The emissivity of foam-covered water surface at L-band: theoretical modeling and experimental results from the FROG 2003 field experiment
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 w...
| Autores: | , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2005 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/10108 |
| Acceso en línea: | https://hdl.handle.net/2117/10108 https://dx.doi.org/10.1109/TGRS.2004.839651 |
| Access Level: | acceso abierto |
| Palabra clave: | Brightness temperature Microwave remote sensing Signal theory (Telecommunication) Microones -- Mesurament Senyal, Teoria del (Telecomunicació) Oceanografia Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Radiocomunicació i exploració electromagnètica |
| Sumario: | 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 |
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