Validation of Sentinel-3/OLCI water reflectance using automatic hyperspectral in-situ observations in the turbid waters of Río de la Plata, Argentina (HYPERNETS Site)

DOGLIOTTI, A.I.; PIEGARI, E.; RUBINSTEIN, L.; PERNA. P

Encuentro; 7th Sentinel-3 Validation Team Meeting 2022; 2022

Validation of satellite-derived products, inparticular water reflectance, using insitu data is essential to ensure the quality of derived parameters, liketurbidity and chlorophyll-a concentration (Chl-a), useful for water quality monitoring. The use of autonomoussystems, like AERONET-OC, has shown to be effective for increasing the numberof validation match-ups compared to oceanographic cruises. However, the multispectralnature of the instrument used in the AERONET-OC network, prevents its use tovalidate missions with different spectral band configurations. In the frame ofH2020/HYPERNETS project, a new hyperspectral radiometer (HYPSTAR®) with a pointing system and auxiliary sensors havebeen designed to provide fine spectral resolution (2nm FWHM) in the VIS/NIRregion with high quality measurements at lower cost. Within this project an autonomoushyperspectral system has been deployed for the first time in the turbid watersof Río de la Plata estuary close to the city of Buenos Aires in South America, an ideal scenario to test atmospheric correction algorithms performance.In the present study, we assessed theperformance of the standard L2 Collection-3 as well as other differentatmospheric correction, like DSF (Dark Spectral Fitting), CC2RR (Case 2 Regional CoastColour), and POLYMER (POLYnomial based algorithm applied toMERIS) processors applied to Sentinel-3 A/B datausing the first six months of automatic insitu measurements collected in coincidence with the S3 satellite overpassesduring this period.