传统的太赫兹时域光谱成像通过寻找成像目标的单一特征参数来进行成像,这种方法有很大的局限性,无法灵活对比各种特征参数成像的优劣,很难对成像目标形成明显的对比。为此,针对耐高温复合材料胶接缺陷的太赫兹无损检测,提出一种新的图像增强方式——多特征参数成像,该方法可以通过改变单一特征参数在成像通道的权重,改善整体的成像效果。基于多特征参数成像方法,实现了耐高温复合材料上胶层0.05 mm厚度,下胶层0.15 mm厚度预置脱粘缺陷识别,相比于单特征参数成像方法,图像对比度提高了2倍。

Traditional terahertz time-domain spectral imaging is performed by finding a single characteristic parameter of the imaging target. This method has great limitations,it cannot flexibly compare the advantages and disadvantages of imaging with various characteristic parameters, and it is difficult to form a clear contrast to imaging target. This paper proposes a new imaging method, multi-feature parameter imaging, for terahertz non-destructive detection of high temperature composite material bonding defects. This method can improve the overall imaging effect by changing the weight of a single characteristic parameter in the imaging channel. Based on the multi-feature parameter imaging method, the thickness of the upper adhesive layer of 0.05 mm and the lower adhesive layer of 0.15 mm are preset for debonding defect recognition. Compared with the single-feature parameter imaging method, the image contrast is increased by 2 times.