中文摘要：

本文利用Modtran4．0模式比较系统地研究了不同强度（以地面能见度表示）和不同类型气溶胶情况下，晴空和各种云所形成的天空红外亮温n（Infrared Brightness Temperature）随地面观测天顶角的变化，从中发现利用Tb观测来遥感云底高度CBH（Cloud Base Height）的可行性，以及定量分析气溶胶层的影响．并且根据模拟计算结果，推出了由地面温度和湿度来计算晴天和不同CBH的中低云天天顶Tb的统计算式，以及由观测Tb和地表温、湿值反演CBH的方法．从模式计算和试验的初步结果可以看出：对于低云和中云，地基观测的Tb对CBH的变化有相当的敏感性，因此可以用于CBH的反演．地面气溶胶（能见度和气溶胶类型）对天空背景Tb有明显的影响，必须加以订正．但由于其影响对不同天顶角的贡献有一定的规律性，因此有可能得到较好的订正．

英文摘要：

We attempt to study the feasibility of cloud base height （CBH） remote sensing by ground-based sky thermal infrared brightness temperature （Tb） observation and quantitative effects of the aerosol layer on it. Using the Modtran4.0 model simulation, the variations of Tb with zenith angle of observation for different types of aerosol and different visibilities under clear and cloudy sky conditions were systematically investigated. Based on the simulated results, the statistic equations for clear and cloudy sky Tb calculation were obtained respectively, and then a preliminary method of CBH estimation was developed. The results of simulation and preliminary experiments show that for low and middle clouds, the sky Tb observed on the ground is very sensitive to the variation of CBH, therefore it can be used to estimate CBH. The influence of aerosol （visibilities and aerosol types） above the ground on the sky Tb cannot be neglected, which must be corrected. Because the regularity of aerosol＇ s influence on Tb with different zenith angles is fairly clear, it can be corrected well.