Assessment of PRISMA water reflectance using autonomous hyperspectral radiometry

Hyperspectral remote sensing reflectance (Rrs) derived from PRISMA in the visible and infrared range was evaluated for two inland coastal water sites using above-water situ measurements autonomous hyper- multispectral radiometer systems. We compared Level 2D (L2D) surface reflectance, a standard product distributed by Italian Space Agency (ASI), as well outputs ACOLITE/DSF, now adapted processing of imagery. Near-coincident Sentinel-3 OLCI (S3/OLCI) observations were also it is frequent data source applications, with strong calibration validation record. In optically diverse Italy, equipped fixed hyperspectral systems, used: REmote Sensing Trasimeno lake Observatory (RESTO), positioned shallow turbid Central Acqua Alta Oceanographic Tower (AAOT), located 15 km offshore lagoon Venice Adriatic Sea, which characterised clear to moderately waters. 20 images available match-up analysis across both sites. Good performance L2D found RESTO, lowest relative (Mean Absolute Percentage Difference, MAPD < 25%) absolute errors (Bias 0.002) bands between 500 680 nm, similar ACOLITE. The median interquartile ranges spectral angle (SA 8°) denoted more shape RESTO data, indicating pigment absorption retrievals should be possible. ACOLITE showed better statistical at AAOT L2D, providing R 2 > 0.5, Bias 0.0015 35%, 470 580 i.e. highest reflectances. addition SWIR based sun-glint correction default atmospheric implemented further improved AAOT, lower uncertainties closer similarity measurements, suggesting that glint able best reproduce AAOT. good results Rrs retrieval our study sites, hence demonstrated use aquatic ecosystem mapping. Further studies are needed analyse other bodies, over wider optical properties.