热辐射环境下目标红外偏振特性分析

Analysis of Infrared Polarization Characteristics of Target in Thermal Radiation Environment

红外偏振成像技术具有提升目标识别率、辨别伪装目标等多重优势,但在复杂环境下目标的红外偏振特性容易受到干扰,从而出现错判和漏判的情况。为研究环境热辐射对目标红外偏振特性的影响,基于偏振双向反射分布函数推导了热源照射下目标表面红外线偏振度的解析模型。经过理论仿真及实验验证得出,环境热辐射会影响目标的红外偏振特性。当环境热辐射强度小于目标自发热辐射强度时,红外线偏振度与环境热辐射强度呈负相关,即环境热辐射强度越大,红外线偏振度越小。当环境热辐射强度大于目标自发热辐射强度时,红外线偏振度与环境热辐射强度呈正相关,即环境热辐射强度越大,红外线偏振度越大。上述结果表明,当目标受到外部热辐射影响时,红外线偏振度会发生规律性变化。

Infrared polarization imaging technology has many advantages, such as improving target recognition rate and identifying camouflage targets, but the infrared polarization characteristics of targets are easy to be disturbed in complex environment, resulting in misjudgment and omission. To study the influence of ambient thermal radiation on the infrared polarization characteristics of the targets, the analytical model for the degree of infrared linear polarization of target surface under heat source irradiation is derived based on the polarization bidirectional reflection distribution function. Theoretical simulation and experimental verification show that the ambient thermal radiation will affect the infrared polarization characteristics of the targets. When the intensity of ambient thermal radiation is smaller than that of the target spontaneous thermal radiation, the degree of infrared linear polarization is negatively correlated with the intensity of ambient thermal radiation, which means the greater the intensity of ambient thermal radiation, the smaller the degree of infrared linear polarization. When the intensity of ambient thermal radiation is greater than that of the target spontaneous thermal radiation, the degree of infrared linear polarization is positively correlated with the intensity of ambient thermal radiation, which means the greater the intensity of ambient thermal radiation, the greater the degree of infrared linear polarization. The above results indicate that the degree of infrared linear polarization will change regularly when the targets are affected by external thermal radiation.