Mineral classification of soils using hyperspectral longwave infrared (LWIR) Ground-based data

Soil mineralogy is an important factor affecting chemical and physical processes in the soil. Most common minerals in soils-quartz, clay minerals and carbonates-present fundamental spectral features in the longwave infrared (LWIR) region. The current study presents a procedure for determining the soil mineralogy from the surface emissivity spectrum. Ground-based hyperspectral LWIR images of 90 Israeli soil samples were acquired with the Telops Hyper-Cam sensor, and the emissivity spectrum of each sample was calculated. Mineral-related emissivity features were identified and used to create indicants and indices to determine the content of quartz, clay minerals, and carbonates in the soil in a semi-quantitative manner-from more to less abundant minerals. The resultant mineral content was in good agreement with the mineralogy derived from chemical analyses.