改进的Malkmus带模式晴空大气透射率计算方法

摘要

The Malkmus band model has been widely used in remote sensing and climate studies. However, its accuracy is not high. To solve this problem, a modified Malkmus band model was proposed by introducing a correction item. The HITRAN (High-resolution TRANsmission) 2008 database and the atmospheric models provided by the Air Force Geophysics Laboratory (AFGL) were used to calculate the molecular transmittances. By fitting the calculated transmittances to those by MODTRAN (MODerate resolution atmospheric TRANsmission) package with the least-squares method, the fitting coefficients of the correction item were obtained under different atmosphere models. The experimental results show that the root mean square errors (RMSE) of the modified model are significantly less than that of the traditional Malkmus band model by 1-2 orders of magnitude. In addition, the modified method is suitable for different atmospheric models and molecules.%Malkmus带模式在气候研究以及遥感应用中具有较高的应用价值，然而其计算精度不高。针对该问题，引入修正量对Malkmus模型进行改进。实验采用HITRAN2008谱线数据和美国空军地球物理实验室（AFGL）提供的6种大气模式计算垂直路径大气分子的透射率数据。在不同的大气模式下，以MODTRAN计算结果为参考标准，利用最小二乘拟合得到修正量并将其用于大气透射率补偿。相对于传统Malkmus模型，改进模型的透射率精度提高了1~2个数量级。结果表明，本方法不仅能有效地提高模型计算精度，而且适用于不同的大气模式和大气分子。