基于最小分辨对比度准则 ,研究了天空背景下红外点目标的最大探测距离估计方法。首先 ,分析了红外波段大气辐射传输与衰减、对比度限制光电成像系统功率响应特性 ,建立了目标表观对比度模型 ,并推导出了由气溶胶消光系数和距离参量确定的探测距离方程。然后 ,对目标天空背景温差、发射率 ,气溶胶衰减系数 ,瞬时视场、对比度探测阈值以及辐射波长等参数作了详细讨论。最后 ,利用LOWTRAN7程序的典型大气模式数据 ,对红外点目标探测距离进行了数值模拟 Based on the minimum resolution contrast criterion, the method to estimate the maximum detection distance of infrared point targets under the sky background is studied. Firstly, the atmospheric radiation transmission and attenuation in the infrared band are analyzed. The contrast of the power response of the optoelectronic imaging system is limited by the contrast. A target apparent contrast ratio model is established and the detection distance equation determined by the aerosol extinction coefficient and distance parameter is deduced. Then, the parameters such as the background temperature difference, emissivity, aerosol attenuation coefficient, instantaneous field of view, contrast detection threshold and radiation wavelength are discussed in detail. Finally, using the typical atmospheric mode data of LOWTRAN7 program, the target detection distance of infrared point is numerically simulated