POSTER SESSION 2
10:30–12:30, Tuesday, September 15
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1135 | POSTER 66
USING THE SIMILARITY SPECTRUM EXTENDED TO THE SWIR FOR QUALITY CONTROL OF ABOVE WATER REFLECTANCE MEASUREMENTS
From theory and seaborne measurements it has been shown that the spectral shape of water-leaving radiance reflectance in the NIR (700-900 nm) is almost invariant and is governed by the reciprocal of pure water absorption. Thus the similarity NIR reflectance spectrum (“SimSpec”), normalized at 780 nm, was calculated from seaborne reflectance measurements and the epsilon parameter, that quantifies the difference between a measured water-leaving radiance reflectance spectrum and the NIR SimSpec, has been proposed and successfully used for measurement quality control (QC), e.g. in clear and moderately turbid water WATERHYPERNET sites. The SimSpec theory, however, is only valid for low and moderate reflectances since it is based on the Gordon-Morel first order reflectance model. Therefore, in highly reflective waters this correction is no longer applicable. To overcome this limitation, it is proposed here to use the alternative wavelengths at 870 nm and 1020 nm to calculate epsilon, and allow SimSpec QC and correction of water reflectance in a wider range of conditions, including the most turbid waters. This SimSpec extended to the SWIR is presented and used here for the quality control of seaborne reflectance measurements and for the improvement of sky glint correction of different sensors with suitable NIR/SWIR bands, like HYPSTAR, AERONET-OC and ASD radiometers. Its applicability is demonstrated using in situ measurements collected in the highly turbid waters of Río de la Plata (Argentina) and Gironde (France) as well as in the moderate turbid waters in the Adriatic Sea (Acqua Alta Oceanographic Tower, Italy) showing good results.
Ana Dogliotti, Inst. de Astronomía y Física del Espacio (IAFE) (CONICET/UBA), [email protected], https://orcid.org/0000-0001-8834-4374
Kevin Ruddick, Royal Belgian Institute of Natural Sciences (RBINS), [email protected], https://orcid.org/0009-0005-6098-0092
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
