Topographic Normalization in Rugged Terrain

Remote sensing of rugged terrain is hampered by topographic effects on spectral signatures. The purpose of this study was to attempt normalization of the topographic effect encountered when analyzing Landsat Thematic Mapper (TM) imagery in the Rocky Mountains. Two normalization techniques were performed on a subscene of a TM image of Rocky Mountain National Park. The first technique was a band ratio and the second was a backwards radiance correction transformation (BRCT) employing a Minnaert constant based on a non-Lambertian assumption. The results of this study indicated that application of the BRCT approach was the more successful technique for reducing topographic effects. Further, after conducting a homogeneity of variance test, the reduction of variances in spectral values between original and non-Lambertian normalized images was found to be statistically significant.