采用杂波模型进行天基目标红外探测波段的选择

Band selection for space-based infrared target detection using background clutter model

为了及时发现导弹目标,美国国防支援计划(DSP)系统采用了大气吸收波段进行探测。本文对该系统的波段设置及其选择方法进行了探索性研究,提出了一种基于背景杂波模型的波段选择方法。推导了简化的场景辐射参数表达形式,建立了场景空间杂波辐射模型,分析了中短波红外吸收波段内背景杂波辐射的主要影响因素,给出了综合信噪比解析式。然后,在可能的目标辐射特性与背景杂波水平内选择出最佳工作波段,使得探测系统对辐射特性相似的一类目标的综合探测性能达到最佳。最后,通过算例说明了该方法的有效性。计算分析表明,系统最佳探测波段与场景的杂波辐射水平以及目标的辐射特征密切相关。在不同的杂波水平下,对两种发动机喷焰的目标探测时,DSP的最佳工作波段为2.73～2.85μm与4.2～4.43μm。

In order to detect missile targets as early as possible, atmospheric absorption bands are used in the U. S Defense Support Program （DSP）. To explore the band settings and their selection methods for the DSP,a new method to choose the optimal detection bands based on a background clutter model is proposed. The simplified parametric expression for a scene radiation is deduced,＂ and then the spatial clutter model is established. The main factors impacting the clutter radiance are analyzed in absorption infrared wavebands,and the Synthetic Signal-to-noise Ratio（SSNR） is given in an analytic form. Finally, the optimal bands are chosen in all the possible scene clutter levels and target radiation characteristics, which provides the best system performance for detecting the same kinds of targets with the similar radiation characteristics under different clutter levels. The validity of the method is illustrated by examples. Calculation and analysis results indicate that the optimal detection bands are dependent on the scene clutter level and target radiation characteristics. For detection two different engine plumes, the optimal bands for DSP are 2.73--2.85 μm and 4.2--4.43 μm.