Hui Wang, Chen Shouqian, Zhang Wang, Dang Fanyang, Ju Lin, Xu Xianmei, Fan Zhigang
Opt Express. 2020 Mar 2;28(5):6172-6187. doi: 10.1364/OE.373020.
The imaging quality of the aerodynamically heated optical dome was evaluated under the comprehensive influence of aero-optical transmission effect and aero-thermal radiation effect. The ray propagating algorithm based on the fourth order Runge-Kutta method was used to trace the target ray and the thermal radiation ray of the optical dome. Three imaging quality evaluation parameters were proposed to evaluate aero-optical effect: Modulation transfer function (MTF), irradiance, peak signal-to-noise ratio (PSNR) of distorted images. The results show that: as the flight speed increased, the MTF decreased observably compared with the diffraction-limit MTF, the irradiance on the photosensitive surface of the detector increased gradually, and the distorted imaging quality under the influence of the comprehensive aero-optical effect gradually deteriorated. However, as the thickness of the optical dome increased, the MTF decreased sharply and the irradiance decreased gradually, that indicated the aero-optical transmission effect was reinforced and the aero-thermal radiation effect was weakened. The imaging quality improved with thickness increasing. The influence of aero-thermal radiation effect on the PSNR of the image was more serious than that of the aero-optical transmission effect.
在气动光学传输效应和气动热辐射效应的综合影响下，对气动加热光学头罩的成像质量进行了评估。采用基于四阶龙格 - 库塔方法的光线传播算法来追踪光学头罩的目标光线和热辐射光线。提出了三个成像质量评估参数来评估气动光学效应：调制传递函数（MTF）、辐照度、畸变图像的峰值信噪比（PSNR）。结果表明：随着飞行速度的增加，与衍射极限MTF相比，MTF明显下降，探测器光敏面上的辐照度逐渐增加，在综合气动光学效应影响下的畸变成像质量逐渐变差。然而，随着光学头罩厚度的增加，MTF急剧下降且辐照度逐渐降低，这表明气动光学传输效应增强而气动热辐射效应减弱。成像质量随厚度增加而提高。气动热辐射效应对图像PSNR的影响比气动光学传输效应更严重。
