Imaging spectroscopy is an effective tool to detect, monitor, and manage key abiotic natural resources including minerals, soils, and fossil fuels, which are largely non-renewable. Current research in hyperspectral remote sensing focuses on the assessment of mineral deposits, the detection of oil spills, the derivation of soil properties, and the evaluation and monitoring of soil quality (e.g., water and carbon storage, acidification and erosion).
Minerals, or more specifically ore minerals, contain economically valuable elements (mainly metals), which are essential to modern industry and, therefore, the development of society. The constantly changing demand of ores and the criticality to the producing industry causes perennial re-evaluations of existing occurrences, deposits and mines, and the global detection and validation of new deposits. EnMAP data can identify, characterize, and map many VNIR–SWIR active minerals on the Earth’s surface. The following main scientific tasks are related to geological exploration:
- Development of versatile algorithms for the identification and mapping of listed minerals under complex mixing conditions;
- Analysis of the capability of hyperspectral data for the detection of rare earth minerals based on different globally distributed sites;
- Development of new algorithms and models for non-linear, weighted unmixing and mineral quantification approaches; and
- Analysis of the capability of EnMAP data in new fronts in geology and mineral exploration including (but not limited to) lithium and rare earth element resources.
- Investigation of the effects of mineral-induced stress on the spectral signature of dense vegetation canopies to establish a link between vegetation stress and specific minerals.
- Spectral unmixing and removal of the effect of vegetation on spectral signatures of minerals.
Soil is a fundamental and irreplaceable natural resource, which is largely non-renewable. Soils are complex dynamic systems, which are formed and developed through the combined effects of climate and biotic activities, modified by topography. Soil provides a multitude of land-based ecosystem goods and services supporting and regulating life on the planet. It carries out several key environmental functions that are essential for human subsistence, such as food, fiber and timber production, water storage and redistribution, pollutant filtering and carbon storage. EnMAP data has considerable potential to characterize the pedosphere by identifying soil properties, changes over time, and relationships between soil degradation and canopy spectroscopy. The following main scientific tasks are related to digital soil mapping:
- Retrieval of soil properties, such as organic matter and iron content, particle size distribution, clay mineralogy, water content, soil contamination, cation exchange capacity and calcium carbonate content to analyze status and changes of soils;
- Improvement of methodologies and algorithms for the extraction of key soil parameters based on remote sensing spectral signal with emphasis on prediction accuracy and influence of spatial scale;
- Quantitative estimation of the influence of surface parameters in bare and semi-bare areas (such as water content, vegetation cover, surface roughness) on the spectral signature of soils and on the retrieval of soil properties;
- Analysis of the contribution of global soil databases to calibrate the remote sensing-based soil condition indices against reference samples; and
- Monitoring of the state of soils and development of spatio-temporal maps of soil properties.