本文基于高温红外窗口热辐射红外成像探测器干扰机理，开展高温红外窗口成像分析、仿真与实验验证研究工作.根据流体仿真计算获得的高温窗口温度及实验测得的窗口发射率、吸收率等参数，开展窗口热辐射计算；建立了光学窗口介质内部辐射传输路径和强度计算模型，并给出了窗口辐射出射模型以及相应红外成像模型；基于光学追迹方法，把窗口热辐射成像的计算问题转换成了光学计算问题；设计了一种基于高温蓝宝石红外窗口的加热实验，对红外成像仿真结果进行了检验.通过仿真结果与窗口加热实验结果对照，将基于模型分析获取图像与实验结果图像作差，得到的平均每个像素误差值为0.45；实验发现在窗口约773 K条件下，设计的中波红外成像系统的信噪比、对比度分别降低到原来三分之一左右，而整个红外成像系统NETD值由原来的约52 mK上升到了954 mK.本文提出的窗口热辐射分析方法可以有效估计窗口热辐射对中波红外成像的影响，设计的实验对成像系统的指标验证有较好的用途，同时对红外成像系统波段细化优选和成像参数调整，降低图像退化程度，都有着重要的指导意义.%During supersonic flight, the heat radiation of aero-craft optical window has negative effect on infrared imaging performance. A computational model of radiance transmit route and radiation intensity was built in the paper. And the paper also gave the radiation emission model and infrared imaging model. The problem of heat radiance imaging was transform to the problem of optical computa-tion. The simulation results showed that method proposed by the paper was effective to analysis the heat window radiation problem. An heating sapphire window experiment is designed to validate the simulation result. By subtraction between the deduced image based on model and experiment image, it is found that average error for each pixel is about 0.45. By analysis of experiment results, the infrared image contrast degree and Signal-to-Noise was reduced to about one third of the original ones. And the NETD of infrared system with heating window rose from 52 mK to 954 mK. The heating window radiation analysis model presented by the paper can effectively estimate aero-thermal effects on mid-wave infrared imaging system. The designed experiment developed a effective way to verify imaging system performance. And it is also much meaningful for optimal infrared spectral band selection, imaging parameter adjustment and the hot dome radiation suppression to reduce the image degradation.
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