地面目标与背景的红外辐射对比度特性

Infrared radiation contrast between ground target and background

红外系统对处于地面背景中的目标探测，很大程度上取决于目标本身与周围背景之间的红外辐射特征差异，即两者之间的辐射对比度。简要讨论了辐射对比度与目标发射率及目标背景温差的关系。分析了影响地面建筑物及水泥地面温度的各种因素，建立了基于一维有限差分法的计算温度的模型并利用MATLAB得以实现。计算了目标与背景在8～14μm波段上的红外辐射对比度。结果表明在不同情况下同一目标与背景的红外辐射对比度变化较大，不同方位墙面与背景的对比度具有不同的变化趋势。

Infrared detection of the ground target was greatly determined by the radiation contrast between the target and its background. The influence of emissivity of target and temperature difference on radiation contrast was briefly discussed. Factors on buildings and cement floor temperature were also analyzed. The model that computed temperature was built on the basis of finite difference method and realized by MATLAB. The target-background radiation contrast at 8-14 μm was calculated on the basis of the simulated temperature. It turns out that the radiation contrast of the same target and background changes significantly under different conditions. Variation trends of radiation contrast of the same target and background when observed in different azimuths are also presented.