Topographic effects observed in shadowed pixels in satellite imagery

For precise radiometric corrections of satellite imagery over rugged terrain, we have to evaluate various possible radiation and irradiation sources. In the satellite imagery with high sun elevation, however, the direct solar irradiance is too dominant to observe the minor sources. In this paper, we focus on the adjacent terrain irradiance and show its effect quantitatively on the shadowed pixels using Landsat TM image (band 5) with low sun elevation. Exact calculation of the effect is proposed and compared to the approximate methods.