临近空间对地探测目标与背景红外特性研究

红外辐射特性是红外探测系统进行目标识别的主要依据。基于辐射传输原理，面向临近空间对地探测目标与背景的红外特性进行研究。利用全球大气廓线反映全球大气状况先验知识，设计了一套临近空间对地探测红外特性研究的辐射传输仿真方案。利用MODTRAN模型进行仿真，量化临近空间对地探测目标与背景的红外特性差异，分析传感器最优透过率波段以及红外辐射特性的影响因素。结果表明，大气透过率以及目标与背景的红外辐射差异随着临近空间传感器高度的增加而减小，且与大气状况密切相关；得出了传感器在3~14 μm范围内的最优透过率波段；季节、大气能见度与传感器观测角度对目标与背景的亮温差异造成的影响不可忽略。

Infrared Characteristics of Ground Targets and Background Observed from Near Space

Infrared radiation characteristics are the basis for target recognition in infrared detection systems. Based on the principle of radiation transmission, the infrared characteristics of the target and background in near space were studied. Using the global atmospheric profile to reflect the prior knowledge of the global atmospheric conditions, a set of radiation transmission simulation schemes were designed to study the infrared characteristics of ground targets detected from near space. The MODTRAN model was used for the simulations. The difference between the ground target and background detected in near space was quantified, and we analyzed the optimal transmission band of the sensor as well as the influencing factors of infrared radiation characteristics. The results show that the atmospheric transmittance and infrared radiation difference between the target and background decrease with an increase in the height of sensor and are closely related to the atmospheric conditions. The optimal transmission of the sensor in the range of 3-14μm was obtained; however, the influence of the season, atmospheric visibility, and sensor view zenith angle on the brightness temperature difference between the target and the background cannot be ignored.