可见光-近红外波段大气上行、下行辐射是辐射传输建模、成像模拟及大气校正关键的输入参数, 根据四流辐射传输理论给出了与二者相关大气参量的数值模型及计算方法, 针对Landsat 5 TM 6个波段建立了大气参量与水汽含量、能见度距离和太阳入射天顶角间的参数化模型, 在此基础上对各参量间敏感性进行了分析, 结果表明参数化模型具备较高精度。同时, 计算了各波段大气上行、下行漫射辐射值, 对二者在植被和裸土覆盖条件下的差异进行了定量分析。

Atmospheric upward and downward radiations in visible and near-infrared bands are the key input parameters for radiative transfer modeling, imaging simulation and atmospheric correction. This study presents the numeral models and computing methods of the atmospheric parameters which are related to the two parameters according to four-stream radiative transfer theory. Focusing on the six bands of Landsat 5 TM, the parametric models among atmospheric parameters, water vapor content, visibility distance and solar incidence zenith angle were designed, based on which the sensitivity of each parameter is analyzed. The results showed that the parametric models have higher precision. Meanwhile, the atmospheric upward and downward dif-fuse radiation of each band for TM remote sensing was calculated and the changes under the coverage of vegetation and bare soil were analyzed.