目标表面发射率对红外辐射偏振特性的影响分析

偏振探测不仅可以获得目标的光谱、强度、偏振态以及空间几何形状等参数,还可以获得更丰富的目标信息,有利于改善对目标的探测和识别能力。红外辐射偏振成像是近年来发展起来的一种新的红外探测技术,主要通过目标与场景的红外辐射偏振特性差异进行目标探测与识别。但由于红外辐射偏振信息在传输过程中,其偏振态会受到传输介质的影响,而通常基于实验分析总结目标红外偏振特性的方法难以对偏振传输过程中的影响因素进行估计,也不能定量描述各相关参数对于红外偏振信息的影响。通过微面元理论的双向反射分布函数模型,建立了基于偏振双向反射分布函数的红外辐射偏振传输方程,推导分析了目标表面发射率对红外辐射偏振度的影响,结果表明:目标表面发射率对目标红外偏振度影响可以忽略;在理论分析基础上,有针对性的开展红外光谱偏振探测试验,试验数据分析与理论推导结论吻合。这表明:材料表面发射率的变化不影响目标表面的红外辐射偏振度。该研究成果有利于提高红外伪装探测的目标识别效率,可为进一步提高红外偏振成像系统的伪装目标探测提供新的途径和方法,如在伪装目标探测识别中,通过探测其表面的红外辐射偏振特性的改变实现伪装目标识别探测。

Influence Analysis of Target Surface Emissivity on Infrared Radiation Polarization Characteristics

Polarization imaging contains rich target parameters including spectrum,radiant intensity,polarization state,space geometry,etc .Polarization imaging can improve the target detection and recognition ability .The infrared polarization imaging is a new infrared detect technology in recent years .Infrared polarization imaging mainly aims to detect and identify the target with the difference of infrared radiation polarization characteristic between target and scene .But the state of polarization is affected by transmission medium in the transmission process of infrared radiation polarization information while the common method is to analyze the infrared radiation polarization characteristics of target that is not able to describe effects of all interrelated parameters and is difficult to estimate influence factors in the process of transmission .The equation of infrared polarized radiation is established through bidirectional reflectance distribution function based on micro-facet theory .And the mathematical model of the relationship between infrared radiation polarization degree and emissivity is derived in this paper .Result shows that the influence of target surface emissivity on the infrared degree can be ignored .On the basis of theoretical analysis,the infrared spectrum polarization imaging tests are unfolded,and the analysis of test data is consistent with the theoretical analysis .It is concluded that the correlation between the polarization degree of infrared and the emissivity of target surface can be neglected .The research production of this paper is conductive to increase of target detect efficiency,and it will provide new ways and means for camouflage target detect and identify .Therefore,the research production can be applied to detect and identify the camouflage target that is accomplished camouflage through change emissivity of camouflage target surface .