红外预警卫星最佳探测波段分析

Analysis of optimum detective wavebands for infrared early-warning satellite

为解决红外预警卫星在近中红外的最佳探测波段问题,采用建模仿真的方法获得了2～5μm波段范围内不同高度条件下火箭尾焰目标的红外辐射光谱特性,利用MODTRAN软件包计算了典型大气条件下同样波段范围内不同高度处的大气透过率和地球/大气背景红外辐射光谱特性,在此基础上计算了目标背景之间的对比度。通过分析目标背景对比度的变化规律可知:随着飞行高度的增加,目标背景对比度会先增大后减小,但无论在什么飞行高度,2.63～2.83μm和4.18～4.50μm波段的目标背景对比度都较大,比较适合目标探测,并且这两波段还具有更加精细的波段结构,实际应用中可根据探测需求选择更小的波段范围并确定相应的中心波长。

To find out the optimum detective wavebands in the SW and MW infrared region for infrared early-warning satellite, the infrared radiation spectral characteristics of rocket plume targets at various altitudes were obtained by simulating and modeling. The atmospheric transmittances and the infrared radiation spectral characteristics of geo-atmospheric backgrounds with typical atmospheric conditions at various altitudes were calculated using MODTRAN software at 2～5 μm waveband. Then the contrast between the target and the background was gained. By analyzing the variety of the contrast, it is found that the target-background contrasts increase firstly, then decrease with increasing flight height. But no matter what height, the contrasts remain high at wavelength of 2.63～2.83 μm and 4.18～4.50 μm, which is applicable for target detection. Besides, each of these two bands demonstrates more better structures, which makes it available to choose corresponding applicational wavelength in more narrow band.