Improved topographic correction approach for radiation of remote sensing image

Remote sensing images of rugged areas are severely affected by the topographic effects. Usually, the effects can cause plenty of shades in the images and result in a high variation in the reflectance response for similar vegetation types. Accordingly, these effects will strongly affect the quality of vegetation classification. In general, the irradiance which a slope accepts contains three parts: the direct solar irradiance, the diffuse sky irradiance and the irradiance from adjacent terrain. But the area facing away from the sun cannot accept the direct solar irradiance. The C correction method which takes into accounts the effects of the atmosphere and adjacent terrain has become a popular method for topographic correction. But the C corrected image has a problem of overcorrection, especially in the area of high incidence angles, since this method is based on the empirical linear correlation between observed radiance and the cosine values of solar incidence angles. In this paper, an improved C correction method is proposed to reduce this error and improve the accuracy of classification.