Topographic Correction of Sunny and Shady Slope in Different Division Methods Based on Slope-matching Model

By using geography, forestry resource survey, shadow formation principle, solar azimuth of acquisition time and solar zenith of acquisition time 5 different division methods of shade slope and sunny slope to calculate parameters for topographic correction of the Landsat5 TM images of Shangri-La and Gaoligong Mountain based on slope-matching model.From visual analysis, image perspectivethe reduced after correction, to some extent, to eliminate the impact of the terrain.From the mean of shady slope and sunny slope, the same mean of sunny slope and sunny before correction and corrected to illustrate that the topography effect had little effect on the sunny slope.The range of mean brightness difference between sunny and shady slopes of each band was minimum in the correction results of B divide which was the best.From the histograms, topographic effects reduced after correction, histogram of remote sensing images approximated normal distribution.B was the best according to the comparison of the histogram details.Based on the analysis of coefficient of variation, coefficient of variation of corrected images was smaller than before correction, the D had the smallest CV value at each band, which showed that the D was the best.Most of the topographic effect was removed after terrain correcting on image, The topographic effect had little effect on the sunny slope brightness, overcorrection existed after correcting results by slope-matching model, but the spectral characteristics maintained better for each band features of study area on the corrected images.Comparison of the corrected results in 5 kinds of shady and sunny slopes division method, the forestry resource survey in division of shady slope and sunny slope was the best, followed by solar zenith of acquisition time, solar azimuth of acquisition time, geography and topographic shadow formation principle.