First results of the spectral characterisation of a salt flat in Europe: the Sal 'e Porcus salty pond

Sal ‘e Porcus is the largest natural salt flat in Europe, located in Sardinia (Italy) in the southwest region of the Mediterranean area. It spans over an area of more than 3.3 square kilometers. Its homogeneity and size characteristics make it a potentially suitable spot for use as a satellite sensor calibration/validation site. For this purpose, a campaign of spectral, mineralogical and LiDAR data acquisition has been organized in the framework of a dedicated International Remote Sensing Summer School in 2023. Furthermore, the study of this site has been funded by the Italian Spatial Agency through the Project: System for the “COnsOlidation of L2 products from the PRISMA-SG mission (COOL)”. New orbiting hyperspectral sensors such as ASI-PRISMA and EnMAP DLR and near future continuity missions (ASI-PRISMA SG, ESA CHIME) request ground reflectance spectra to rely on the remote sensed data. In this study, the first results of the study of the spectral and LiDAR data acquired on the site are described and discussed, focusing on two main outputs: i) the first release of the spectral library of the minerals of the salt flat; ii) the morphological setting of the surface. The collection of the spectra has been coupled with sediment samples for mineralogical characterization. During these campaigns, UAV-based LiDAR data were acquired. First results show that the topography of the surface changes from west to east, giving the idea of a geological control of this flat area. Moreover, first results of the spectral characterization of this surface using field, UAV and satellite data are discussed.