临边观测下火箭喷焰红外辐射可探测性分析

Detectability Analysis of Rocket Plume Infrared Radiation Under Limb Observation

本文针对空基平台大气层内、天基平台水平、短路径和长路径四种临边观测体制下,分析不同高度上火箭喷焰的点源红外信号在MWIR(3.70-4.80μm)和LWIR(7.70-9.50μm)波段大气窗口区的可探测性。采用视在光线法(LOS)求解火箭喷焰点源本征辐射,并考虑大气透过率、背景计算在不同平台下目标与背景的辐射对比度CR。在以探测器瞬时视场为1 km×1 km,最低的辐射对比度C(R)=0.02为界限以分析点源目标的可探测性。结果表明四种探测方式在MWIR波段的辐射对比度基本上大于0.02;在LWIR波段,空基平台和天基平台短路径探测在的辐射对比度在<70 km大于0.02,长路径探测在<40 km的高度范围内大于0.02,天基平台水平探测在各个高度上均大于0.02;MWIR波段的可探测性能要优于LWIR波段。

In this paper,the detectability of atmospheric window in MWIR(3.70~4.80μm)and LWIR(7.70~9.50μm)band is studied for the point source infrared signals of rocket plume at different altitudes under four limb detection systems of the air-based detection,space-based horizontal detection,short-path detection,and long-path detection.The line-of-sight(LOS)method is used to solve the intrinsic radiation of the rocket plume point source,and the radiation contrast CR between the target and the background under different detection platforms is calculated considering the atmospheric transmittance and the background.The detector's instantaneous field of view is1 km×1 km,and the lowest radiation contrast ratio C_(R)=0.02 is utilized as the limit to analyze the detectability of the point source target.The results show that the radiation contrast of the four detection modes in the MWIR band is basically greater than 0.02.In the LWIR band,the radiation contrast of the air-based platform and the space-based platform for short-path detection is greater than 0.02 at<70 km,and the radiation contrast of the space-based platform for long-path detection greater than 0.02 at<40 km,and the radiation contrast of the space-based platform horizontal detection is greater than 0.02 at all heights.The detectability performance of the MWIR band is better than that of the LWIR band.