Ore mineral discrimination using hyperspectral remote sensing-a field-based spectral analysis

Advanced Spaceborne Thermal Emission and Reflection Radiometer data of Salem District and field-based spectral observations using SVC HR 1024 spectral radiometer is used to make a clear discrimination of ore mineral deposits in parts of Salem District of Tamil Nadu. Spectral analyses, one of the most advanced techniques, are used to discriminate the magnesite deposits in the central northern part of Salem District. Different spectral processes were used in ore discrimination, which include the following: (1) atmospheric correction (FLAASH), (2) minimum noise fraction and (3) pixel purity index preparation which helps in discrimination by matching these purest pixels with field spectral observations. Spectral angle mapper method is used to produce score between 0 and 1, where the value of 1 makes a perfect match showing the exact ore deposit in the study area. Using these techniques, we were able to find two ore deposits in the study area, i.e. magnesite and lateritic bauxite, recording different scores related to their abundance.