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| Registros recuperados: 10 | |
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| Zine, S; Boutin, J; Font, J; Reul, Nicolas; Waldteufel, P; Gabarro, C; Tenerelli, Joseph; Petitcolin, F; Vergely, J; Talone, M; Delwart, S. |
| The L-band interferometric radiometer onboard the Soil Moisture and Ocean Salinity mission will measure polarized brightness temperatures (Tb). The measurements are affected by strong radiometric noise. However, during a satellite overpass, numerous measurements are acquired at various incidence angles at the same location on the Earth's surface. The sea surface salinity (SSS) retrieval algorithm implemented in the Level 2 Salinity Prototype Processor (L2SPP) is based on an iterative inversion method that minimizes the differences between Tb measured at different incidence angles and Tb simulated by a full forward model. The iterative method is initialized with a first-guess surface salinity that is iteratively modified until an optimal fit between the... |
| Tipo: Text |
Palavras-chave: Salinity; Oceanography; Microwave radiometry. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3914.pdf |
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| Martin, Adrien; Boutin, Jacqueline; Hauser, Daniele; Reverdin, Gilles; Parde, Mickael; Zribi, Mehrez; Fanise, Pascal; Chanut, Jerome; Lazure, Pascal; Tenerelli, Joseph; Reul, Nicolas. |
| A renewal of interest for the radiometric L-band Sea Surface Salinity (SSS) remote sensing appeared in the 1990s and led to the Soil Moisture and Ocean Salinity (SMOS) satellite launched in November 2009 and to the Aquarius mission (launched in June 2011). However, due to low signal to noise ratio, retrieving SSS from L-band radiometry is very challenging. In order to validate and improve L-band radiative transfer model and salinity retrieval method used in SMOS data processing, the Cooperative Airborne Radiometer for Ocean and Land Studies (CAROLS) was developed. We analyze here a coastal flight (20 May 2009), in the Gulf of Biscay, characterized by strong SSS gradients (28 to 35 pss-78). Extensive in-situ measurements were gathered along the plane track.... |
| Tipo: Text |
Palavras-chave: L-band; Microwave radiometry; Remote sensing; Retrieval method; Sea surface salinity (SSS); Soil Moisture and Ocean Salinity (SMOS); Wind speed. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00079/18997/16600.pdf |
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| Font, Jordi; Camps, Adriano; Borges, Andres; Martin-neira, Manuel; Boutin, Jacqueline; Reul, Nicolas; Kerr, Yann H.; Hahne, Achim; Mecklenburg, Susanne. |
| Soil Moisture and Ocean Salinity, European Space Agency, is the first satellite mission addressing the challenge of measuring sea surface salinity from space. It uses an L-band microwave interferometric radiometer with aperture synthesis (MIRAS) that generates brightness temperature images, from which both geophysical variables are computed. The retrieval of salinity requires very demanding performances of the instrument in terms of calibration and stability. This paper highlights the importance of ocean salinity for the Earth's water cycle and climate; provides a detailed description of the MIRAS instrument, its principles of operation, calibration, and image-reconstruction techniques; and presents the algorithmic approach implemented for the retrieval of... |
| Tipo: Text |
Palavras-chave: Aperture synthesis; Imaging; Microwave radiometry; Remote sensing; Salinity. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00004/11482/8066.pdf |
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| Camps, A; Vall-ilossera, M; Villarino, R; Reul, Nicolas; Chapron, Bertrand; Corbella, I; Duffo, N; Torres, F; Miranda, Jj; Sabia, R; Monerris, A; Rodriguez, R. |
| 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... |
| Tipo: Text |
Palavras-chave: Brightness temperature; Emission; Foam; Microwave radiometry; Salinity; Sea. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/00000/10940/9268.pdf |
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| Sabia, Roberto; Camps, A; Vall Ilossera, M; Reul, Nicolas. |
| Aiming to provide sea surface salinity (SSS) maps with a spatiotemporal averaged accuracy of 0.1 psu (practical salinity units), the Soil Moisture and Ocean Salinity (SMOS) community is increasingly focusing on the determination of a robust inversion scheme to enable SSS retrieval from L-band brightness temperature data. In the framework of the Synergetic Aspects and Auxiliary Data Concepts for Sea Surface Salinity Measurements from Space project, efforts have been oriented toward a quantitative analysis of SSS retrieval using different auxiliary data sets. This paper aims to contribute to the assessment of the SMOS salinity retrieval error budget in view of the upcoming SMOS mission ground segment development. Aiming to do that, different models and... |
| Tipo: Text |
Palavras-chave: Spatiotemporal averaging; Sea salinity; Microwave radiometry; Auxiliary data. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2011.pdf |
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| Reul, Nicolas; Tenerelli, Joseph; Floury, N; Chapron, Bertrand. |
| We examine how the rough sea surface scattering of L-band celestial sky radiation might affect the measurements of the future European Space Agency Soil Moisture and Ocean Salinity (SMOS) mission. For this purpose, we combined data from several surveys to build a comprehensive all-sky L-band celestial sky brightness temperature map for the SMOS mission that includes the continuum radiation and the hydrogen line emission rescaled for the SMOS bandwidth. We also constructed a separate map of strong and very localized sources that may exhibit L-band brightness temperatures exceeding 1000 K. Scattering by the roughened ocean surface of radiation from even the strongest localized sources is found to reduce the contributions from these localized strong sources... |
| Tipo: Text |
Palavras-chave: Sea surface electromagnetic scattering; Microwave radiometry. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3636.pdf |
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| Flamant, C; Pelon, J; Eymard, L; Tournadre, Jean. |
| [1] The Special Sensor Microwave Imager (SSM/I) integrated water vapor content (IWVC) estimates in a coastal region during nonstationary cold-air outbreak conditions are analyzed using IWVC retrievals obtained from shipborne microwave radiometry (DRAKKAR), water vapor differential absorption laser remote sensing (LEANDRE 2), radiosonde measurements, and numerical weather prediction (NWP) model ALADIN of Meteo-France. The study focuses on the 24 March 1998 Tramontane/Mistral event, which occurred over the Gulf of Lion (GoL) (western Mediterranean) in the framework of the flux, etat de mer et teledetection en condition de fetch variable (FETCH) experiment. Comparisons of SSM/I and ALADIN IWVCs with collocated shipborne microwave radiometry, at distances from... |
| Tipo: Text |
Palavras-chave: SSM/I; Lidar; Microwave radiometry; Integrated water vapor content; Mistral; FETCH. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00000/10184/7733.pdf |
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| Registros recuperados: 10 | |
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