Up to now, the search for mineral resources has been a complex and therefore cost-intensive undertaking with great entrepreneurial risk. A new, satellite-based procedure called ReSens+ (Resource Sensing) can contribute significantly to increasing the efficiency and quality of searching and prospecting for these resources. It was developed at the GFZ German Research Centre for Geosciences and will be presented at the international mining trade fair EXPONOR on May 15 to 19 in Chile and at the DMT mining forum on June 1 and 2 in Berlin. ReSens+ is the result of research included in the EnMAP satellite mission (Environmental Mapping and Analysis Program) and is available as a service immediately.
“The process displays geographical distribution and the content of iron, rare earth elements, carbonates and clays in deposits of mineral resources – namely in arid and semi-arid areas of any size and in every uncovered area of the world,” says Dr. Christian Rogass from the GFZ section Remote Sensing and Project Head for ReSens+. “Under optimal conditions, it yields results reliably and precisely within a few days. Conventional exploration techniques can then be used in a more targeted manner.”
ReSens+ is based on a specially developed analysis model that produces highly accurate maps from freely accessible satellite images with information on elements, mineral distributions and distinctive deviations, so-called exploration anomalies. In order to do this, the spectral composition of the sunlight is compared with the radiation that is reflected from the Earth’s surface and has been measured by the satellite. Each unknown pixel spectrum that is normed in this way is compared with the spectra of known minerals or elements. The fact that this ‘spectral fingerprint’ is unique means that the procedure can be used anywhere in the world in order to track accumulations of certain elements and minerals on the Earth’s surface.
“The unprecedented quality of the data and results is based on several pillars,” says Rogass. “This includes multi-temporal satellite observations, a patent-pending procedure for spectral analysis and our cross-sectional knowledge of geology and spectroscopy.” The procedure is also already used for spectroscopic analyses via drone and plane flights and of rock faces, drill cores and hand specimens. Thus there is a basis for further services. “Our objective is to support mining from prospecting, exploration and extraction to raw material transformation and stockpile monitoring in order to do justice to the social challenge of treating resources in an environmentally and efficient manner already at the source.”
GFZ already uses the underlying technology of imaging spectroscopy using multispectral and hyperspectral satellite sensors routinely and successfully for agricultural and forestry purposes. Current research projects aim to allow the detection of landmines and ammunition remnants in order to develop previously restricted living spaces following clearing.
Figure in a >>printable resolution
Figure caption: The ReSense+ procedure, developed at the GFZ, shows a distinctive mineral and element distribution at the surface using the example of the El Abra copper mine (Chile; figure: C. Rogaß, GFZ).