6533b7ddfe1ef96bd12736b4
RESEARCH PRODUCT
A combined optical-microwave method to retrieve soil moisture over vegetated areas
Arnaud MialonJean-christophe CalvetCristian MattarClément AlbergelJuan C. Jiménez-muñozDominique GuyonP. RichaumeJosé A. SobrinoYann KerrJean-pierre WigneronNathalie Novellosubject
Vegetation optical depthL band010504 meteorology & atmospheric sciencesNDVItélédétection0211 other engineering and technologiesSoil science02 engineering and technologyMicrowave methodsurface temperature01 natural sciencesNormalized Difference Vegetation Index[SDV.EE.ECO]Life Sciences [q-bio]/Ecology environment/EcosystemsNDVI;LAI;LEAF AREA INDEX;SURFACE TEMPERATURE;SOIL MOISTURE;L-BAND medicineTraitement du signal et de l'imagenormalized vegetation difference index (NDVI)Electrical and Electronic EngineeringWater contentComputingMilieux_MISCELLANEOUS021101 geological & geomatics engineering0105 earth and related environmental sciencesRemote sensingSignal and Image processingsurface temperature.soil moisture (SM)Enhanced vegetation index15. Life on landLAIL-bandSOIL MOISTUREGeneral Earth and Planetary SciencesEnvironmental sciencemicrowave radiometrymedicine.symptomLEAF AREA INDEXVegetation (pathology)[SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processingMicrowavedescription
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.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2011-09-27 |