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A combined optical-microwave method to retrieve soil moisture over vegetated areas
Abstract : 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.
Cited literature [36 references]
https://hal.ird.fr/ird-00700888
Contributor : Dominique Bruel <>
Submitted on : Thursday, May 24, 2012 - 11:21:11 AM
Last modification on : Thursday, March 26, 2020 - 12:04:08 PM
Document(s) archivé(s) le : Saturday, August 25, 2012 - 2:26:15 AM
Contributor : Dominique Bruel <>
Submitted on : Thursday, May 24, 2012 - 11:21:11 AM
Last modification on : Thursday, March 26, 2020 - 12:04:08 PM
Document(s) archivé(s) le : Saturday, August 25, 2012 - 2:26:15 AM
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