各向异性发射球体小目标热红外特性研究  

Thermal infrared characteristics of small spherical objects with anisotropic emission behavior

作　　者：黄勇[1] 崔雪[1] 

机构地区：[1]北京航空航天大学航空科学与工程学院,北京100191

出　　处：《科学通报》2014年第22期2223-2228,共6页Chinese Science Bulletin

基　　金：国家自然科学基金(51376016);高等学校博士学科点专项科研基金(20121102110015)资助

摘　　要：通过建立球体目标探测的随机概率模型,研究了各向异性发射体的热红外特性.运用蒙特卡洛法模拟采样成像,并将探测面阵单元格在积分时间内统计得到能量份额均值定义为灰度值,生成辐射灰度图.通过灰度图定量地表征了目标各向异性热辐射特性对红外信号的影响.结果表明,对于远场小目标,将辐射方向调控在近法向小辐射角范围内,即提高发射体表面材料法向发射率,可增强目标最亮像点信号强度,扩大"像"区域的能量对比度,在红外图像上表现为能量更加集中的信号点.This paper establishes a stochastic probability model for spherical object detection to investigate the thermal infrared （IR） characteristics of anisotropic emitters. The Monte Carlo method is used to simulate the image sampling process. The mean energy portion of the detector unit during the integration time is quantified as the gray level of the unit, and the gray level image, formed by combining the gray levels of all the detector units, can qualitatively illustrate the effects of the anisotropic emission patterns of the target surface on the target IR signatures. It is found that, for a farfield small spherical object, by confining the emission direction in a narrow angular range near the normal, i.e., by increasing the normal emissivity of the object surface materials, it is possible to strengthen the energy density of the brightest pixel and enhance the energy density contrast among the detector pixels. This results in a signal with a higher degree of energy concentration in the gray level image.

关 键 词：红外辐射 红外特性 角度分配 能量份额 灰度值 

分 类 号：O434.3[机械工程—光学工程]