在分析实际大气环境参数的差异和目标-背景辐射强度的基础上，利用MODTRAN模式分析了东海、西北区域3.9 μm和9.2 μm波段的大气透射率和目标背景对比度的逐月分布特征；为了分析实际大气、气溶胶效应对目标-背景辐射传输的综合影响，结合局部地区月平均环境参数进一步探讨了上述两个区域内气溶胶对3.9 μm和9.2 μm波段的大气透射率和目标背景对比度分布的影响。结果表明，大气温度、水汽混合比等参数对大气透射率和目标背景对比度有影响，东海区域目标背景对比度比西北区域的小; 3.9 μm处两区域的目标背景对比度不仅比9.2 μm处的小，而且受到气溶胶的衰减作用比9.2 μm处的强，因此在目标识别中应优先考虑使用9.2 μm作为工作波段。

Based on the analysis of the difference among the actual atmospheric environment parameters and the target-background radiation intensity, the monthly distribution characteristics of atmospheric transmissivity and target-background contrast in east China sea area and northwest area at 3.9 μm and 9.2 μm are analyzed by the MODTRAN mode. In order to study the comprehensive influence of actual atmosphere and aerosol on target-background radiation transmission, a further research about the influence of aerosol effect on the distributions of atmospheric transmissivity and target-background contrast at 3.9 μm and 9.2 μm is carried out combined local region monthly average environmental parameters. The result shows that the atmospheric parameters of atmospheric temperature and water vapor mixing ratio have influence on the distributions of atmospheric transmissivity and target-background contrast. The target-background contrast in east China sea area is always lower than that in northwest area. The target-background contrast at 3.9 μm is not only lower than that of 9.2 μm in the two areas, but also suffers more aerosol attenuation. Therefore, the 9.2 μm is highly recommended as the working wavelength in the target identification.