New era in regional geological mapping: multispectral satellites and advanced data processing


Ludovic Bigot, Effigis Geo-Solutions; Michel Rheault, Effigis Geo-Solutions; Ludovic Legros, Effigis Geo-Solutions

Multispectral satellite imagery enables high-precision predictive mapping for large territories around the world. Because multispectral optical satellites measure the electromagnetic signal in specific windows of solar radiation — usually in the visible and infrared light spectrums,  they offer the ability to identify a variety of minerals, including iron-oxides, iron-magnesium silicates, clays, micas, carbonates, sulfides and silica. The success of the NASA’s medium-resolution multispectral satellites, notably Landsat and ASTER, has recently been followed by the commissioning of the high-resolution multispectral satellite, WorldView-3 operated by DigitalGlobe. This satellite boasts well positioned spectral bands in the near and short-wave infrared windows that enable the identification of a wide and precise range of minerals, notably in hydrothermal alterations associated with mineralized systems. Effigis has developed an innovative approach that integrates the processing of WorldView-3 imagery with the analysis of available geological, geophysical and geochemical databases. The talk will emphasis on image processing from calibrating to mineral recognition. We will then demonstrate how the integration of classified images with upgraded both geophysical and geochemical data sets brings about a paradigm shift in the area of predictive geological mapping.