Computer-enhanced multispectral remote sensing data: a useful tool for the geological mapping of Archean terrains in (semi)arid environments

Computer-based remote sensing techniques offer a unique chance to analyze and map the surface geology of remote arid environments in a relatively short time and at low costs. On the basis of multispectral Landsat TM 5, panchromatic SPOT and aerial image scanning data, the lithological and structural characteristics of a part of the Archean Pilbara granite-greenstone terrain (3.5-2.8 Ga) in Western Australia have been analyzed by using complex mathematical image enhancement techniques. The application of a sophisticated image processing software on an adequate PC (Dual Pentium II, 300 MHz) was necessary for the file management of the datasets, the calculation of TM data ratios (R), principal components (PC) and selected color composites (CC) which have been found more appropriate for the geological interpretation at a regional scale. These low resolution, but multispectral data (e.g. color composites) have been merged with high resolution panchromatic images to obtain new, high resolution images without loss of multispectral information. The interpretation of the new data contribute to a more detailed geological mapping of selected test sites which was studied during a field campaign in 1997. (C) 2000 Elsevier Science Ltd. All rights reserved.