超音速飞行环境中光学头罩热辐射建模与分析

Modeling and analysis of infrared radiation from the dome flying at supersonic speed

在超音速飞行中,红外光学头罩由于空气摩擦而加热,产生红外辐射从而形成热背景,挤占探测器动态范围,降低探测信噪比,严重时会使探测器饱和,丧失探测能力。文中对此进行了分析,并建立了光学头罩热辐射及其影响分析模型,包括光学头罩辐射、辐射传输和探测器响应等部分,可分别计算光学头罩辐射亮度,光线追迹和探测器响应。最后,利用所建立的模型分析了探测器接收的热背景辐射与头罩温度的变化关系以及高速飞行过程中辐射随时间的变化趋势。研究结果可以用于评估高速飞行环境下头罩热辐射对系统性能的影响。

In supersonic flight,the infrared dome is heated by friction with the air,and it will create an infrared flux that can degrade signal-clutter ratio,even drive the detector into saturation.In this paper,an analytic model of the infrared radiation from heated dome was built based on ray tracing method.The model was organized into three modules,such as the radiation module,the optics module and the detector module,which were used for computing the radiation luminance of infrared dome,calculating the ray trace and getting the output of detector.Finally,an example was given to analyze the radiant power received by the detector,and the radiant power profiles were plotted as a function of dome temperature and flight time.The results can be used for assessing the performance degradation as a result of aerodynamic heating of the dome flying at high speed.