低轨星座红外探测器对临近空间高超声速目标的可探测性分析  

Detectability Analysis of Low Earth Orbital Infrared Detectors for Near Space Hypersonic Targets

作　　者：田浩[1] 胡海飞[1] 蔡盛[1] 王久龙 徐伟[1] TIAN Hao;HU Haifei;CAI Sheng;WANG Jiulong;XU Wei(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033

出　　处：《红外技术》2024年第6期617-624,共8页Infrared Technology

基　　金：国家自然科学基金(62175234);吉林省优秀青年科技人才项目(应用技术类,20230508111RC);吉林省科技发展计划项目(20210203151SF)。

摘　　要：以STSS LEO红外探测平台为例,分析其对AGM-183A类空射式高超声速目标的可探测性。为了直观比较不同条件下目标的光电探测特性,将其量化为焦平面上输出信噪比超过阈值的像元数量。首先计算目标气动温度及光谱辐射强度,再利用探测器模型,计算在不同探测方向、距离和角度下,焦平面的信噪比峰值以及超过信噪比阈值的像元数量。分析结果表明,星下点模式下信噪比峰值最高(335),且超过信噪比阈值(6)的像元数最多(54×54),此像元数代表LEO星座对AGM-183A目标的最大可探测性。在临边探测模式下,给出目标可探测性随探测角度和目标温度的变化规律。结果表明,当目标温度接近800 K且探测方位角ψ小于10°(或大于170°)时,焦平面上超过信噪比阈值的像元数量为4×4,说明此时目标可探测性已经接近探测器的理论极限(3×3)。对比来看,温度的改变对目标可探测性的影响更为显著。在临边探测模式下,目标在飞行中段采用主动冷却手段降低表面气动温度以逃脱LEO探测的概率更高。从提高预警能力角度,要提高探测器在最不利角度对温度接近800 K目标的信噪比阈值(方位角ψ小于10°或大于170°时焦平面像元数量不低于8×8)。Using the infrared detector of the STSS LEO demo satellite as an example,the detectability of aerial hypersonic targets such as AGM-183A was analyzed.To visually compare the detectability of the targets under different conditions,the number of pixels on the focal plane with output signal-to-noise ratio(SNR)higher than a specified threshold was quantified.First,the aerodynamic temperature and spectral radiant energy of the hypersonic target were calculated.The infrared detector model was used to predict the peak value of the SNR and the number of responding pixels in the focal plane for specified detection distances and angles.The analysis results indicate that in the sub-satellite point detection mode,the SNR of the focal plane reaches the highest value(335),and the number of responding pixels with SNR higher than the threshold(6)reaches its maximum(54´54),representing the maximum detectability of the LEO detector for AGM-183A targets.In the edge detection mode,the variation in target detectability with detection angle and target temperature was calculated.The results show that,when the target temperature approaches 800 K and the detection azimuth angleψis less than 10°(or greater than 170°),the number of responding pixels on the focal plane reaches the lowest value of 4×4,indicating that the AGM-183A target detectability approaches the theoretical limit of the LEO detector(3×3).By comparison,changes in the target temperature have a more substantial impact on target detectability.In edge detection mode,the escape probability of the target is relatively high when the target uses active cooling to reduce its surface aerodynamic temperature to less than 800 K.From the perspective of improving early warning capability,the SNR threshold value of LEO detector focal plane should be increased for targets with surface temperatures approaching 800 K at the most unfavorable angles ofy(less than 10°or greater than 170°,with the minimum number of responding pixels in the focal plane no fewer than 8×8).

关 键 词：高超声速 低轨星座 红外探测器 信噪比 可探测性 

分 类 号：TN976[电子电信—信号与信息处理]