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Benefits of the future sea surface salinity measurements from SMOS: Generation and characteristics of SMOS geophysical products ArchiMer
Obligis, E; Boone, C; Larnicol, G; Philipps, S; Tranchant, B; Le Traon, Pierre-yves.
Soil Moisture and Ocean Salinity (SMOS) level 2 and level 3 products are simulated and characterized over a one-year time period. A simulator is first used to evaluate the sea surface salinity (SSS) error of level 2 SMOS products. An optimal interpolation method is then adapted to map the surface salinity in order to simulate a level 3 SMOS product. The quality of the simulated products is satisfactory. The mean error of the SSS at pixel scale is around 1 psu, and the error on the final gridded product fits the Global Ocean Data Assimilation Experiment requirements (0.2 psu).
Tipo: Text Palavras-chave: Soil Moisture and Ocean Salinity SMOS; Sea surface salinity SSS; Remote sensing; Optimal interpolation; Microwave radiometry; Brightness temperatures.
Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/publication-3773.pdf
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Earth-Viewing L-Band Radiometer Sensing of Sea Surface Scattered Celestial Sky Radiation—Part II: Application to SMOS ArchiMer
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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Impact on sea surface salinity retrieval of different auxiliary data within the SMOS mission ArchiMer
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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Modeling sun glitter at L-band for sea surface salinity remote sensing with SMOS ArchiMer
Reul, Nicolas; Tenerelli, Joseph; Chapron, Bertrand; Waldteufel, P.
Since the sun is an extremely strong radiation source at L-band, accounting for sun glint over the ocean, i.e., solar radiation reflected by the sea surface toward downward-looking radiometers, raises a significant challenge for the remote sensing of sea surface salinity. This paper describes a dedicated physical model for sun glint at L-band frequencies and provides quantitative and qualitative estimates of the sun glint contamination impinging the antenna of the Microwave Imaging Radiometer with Aperture Synthesis interferometer onboard the future European Space Agency's Soil Moisture and Ocean Salinity (SMOS) mission, The sun brightness temperature expected during the mission period is first estimated from past solar flux data with an expected range of...
Tipo: Text Palavras-chave: Sun glitter; Sea surface salinity SSS; Rough surface scattering; Ocean remote sensing; Microwave radiometry.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-3565.pdf
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Overview of the First SMOS Sea Surface Salinity Products. Part I: Quality Assessment for the Second Half of 2010 ArchiMer
Reul, Nicolas; Tenerelli, Joseph; Boutin, Jaqueline; Chapron, Bertrand; Paul, Frederic; Brion, Emilie; Gaillard, Fabienne; Archer, Olivier.
Multi-angular images of the brightness temperature (TB) of the Earth at 1.4 GHz are reconstructed from the Soil Moisture and Ocean Salinity (SMOS) satellite sensor data since end 2009. Sea surface salinity (SSS) products remote sensing from space is being attempted using these data over the world oceans. The quality of the first version of the European Space Agency operational Level 2 (L2) SSS swath products is assessed in this paper, using satellite/in situ SSS data match-ups that were collected over the second half of 2010. This database reveals that 95% of the SMOS L2 products show a global error standard deviation on the order of ∼1.3 practical salinity scale. Simple spatiotemporal aggregation of the L2 products to generate monthly SSS maps at 1◦ × 1◦...
Tipo: Text Palavras-chave: L-band; Microwave radiometry; Ocean salinity; Sea surface.
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00072/18313/16109.pdf
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Overview of the SMOS sea surface salinity prototype processor ArchiMer
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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Remote Sensing of Sea Surface Salinity From CAROLS L-Band Radiometer in the Gulf of Biscay ArchiMer
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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SMOS: The Challenging Sea Surface Salinity Measurement From Space ArchiMer
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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SSM/I integrated water vapor content measurements in coastal regions: A comparison with shipborne and airborne remote sensing measurements, radiosonde measurements, and NWP model retrievals - art. no. 8056 ArchiMer
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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The emissivity of foam-covered water surface at L-band: Theoretical modeling and experimental results from the frog 2003 field experiment ArchiMer
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
Registros recuperados: 10
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