Mapping of the hydrothermal mineral alteration zones using aster data

摘要

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imagery provides a more subtle data to find mineralized alteration zones. Through the analysis of spectral characteristics of minerals that associate with hydrothermal alteration with the reference spectral from the USGS library, we combine the band ratio method and the Principal Component Analysis (PCA) to extract iron oxides and hydroxyl. The result shows that band4/band1 and band2/band1 highlights the iron oxides, band4/band6 and band5/band7 show Al-OH and Mg-OH of hydroxyl respectively. A case study of the presented method was applied to mineral alteration extraction in northeast of Sichuan province, China. Furthermore, Spectral feature fitting (SFF) was applied to test the mineral alteration points we obtained. It demonstrates that the combination of band ratio and PCA method is effective in extracting remote sensing minerals alteration.