偏振成像在目标探测中的应用

Application of Polarimetric Imaging in Target Detection

针对偏振度编码成像在目标探测识别中的优点,本文分析了偏振探测的消偏振机理,以及表面散射和体散射对目标偏振度的影响。利用808nm半导体激光器照明,目标的后向散射光由卡塞格林望远镜接收,经过偏振分光棱镜成像在两个CCD上,通过一次测量获得偏振状态相互垂直的两幅图像,然后计算出目标的强度和偏振度,分别利用强度和偏振度编码成像。实验结果表明,在目标的反射率相近时,强度图像不能区分不同材料的目标,偏振度图像可以区分,融合强度和偏振度图像进行HSI伪彩色编码,可以达到目标探测、分类等目的。

To utilize the advantages of polarimetric imaging in target detection and recognition, the mechanism of depolarization in polarimetric detection and the influences of surface scattering and volume scattering on polarization degree are anayzed. Illuminated with 808 nm diode laser, the back scattered light of target is accepted by Cassegrain telescope. Two images are imaged on CCDs through Polarization beam splitter. Two orthogonal polarization state images can be obtained through once measurement, and then intensity and polarization degree can be calculated. Images coded with intensity and polarization degree are acquired. Experimental results show that intensity image can not distinguish targets when having similar albedo, whereas the polarization degree image can distinguish targets. Using HSI pseudocolor coding method to fuse the intensity and polarization images, the aim of target detection and recognition are achieved.