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)

ANA DOGLIOTTI; PABLO PERNA; ESTEFANÍA PIEGARI; LUCAS RUBINSTEIN

Frascati

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

ESA

Validation of satellite-derived products, in particular water reflectance, using in situ data is essential to ensure the quality of derived parameters, like turbidity and chlorophyll-a concentration (Chl-a), useful for water quality monitoring. The use of autonomous systems, like AERONET-OC, has shown to be effective for increasing the number of validation match-ups compared to oceanographic cruises. However, the multispectral nature of the instrument used in the AERONET-OC network, prevents its use to validate missions with different spectral band configurations.In the frame of H2020/HYPERNETS project, a new hyperspectral radiometer (HYPSTAR®) with a pointing system and auxiliary sensors have been designed to provide fine spectral resolution (2nm FWHM) in the VIS/NIR region with high quality measurements at lower cost. Within this project an autonomous hyperspectral system has been deployed for the first time in the turbid waters of 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 the performance of the standard L2 Collection-3 as well as other different atmospheric correction, like DSF (Dark Spectral Fitting), CC2RR (Case 2 Regional CoastColour), and POLYMER (POLYnomial based algorithm applied to MERIS) processors applied to Sentinel-3 A/B data using the first six months of automatic in situ measurements collected in coincidence with the S3 satellite overpasses during this period.