天基光谱探测特征波段的选择

Selection of feature bands based on space-based detection

为解决天基特征光谱最佳探测波段的选择问题，以11种导弹尾焰在2．5～5μm处的光谱作为研究对象，综合考虑导弹距地面高度、大气传输、云层辐射、大气辐射等因素，设计出一种从多目标角度考虑的波段选择算法，以目标相对具有强辐射为原则，根据距地面高到低、波段从多到少的顺序进行选择，可通过设定阈值来控制所选波段个数，文中所选波段的中心波长分别为2．99、3．06、3．12、4．6、4．62μm。根据光谱图像拟合规则拟合出包含目标的特征光谱图像，从信噪比的角度对特征光谱图像和全波长图像进行分析，结果表明，当目标达到一定高度后，特征光谱图像的信噪比远大于全波长图像。

The space-based missile early warning system has different detection effect in different bands, and it is very necessary to select the appropriate detection band. In this paper, 11 kinds of missile plume spectra were studied and analyzed in the 2-5 μm. Many influential factors were considered, such as the plume height from the ground, the atmosphere and cloud radiation, atmosphere attenuation, etc.. Principle of selection is relatively stronger radiation of target, distance of target-to-earth from high to low, wave bands from more to less. The number of bands can be controlled by setting the threshold. Finally, the paper selected bands at the center wavelength of 2.99, 3.06, 3.12, 4.6, 4.62 μm. According to matching rules to fit out image that contains the characteristics of the target spectral, and signal-to-noise ratio （SNR） was analyzed for characteristic spectral image and full wavelength image. The results show that when the target reaches a certain height, SNR of characteristic spectral image is higher than that of the whole wavelength image.