大气光谱光学厚度测量方法研究

为满足辐射校正场同步观测的需要,寻求一种能以简便的操作、较高的精度测量大气光谱光学厚度的观测方法是必要的。在合肥用地物光谱辐射计VF921-256和太阳辐射计DTF-1进行了为期几天的同步测量,经分析比较,发现VF921-256与DTF-1的测量结果之间存在1%~4%的相对偏差。这一偏差不但取决于光谱辐射计的测量误差,而且与太阳辐射计的标定误差也有一定关系。从VF921-256数据的Langley Plot拟合结果来看,其标准偏差小于0.03。因此,应用光谱辐射计测量大气光谱光学厚度的辐照度基法,可以用于辐射校正中对大气光谱光学厚度的同步测量。此外,我们利用光学厚度信息反演了气溶胶谱分布、臭氧和水汽的柱总量。

Measurement Method Research on the Atmospheric Spectral Optical Depth

In order to satisfy the requirement of the simultaneous measurements of the radiome- tric calibration, it is necessary to seek a simple, convenient and high accuracy method for measuring the spectral optical depth. Therefore, we had several days measurements by us- ing the Spectroradiometer VF921-256 and the solar radiometer DTF-1 simultaneously in Hefei city. Based on the results comparison, we found 1%~4% difference between them. The difference is not only due to the VF921-256, but may be attributed to the calibration error of DTF-1. It is shown from the fitting of measurements of VF921-256 that the stan- dard deviation is less than 0.03. So that the irradiance-based method of atmospheric opti- cal depth measurements can be used to simultaneously measure the optical depth during the radiometric calibration. Meanwhile, we also retrieved the atmospheric aerosol size dis- tribution, the ozone and water vapor colume content of Hefei city by using optical depth information.