平面阵列对三维声波导中的扩展反射器进行成像的问题。我们的数据由多频阵列响应矩阵组成。为了形成图像，我们在波导中的传播模式上反向传播数据的投影。对于完全或部分覆盖波导横截面的任何阵列孔径尺寸和形状，投影算子都已充分定义。理论上分析了成像方法的特性，并通过数值实验评估了不同形状和大小的散射体和阵列的有效性。