We show the diffuse and specular reflection images of defective foams placed on iron plates, which are obtained by a bifocal active imaging system at 0.22 THz. Foam materials studied are extruded polystyrene boards and acetate copolymer boards with artificially embedded defects. In the field of view of approximately 50 × 90 cm 2 , the incident angle of the emitting and receiving cochannel system affects the reflected signal intensity and the imaging method. We build a light reflection model, which corrects the angle-dependent intensity behavior, to make the imaging results more intuitive. Experimental results show that large-angle imaging, which collects mainly diffuse reflection light, can be used to detect defects and is actually more suitable for detecting small defects than small-angle imaging, which mainly collects specular reflection light.

中文翻译：

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漫反射和镜面反射对使用 0.22 THz 双焦主动成像系统检测泡沫嵌入缺陷的影响


我们展示了放置在铁板上的有缺陷泡沫的漫反射和镜面反射图像，这些图像是通过 0.22 THz 的双焦主动成像系统获得的。研究的泡沫材料是具有人工嵌入缺陷的挤塑聚苯乙烯板和醋酸酯共聚物板。在约50×90 cm 2 的视场中，发射和接收同通道系统的入射角影响反射信号强度和成像方法。我们建立了一个光反射模型，它可以纠正角度相关的强度行为，使成像结果更加直观。实验结果表明，主要收集漫反射光的大角度成像可以用于检测缺陷，并且实际上比主要收集镜面反射光的小角度成像更适合检测小缺陷。