Atmospheric Correction of SPOT5 Land Surface Imagery

Abstract

High spatial resolution satellite images are playing the more and more important role in real-time monitoring on earth surface conditions. But haze and cloud reduce those application capabilities, especially in south of China. Thus, atmospheric correction is necessary for extracting quantitatively information from high spatial resolution satellite images. SPOT5 imagery is selected as the data source. In terms of multi-spectral imagery, in order to remove hazy regions and get the surface reflectance imagery, an improved homomorphic filter is combined into the matching mean reflectance in both hazy/clear regions method. Based on band characteristic of SPOT5, visible bands take part in classifying after haze removal using the improved homomorphic filter in process. Both aerosol optical depth and surface reflectance images are retrieved using MOTRAN 4.0. What' more, in terms of panchromatic imagery, authors use MOTRAN 4.0 remove atmospheric effect by means of the retrieved aerosol optical depth. The two retrieved surface reflectance images are both obviously better than original images. When more bands of SPOT5 take part in classifying, it can improve the accuracy of clusters in both hazy & clear regions, so it is helpful to make up the disadvantages of mean reflectance matching method in both hazy/clear regions. Meanwhile, the method in paper can be used other high spatial resolution satellite images.