Oral Session 9 | Thursday, October 6, 09:20–09:40 | Abstract 536
Uncertainties in remote sensing reflectance from OC satellites and their mitigation
Remote sensing reflectance (Rrs) spectra from SNPP VIIRS and Sentinel 3A and 3B OLCI are compared with Rrs from MOBY and several AERONET-OC stations in US and Europe and the differences are incorporated into a model to decompose Rrs uncertainties spectra into their components, taking advantage of different spectral shapes of radiances related to molecular and aerosol scattering, surface effects and glint. It is shown that uncertainties in remote sensing reflectance products have primarily Rayleigh-type spectral components, are associated with the variability of Rayleigh optical thickness and surface effects, and mostly explain the frequency of negative Rrs in coastal waters. The contributions of inaccuracies in aerosol models, which are usually considered as a major factor in uncertainties, were found to be small. The spectral term of water variability inside the pixel(s), which was considered proportional to Rrs, had also a pronounced peak in the green part of the spectrum in coastal waters. Uncertainties in Rrs were typically about 10–3 sr–1 at 412 nm for VIIRS, and about twice higher for OLCI. The impact of surface effects was estimated separately by accurate measurements of wave slopes variances in several ocean cruises using our multispectral polarimetric system together with a modified polarimetric slope-sensing technique. Several approaches are analyzed for the mitigation of Rrs uncertainties in the blue bands, showing possibilities of their significant reduction in coastal waters.
Alex Gilerson, City College of New York
Eder Herrera-Estrella, City College of New York
Jacopo Agagliate, City College of New York
Mateusz Malinowski, City College of New York