EVALUATION OF PRISMA HYPERSPECTRAL DATA FOR INLAND AND COASTAL WATER APPLICATIONS

This study aims to evaluate the consistency of remote sensing reflectance (Rrs) derived from PRISMA hyperspectral sensor in inland and coastal waters. The accuracy of PRISMA Level 2D errs products as distributed by Italian Space Agency and Rrs obtained from other atmospheric correction tools (e.g. ACOLITE, ATCOR) was assessed with above-water in situ reflectance from fixed autonomous radiometer systems and from spectral signature acquired in dedicated field campaign with hand-held spectroradiometer. For each site, in situ measurements of water reflectance were gathered with fixed position autonomous above-water radiometry systems, such as: AERONET-OC, PANTHYR, HYPERNETS and WISPStation. Match-ups analysis overall confirmed that the retrieved Rrs products are accurate and reliable, thus demonstrating the capability of PRISMA in providing adequate radiometric products over water bodies. A more specific analysis based on optical water types revealed higher accuracy in turbid and productive waters, while larger deviation with respect to in-situ data was found in clear waters and high-absorbing waters. Based on such findings the retrieval of biogeophysical parameters based on the bio-optical modelling inversion and adaptive band ratio algorithm was performed for several ecosystems. Examples cover mapping of water turbidity, phytoplankton pigments and total suspend matter concentrations as well as bottom depth and substrate types. In addition to report on the status of PRISMA for aquatic ecosystems applications and on its contribution to operational satellites, this study might be interesting for supporting the exploitation of analogues missions (e.g. EnMAP, CHIME and SBG) and provide a valuable contribution to the monitoring of waters ecosystem.