Millimeter wave-based material inspection methods are capable of providing 3-D-tomographic images of composite materials with a sufficient resolution to detect, localize, and classify critical defects. The nondestructive and noncontact-based measurement methods' potential can only be utilized with a complete understanding of the signals propagation behavior. Such that the relevant signal processing is tailored to the respective application. A core challenge of these systems remains clutter mitigation. Due to the composite materials' structure, a significant component of the received signal is corrupted by internal reflections, manifesting as clutter. For this purpose, a variety of different clutter mitigation methods, which include: normalization, moving average and moving median filter, entropy-based filtering, time gating, spatial filtering, and singular value decomposition, are investigated. These methods are applied to tomographic data of glass fiber reinforced plastic components, acquired via a W-band imaging system.

中文翻译：

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层析材料检测的杂波缓解方法概述


基于毫米波的材料检测方法能够提供具有足够分辨率的复合材料 3D 断层扫描图像，以检测、定位和分类关键缺陷。只有完全了解信号传播行为，才能发挥非破坏性和非接触式测量方法的潜力。以便相关信号处理适合相应的应用。这些系统的核心挑战仍然是减少杂波。由于复合材料的结构，接收信号的一个重要组成部分会被内部反射破坏，表现为杂波。为此，研究了各种不同的杂波抑制方法，包括：归一化、移动平均和移动中值滤波器、基于熵的滤波、时间选通、空间滤波和奇异值分解。这些方法适用于通过 W 波段成像系统获取的玻璃纤维增​​强塑料部件的断层扫描数据。