Lithological discrimination using aster images and geostatistical texture

The use of newly acquired ASTER data for lithological discrimination was evaluated. The variographical analysis was applied to several selected lithological units in order to analyze the spatial variability of these lithological units. Spectral classifications using 3 visible infrared (VNIR) bands, 6 shortwave infrared (SWIR) bands and their combination (9 bands) were performed and evaluated respectively in terms of overall classification accuracy. The texture was extracted from image by using variogram as a texture measure. The texture images, obtained by using different directions of lag distance, specified lag spacing and moving window, were combined with spectral bands for lithological discrimination. The results indicate that the inclusion of variogram texture in spectral classification considerably improves the overall classification accuracy. The effect of the direction of lag distance on variogram texture extraction and subsequential classification was discussed.