Vibrational Spectral Line Detection in GIS Environment for Mineral Mapping Applications of Hyperspectral Data of the PRISMA Satellite

We develop a mathematical algorithm that calculates discrete spectral derivative of the hyperspectral data of the satellite mission PRISMA in a Geographic Information System (GIS) environment. Vibrational fingerprits of minerals appear in the reflectance spectra as local "dips" centered at a resonance wavelength that characterizes some classes of minerals. The algorithm is then applied twice to each spectrum in each image datacube: once on the descending slope of a known vibrational feature, and once on the ascending slope. The sum of the absolute value of the two derivatives, obtained from a total of several tens of hyperspectral channels, is then combined in a vibrational line intensity score, which is then used to build mineral abundance maps. We apply the method to a mountain area, mapping freshly exposed gneiss under molten glaciers (vibrational resonance at 2222 nm), and to volcanic islands mapping rhyolite deposits on shores (resonance at 2104 nm).