| type de publication : |
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Articles dans des revues avec comité de lecture |
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| domaine : |
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Sciences du Vivant/Ecologie, Environnement/Ecosystèmes
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| titre : |
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A combined optical-microwave method to retrieve soil moisture over vegetated areas |
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| auteur(s) : |
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C. Mattar ( ) 1, J.-P. Wigneron ( ) 2, J.A. Sobrino ( ) 1, N. Novello 2, J.-C. Calvet ( ) 3, C. Albergel 4, P. Richaume 5, A. Mialon 5, D. Guyon 2, J.C. Jimenez-Munoz 1, Y.H. Kerr ( ) 5 |
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| laboratoire : |
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| résumé : |
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A simple approach for correcting for the effect of vegetation in the estimation of the surface soil moisture (wS) from L-band passive microwave observations is presented in this study. The approach is based on semi-empirical relationships between soil moisture and the polarized reflectivity including the effect of the vegetation optical depth which is parameterized as a function of the normalized vegetation difference index (NDVI). The method was tested against in situ measurements collected over a grass site from 2004 to 2007 (SMOSREX experiment). Two polarizations (horizontal/vertical) and five incidence angles (20◦, 30◦, 40◦, 50◦, and 60◦) were considered in the analysis. The best wS estimations were obtained when using both polarizations at an angle of 40◦. The average accuracy in the soil moisture retrievals was found to be approximately 0.06 m3/m3, improving the estimations by 0.02 m3/m3 with respect to the case in which the vegetation effect is not considered. The results indicate that information on vegetation (through a vegetation index such as NDVI) is useful for the estimation of soil moisture through the semi-empirical regressions. |
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langue du texte intégral : |
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Anglais |
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| journal : |
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| IEEE Transactions on Geoscience and Remote Sensing |
| Publisher |
Institute of Electrical and Electronics Engineers (IEEE) |
| ISSN |
0196-2892 |
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| Audience : |
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non spécifiée |
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| date de publication : |
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2012 |
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| volume : |
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50 |
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| numéro : |
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5 |
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| page, identifiant, ... : |
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1404-1413 |
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| mots-clés : |
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L-band – microwave radiometry – normalized vegetation difference index (NDVI) – soil moisture (SM) – surface temperature. |
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