THE APPLICATION OF SCS+C METHODS FOR TOPOGRAPHIC RADIATION CORRECTION

Abstract

As irradiance depends on slope and aspect,the remote sensing image in rugged areas is severely affected by the topographic effects.Topographic correction based on sun-canopy-sensor(SCS) geometry is more appropriate than terrain-based corrections in forest areas because SCS preserves the geotropic nature of trees(vertical growth) regardless of terrain,view,and illumination angles.However,in some terrain orientations,SCS might encounter the overcorrection problem similar to other simple photometric functions.To solve this problem,Scott proposes a new SCS+C correction that accounts for diffused atmospheric irradiance based on the C-correction.The SCS+C method was tested by a Landsat 5 image in a rugged area of Beijing.The results show that SCS+C can provide improved corrections compared with the SCS and three other photometric approaches(cosine,C,SCS),remove topographic effects successfully and restore the land-surface information in shadow areas effectively.