导引头在3 Ma（1 Ma≈340.3 m/s）超音速飞行状态下，受到气动加热的光学窗口温度急剧上升，产生大量红外热辐射，干扰探测器的成像质量。为研究气动热辐射对导引头红外成像的影响：采用ANSYS软件对导引头进行三维建模、有限元网格划分及温度场仿真；采用普朗克黑体辐射公式与TracePro软件计算仿真得到的目标源与光学窗口在不同温度下产生的辐照度，建立信噪比模型，分析光学窗口温度及目标相对距离对导引头红外成像质量的影响。实验结果表明，导引头在2、11、20 km海拔高速飞行10 s后，红外成像系统信噪比分别下降了91.8%、50.1%、20.7%，信噪比的下降会严重影响红外系统成像质量，必须使用制冷措施冷却光学窗口以降低干扰。研究结果可为导引头的光学窗口及光学探测系统的设计提供数据参考，为克服气动热辐射干扰的相关研究提供理论依据。

In the supersonic flight state of 3 Ma (1 Ma≈340.3 m/s), the temperature of the optical window heated by aerodynamics rises sharply, resulting in a large amount of infrared thermal radiation, which interferes with the imaging quality of the detector. In order to study the influence of aerodynamic thermal radiation on infrared imaging, this paper used ANSYS software to perform 3D modeling, finite element meshing and temperature field simulation on the seeker model; by using Planck's blackbody radiation formula and TracePro software, the irradiance generated by the target source and the optical window at different temperatures were calculated and simulated, and the signal-to-noise ratio model was established to analyze the influence of the temperature of the optical window and the relative distance of the target on the infrared imaging quality of the seeker. The results showed that the signal-to-noise ratio of the infrared imaging system decreased by 91.8%, 50.1%, and 20.7%, respectively after the seeker flew at an altitude of 2 km, 11 km, and 20 km for 10 seconds. The decrease of signal-to-noise ratio will seriously affect the imaging quality of the infrared system, and the cooling measures must be used to cool the optical window for reducing the interference. This paper will provide data reference for the design of the optical window of the seeker and the optical detection system, and will provide theoretical basis for the research on overcoming the interference of aerodynamic heat radiation.