Alteration minerals extracting methods in Da Xing´anling, using ASTER imagery

With the advent of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), a 14-bands multi-spectral sensor operating onboard the Earth Observation System (EOS)-Terra satellite, the availability of spectral information in the shortwave infrared (SWIR) and thermal infrared (TIR) portion of the electromagnetic spectrum has been greatly increased than that on Landsat ETM+. In this paper, two methods, Principle Component Analysis (PCA) and Spectral Angle Mapper (SAM), was chosen to extract mineral alteration from remote sensing image, and compare their results with ASTER image. The work area, named Da Xing´anling, is located in north-east Inner Mongolia, China. From the research results, the authors draw the conclusions as following: ASTER data has great advantages on extracting mineral alteration information; Spectral Angle Mapper can effectively and rapidly locate the hydrothermal alteration, but can not distinguish each mineral; Principle Component Analysis can extract five common minerals from ASTER image, but need more time running in the whole process.