Probability characteristics of thermal infrared radiation for anisotropic spheres

Abstract

针对红外探测制导和检测等研究的热点问题, 探讨了目标红外辐射的方向性对红外探测的影响.以各向异性等温球体为研究对象, 建立从目标到探测器敏感面阵的红外传输整体模型.以能量概率密度分布函数为基础, 构造敏感面上单元格的能量描述方法.采用蒙特卡洛法, 计算单元格的红外信号强度, 分析红外小目标的方向辐射特性对探测敏感面上能量分布的影响.结果表明, 当目标表面半球方向发射率一定时, 提高法向发射率可显著增强目标中心所在像元的红外信号强度, 增大目标像元间红外信号对比度.;In accordance with the hot issues of infrared detection and guidance, an IR transmission process from target to sensitive array was established to explore the IR signatures of an anisotropic-isothermal sphere model. The energy probability density distribution function was employed to describe the energy intensity levels of sensitive array units. The energy distributions of detector units were abtained with the aid of the Monte Carlo Method. The relationship between target directional IR radiation characteristics and energy distributions on the sensitive array was revealed. It indicates that in the case of the equal hemispherical emissivity of far-field small targets, increasing the emissivity in the near-normal direction can appreciably enhance the IR intensity of the image-center unit and improve the IR intensity contrast among the image units.