Advances in hyperspectral processing for province- and continental- wide mineral mapping

Comprehensive mapping of the mineral composition within North Queensland, Australia was recently undertaken using 25,000 km² of airborne hyperspectral imagery. High spatial resolution, web-accessible, seamless, accurate maps of mineral abundances and physicochemistries, were delivered as part of a Queensland Geological Survey initiative. This required the development of pre-processing and mineral information extraction strategies that could be applied across a large number of individual flight lines within a diverse range of environments. This study demonstrated the successful use of spectral indices to target diagnostic reflectance absorption features associated with mineral abundances, composition and variations associated with crystalline or water bonding states. A multi-level series of masks, in a logical sequence, were applied to reduce possible ambiguities within image products. A new technique was also developed to compensate for variable vegetation cover, enabling the extraction of predominantly geological information (e.g. soil, outcrop, colluvium).