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Effect of corn on C-an L-band radar backscatter: a correction method for soil moisture retrieval / A. Joseph in Remote sensing of environment, vol 114 n° 11 (15/11/2010)  

Public [article]  inRemote sensing of environment > vol 114 n° 11 (15/11/2010) . - pp 2417 - 2430 Titre : Effect of corn on C-an L-band radar backscatter: a correction method for soil moisture retrieval Type de document : Article/Communication Auteurs : A. Joseph, Auteur ; R. Van Der Velde, Auteur ; P. O'neill, Auteur ; R. Lang, Auteur ; T. Gish, Auteur Année de publication : 2010 Article en page(s) : pp 2417 - 2430 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] angle d'incidence [Termes IGN] bande C [Termes IGN] bande L [Termes IGN] biomasse [Termes IGN] humidité du sol [Termes IGN] maïs (céréale) [Termes IGN] polarimétrie radar [Termes IGN] rétrodiffusion [Termes IGN] teneur en eau de la végétation Résumé : (Auteur) This paper discusses the effects of vegetation on C- (4.75 GHz) and L- (1.6 GHz) band backscattering (Ó) measured throughout a growth cycle at incidence angles of 15, 35 and 55°. The utilized Ó data set was collected by a truck mounted scatterometer over a corn field and is supported by a comprehensive set of ground measurements, including soil moisture and vegetation biomass. Comparison of Ó measurement against simulations by the Integral Equation Method (IEM) surface scattering model (Fung et al., 1992) shows that the Ó measurements are dominated either by an attenuated soil return or by scattering from vegetation depending on the antenna configuration and growth stage. Further, the measured Ó is found to be sensitive to soil moisture even at peak biomass and large incidence angles, which is attributed to scattering along the soil-vegetation pathway. For the simulation of C-band Ó and the retrieval of soil moisture two methods have been applied, which are the semi-empirical water cloud model (Attema & Ulaby, 1978) and a novel method. This alternative method uses the empirical relationships between the vegetation water content (W) and the ratio of the bare soil and the measured Ó to correct for vegetation. It is found that this alternative method is superior in reproducing the measured Ó as well as retrieving soil moisture. The highest retrieval accuracies are obtained at a 35° incidence angle leading to RMSD's of 0.044 and 0.037 m3 m- 3 for the HH and VV-polarization, respectively. In addition, the sensitivity of these soil moisture retrievals to W and surface roughness parameter uncertainties is investigated. Numéro de notice : A2010-400 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2010.05.017 En ligne : https://doi.org/10.1016/j.rse.2010.05.017 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30593 [article]