CHIME requirements consolidation study: potential value-added products of the next Copernicus hyperspectral mission in "Agriculture & food security" and "Raw materials exploration"

In the framework of the Copernicus Programme, the user consultation process highlighted strong requirements in relation to both stability and continuity of products and services provision. Several of these requirements will be matched by the Next Generation (NG) of Sentinel missions (1 to 6 series), ensuring the continuity of initial observations and by the so-called High Priority Candidate Missions, including the hyperspectral mission. The study is based on the use of already available airborne and spaceborne data (including ASI mission PRISMA after the end of the commissioning phase) to simulate hyperspectral sensor configuration (spectral, spatial and temporal resolution). To select relevant variables (in accordance with the CHIME MAG variables), a composite index was used, taking into account the users' communities needs, the feasible layers retrievable in terms of biophysical product, and the CHIME mission unique contribution in terms of relevance in the product retrieval. The resulting scoring system identified a set of EO products suitable for CHIME. Ten products useful to map topsoil properties (soil organic carbon content, Soil texture), vegetation properties (LAI, canopy water content, Leaf and canopy pigment content, Leaf Mass/Area) and to characterize raw material compositions were highlighted. These products have been generated using state-of-the-art retrieval algorithms and exploiting the available airborne hyperspectral data from AVIRIS-NG, APEX and HyPlant-DUAL sensors, acquired in 2018 over a test site near Grosseto (Italy) and Cuprite (Nevada, USA). The final step of the study quantifies the accuracy performance of different products and tests the resulting outputs in comparison and in synergy with the corresponding products from the multispectral Sentinel-2 mission.