Reflectance spectroscopy has been used by chemists for years and was “re-discovered” by the remote sensing discipline. Sensors such as Thematic Mapper on the Landsat V Satellite, the NASA-JPL aircraft based scanner AVIRIS (Airborne, Visible, InfraRed, Imaging Spectrometer), and various commercial aircraft systems all use information from the visible through short infrared bands for mapping, vegetation investigation, mineral exploration, and environmental monitoring. Geologists have recognized that this method has far reaching applications beyond remote sensing, especially in mineral exploration, core logging, alteration zone delineation, grade control, and lithology mapping.
Spectroscopy is particularly sensitive to the clay minerals and other alteration minerals such as carbonates, jarosites, iron oxides, hydroxides, alunites, pyrophyllite, serpentines, and chlorites. Therefore, the application to exploration, mine mapping and process control becomes apparent as these are usually pivotal minerals for defining a deposit type. This sensitivity is a function of the molecules present in the mineral phases, especially water, hydroxyls, and carbonate.
VIS-NIR-SWIR analyses have a wide range of applications - numerous CASE STUDIES can be viewed at our on-line training site: