在低照度下,光学偏振特性能够增强伪装目标的图像信息,但物体的空间偏振特性表现复杂,会随探测条件的不同而发生变化.为了探究撒布地雷目标空间偏振特性分布规律,设计并搭建基于多角度测量架的光学偏振观测系统,对几款典型撒布地雷和常见地面背景进行多入射角度、多观测角度偏振成像实验.实验结果显示,所测各类目标的偏振度均在一定程度上受不同观测方位的影响,其中地雷目标偏振度变化较大,而沙子的偏振度受观测方位的影响较小;在入射光的镜面反射方位附近,地雷目标与地面背景的偏振度差值达到最大,并且适当增大入射天顶角有助于提高撒布地雷目标与地面背景的环境分辨能力.
Optical polarization features can enhance the image information of camouflaged targets under low illumination; however, the spatial polarization characteristics of objects are complex and change under different detection conditions. To investigate the distribution law of the spatial polarization characteristics of scattered mine targets, an optical polarization observation system based on a multi-angle measuring frame was designed and constructed, and polarization imaging experiments with multiple incidence and observation angles were conducted on several typical mines and common ground backgrounds. The experimental results show that the polarization of all types of measured targets is affected by different observation directions to a certain extent. In particular, the polarization of landmine targets varies greatly with the observation direction, and the polarization of sand is less affected by the observation direction. Near the specular reflection direction of the incident light, the polarization difference between landmine targets and the ground background reaches the maximum, and appropriately increasing the incident zenith angle can help improve the discrimination between the dispersal of landmine targets and the background environment. Therefore, the ability to distinguish between a dispersed mine target and the ground background was improved by appropriately increasing the incident zenith angle.
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