Two field experiments named WISE (WInd and Salinity Experiment) were sponsored by the European Space Agency (ESA) to better understand the wind and sea state effects on the L-band brightness temperatures. They took place at the Casablanca oil rig located in the North Mediterranean Sea, 40 km off shore the Ebro river delta: WISE 2000 from November 25 to December 18, 2000, and continued during the January 9 to 16, 2001, and WISE 2001 from October 23 to November 22, 2001. During the spring of 2003, under Spanish National funds, a third field experiment named FROG (Foam, Rain, Oil slicks and GPS reflectometry) took place at the Ebro river delta, to measure the phenomena that were not completely understood during the WISE field experiments, mainly the effect of foam and rain. In order to achieve the objectives of the WISE field experiments the LAURA L-band fully polarimetric radiometer from the Technical University of Catalonia (UPC) was mounted on the Casablanca oil-rig at the 32 meters deck above the sea surface, pointing to the North and North-West, in the direction of the dominant winds. In this paper we present the results of the first study to determine the relationship between the brightness temperature and the sea state.
Sea surface salinity (SSS) measurement is one of the objectives of ESA’s SMOS (Soil Moisture and Ocean Salinity) Earth Explorer Opportunity mission. SMOS’s objective is to provide global soil moisture and sea salinity maps using the MIRAS L-band aperture synthesis interferometric radiometer. Since the sea salinity signature exhibits a very small brightness temperature dynamic margin, it can only be accurately retrieved if the sea surface emissivity at L-band is properly modeled. In addition to the sea salinity signature, other factors influencing the emissivity are the sea surface temperature, and the sea surface roughness induced by wind, the large scale roughness created by swell, and the foam
emissivity. This article is focused on the estimation of the sea surface spectrum, which describes sea roughness, training a neural network with wind and roughness data obtained during WISE 2000/2001 (WInd and Salinity Experiment).