Author:
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Rodríguez, R; Monerris Belda, Alessandra; Sabia, Roberto; Miranda Mendoza, Jorge José; Camps Carmona, Adriano José; Vall-Llossera Ferran, Mercedes Magdalena; Villarino Villarino, Ramón; Reul, N; Chapron, B; Corbella Sanahuja, Ignasi; Duffo Ubeda, Núria; Torres Torres, Francisco
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Abstract:
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Sea surface salinity can be measured by microwave
radiometry at L-band (1400–1427 MHz). This frequency is a
compromise between sensitivity to the salinity, small atmospheric
perturbation, and reasonable pixel resolution. The description
of the ocean emission depends on two main factors: 1) the sea
water permittivity, which is a function of salinity, temperature,
and frequency, and 2) the sea surface state, which depends on the
wind-induced wave spectrum, swell, and rain-induced roughness
spectrum, and by the foam coverage and its emissivity. This study
presents a simplified two-layer emission model for foam-covered
water and the results of a controlled experiment to measure the
foam emissivity as a function of salinity, foam thickness, incidence
angle, and polarization. Experimental results are presented, and
then compared to the two-layer foam emission model with the
measured foam parameters used as input model parameters. At
37 psu salt water the foam-induced emissivity increase is 0.007
per millimeter of foam thickness (extrapolated to nadir), increasing
with increasing incidence angles at vertical polarization,
and decreasing with |