Detection and imaging in a random medium: A matrix method to overcome multiple scattering and aberration
Detection and imaging in a random medium: A matrix method to overcome multiple scattering and aberration
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DOI：
10.1063/1.3200962
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发表时间：
2009-08-15
影响因子：
3.2
通讯作者：
Derode, Arnaud
中科院分区：
文献类型：
--
作者：
Aubry, Alexandre;Derode, Arnaud
我们提出了一种成像技术，特别适合于检测嵌入在强散射介质中的目标。经典的成像技术的基础上玻恩近似失败，在这种配置，因为多次散射回波和像差失真。我们考虑的实验设置使用可编程发射器/接收器阵列。目标被放置在散射介质后面。测量所有阵元之间的冲激响应并形成矩阵。该方法的核心是将目标的单次散射回波与多次散射背景分离。这是可能的，因为一个确定性的相干性沿着的反对角线的阵列响应矩阵，这是典型的单散射。一旦执行此操作，通过应用DORT方法（时间反演算子分解的法语首字母缩写）来实现目标检测。实验结果的情况下，宽带超声波约3 MHz。将125个元件的阵列放置在随机分布的钢棒（直径为0.8mm）的集合的前面。平板厚度是散射平均自由程的三倍，目标是一个直径为15 mm的较大钢柱，我们试图探测和定位。检测的质量进行评估，理论上基于随机矩阵理论，并被证明是显着优于与经典的成像方法所获得的。除了多重散射，该技术也被证明可以减少由异质层引起的像差。(C)2009年美国物理学会。[DOI：10.1063/1.3200962]
We present an imaging technique particularly suited to the detection of a target embedded in a strongly scattering medium. Classical imaging techniques based on the Born approximation fail in this kind of configuration because of multiply scattered echoes and aberration distortions. The experimental setup we consider uses an array of programmable transmitters/receivers. A target is placed behind a scattering medium. The impulse responses between all array elements are measured and form a matrix. The core of the method is to separate the single scattered echo of the target from the multiple scattering background. This is possible because of a deterministic coherence along the antidiagonals of the array response matrix, which is typical of single scattering. Once this operation is performed, target detection is achieved by applying the DORT method (French acronym for decomposition of the time reversal operator). Experimental results are presented in the case of wide-band ultrasonic waves around 3 MHz. A 125-element array is placed in front of a collection of randomly distributed steel rods (diameter of 0.8 mm). The slab thickness is three times the scattering mean free path. The target is a larger steel cylinder (diameter of 15 mm) that we try to detect and localize. The quality of detection is assessed theoretically based on random matrix theory and is shown to be significantly better than what is obtained with classical imaging methods. Aside from multiple scattering, the technique is also shown to reduce the aberrations induced by a heterogeneous layer. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3200962]