基于6S模型的环境星CCD数据大气校正

Atmospheric Correction of HJ-1 CCD Data Based on 6S Model

应用6S辐射传输模型建立查找表,对环境与减灾小卫星CCD数据进行大气校正。结果表明:校正后的图像更加清晰,对比度增强;与实测光谱对比,处理后的环境星数据可以更真实地反映地物反射特征,消除了NDVI信号在大气传输过程中的衰减效应,更好地复原了地表植被覆盖的真实状况。通过讨论,提出对于HJ-1-A的CCD数据,可以考虑通过同星搭载的高光谱传感器进行气溶胶光学厚度反演;对于HJ-1-B的CCD数据,可以采用对比方法反演气溶胶光学厚度,进而作为模型的输入来提高大气校正精度,以及考虑地表二向性反射现象来提高大气校正精度。

This paper examined the atmospheric correction of HJ-1 CCD data using an approach of look-up table created from 6S model to acquire land surface reflectance.The result shows that the image after the correction is much better than the original one,indicating that the attenuation of NDVI can be rectified to improve the application of HJ-1 CCD data for remote sensing of vegetation.Aerosol optical depth is required for the correction.In order to ensure the precision of the correction,the authors suggest that the required aerosol optical depth can be retrieved from the hyper-spectral data on the same platform as the HJ-1-A data.As for the HJ-1-B data,the aerosol optical depth can be estimated by using the contrast reduction method with consideration of the land surface BRDF.