Centre de documentation
scientifique

Dépouillements

Evaluating an improved parameterization of the soil emission in L-MEB / Jean-Pierre Wigneron in IEEE Transactions on geoscience and remote sensing, vol 49 n° 4 (April 2011)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 49 n° 4 (April 2011) . - pp 1177 - 1189 Titre : Evaluating an improved parameterization of the soil emission in L-MEB Type de document : Article/Communication Auteurs : Jean-Pierre Wigneron, Auteur ; A. Chanzy, Auteur ; Yann H. Kerr, Auteur ; et al., Auteur Année de publication : 2011 Article en page(s) : pp 1177 - 1189 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image [Termes IGN] bande L [Termes IGN] biosphère [Termes IGN] emissivité [Termes IGN] étalonnage de modèle [Termes IGN] humidité du sol [Termes IGN] rugosité du sol [Termes IGN] télédétection en hyperfréquence Résumé : (Auteur) In the forward model [L-band microwave emission of the biosphere (L-MEB)] used in the Soil Moisture and Ocean Salinity level-2 retrieval algorithm, modeling of the roughness effects is based on a simple semiempirical approach using three main “roughness” model parameters: HR, QR, and NR. In many studies, the two parameters QR and NR are set to zero. However, recent results in the literature showed that this is too approximate to accurately simulate the microwave emission of the rough soil surfaces at L-band. To investigate this, a reanalysis of the PORTOS-93 data set was carried out in this paper, considering a large range of roughness conditions. First, the results confirmed that QR could be set to zero. Second, a refinement of the L-MEB soil model, considering values of NR for both polarizations (namely, NRV and NRH), improved the model accuracy. Furthermore, simple calibrations relating the retrieved values of the roughness model parameters HR and (NRH - NRV) to the standard deviation of the surface height were developed. This new calibration of L-MEB provided a good accuracy (better than 5 K) over a large range of soil roughness and moisture conditions of the PORTOS-93 data set. Conversely, the calibrations of the roughness effects based on the Choudhury approach, which is still widely used, provided unrealistic values of surface emissivities for medium or large roughness conditions. Numéro de notice : A2011-130 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2010.2075935 Date de publication en ligne : 09/11/2010 En ligne : https://doi.org/10.1109/TGRS.2010.2075935 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30909 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
065-2011041	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Electromagnetic land surface classification through integration of optical and radar remote sensing data / J. Baek in IEEE Transactions on geoscience and remote sensing, vol 49 n° 4 (April 2011)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 49 n° 4 (April 2011) . - pp 1214 - 1222 Titre : Electromagnetic land surface classification through integration of optical and radar remote sensing data Type de document : Article/Communication Auteurs : J. Baek, Auteur ; W. Kim, Auteur ; et al., Auteur Année de publication : 2011 Article en page(s) : pp 1214 - 1222 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image mixte [Termes IGN] Alberta (Canada) [Termes IGN] analyse en composantes principales [Termes IGN] classification dirigée [Termes IGN] fusion de données multisource [Termes IGN] image ALOS-PALSAR [Termes IGN] image Landsat-TM [Termes IGN] image optique [Termes IGN] image Quickbird [Termes IGN] image radar [Termes IGN] MNS SRTM Résumé : (Auteur) We present a nonhierarchical electromagnetic (EM) land surface classification method through the integration of satellite multispectral high-resolution optical and polarized radar images of central Alberta near the Saskatchewan border. We implement a conventional supervised land surface classification method and a principal component analysis to a QuickBird image. The EM properties are then assigned to the classified surfaces to produce hierarchical EM land classification maps. To further classify a hierarchical EM surface (i.e., dielectric constant), we calculate the root-mean-square surface height with a Shuttle Radar Topography Mission 3-arc-second digital elevation model and the temperatures from a thermal band of a Landsat-5 Thematic Mapper image. We also calculate the backscattering coefficients from the Advanced Land Observing Satellite Phased Array L-band Synthetic Aperture Radar image. Using these estimated values, we calculate the intrinsic weighting factors with the Dubois (1995) model for less vegetated land areas and the Ulaby (1986) model for open water areas. By applying these weighting factors to the hierarchical EM surface, we generate a nonhierarchical higher resolution EM surface map of the study area. Numéro de notice : A2011-131 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2010.2096513 Date de publication en ligne : 06/01/2011 En ligne : https://doi.org/10.1109/TGRS.2010.2096513 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30910 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
065-2011041	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Potential use of surface-sensitive microwave observations over land in numerical weather prediction / E. Gerard in IEEE Transactions on geoscience and remote sensing, vol 49 n° 4 (April 2011)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 49 n° 4 (April 2011) . - pp 1251 - 1262 Titre : Potential use of surface-sensitive microwave observations over land in numerical weather prediction Type de document : Article/Communication Auteurs : E. Gerard, Auteur ; Fatima Karbou, Auteur ; Florence Rabier, Auteur Année de publication : 2011 Article en page(s) : pp 1251 - 1262 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] assimilation des données [Termes IGN] intégration de données [Termes IGN] prévision météorologique [Termes IGN] Special sensor microwave imager [Termes IGN] télédétection en hyperfréquence Résumé : (Auteur) This paper describes several sensitivity studies carried out with the French global 4-D-Var system to check its ability to assimilate surface-sensitive observations over land from the Special Sensor Microwave Imager (SSM/I). As well as a sound knowledge of land-surface parameters, the assimilation of SSM/I observations requires effective rain-detection and bias-correction algorithms. Three sensitivity components are hence analyzed with a special emphasis on the land-surface emissivity at SSM/I frequencies estimated from satellite observations. Several rain algorithms were tested to reject cloudy/rainy observations over land, and the bias-correction scheme was adapted to improve its performance over land and sea surfaces. Once these problems have been outlined, a global 4-D-Var assimilation experiment which assimilates SSM/I observations over land surfaces was run and compared with a control experiment. The impact on forecast scores has been found to be globally positive. Nevertheless, the very high sensitivity of SSM/I to each of the three components presented in this study is characterized by opposite effects that, once clustered together, lead to some residual biases over land due to their combined effects. Numéro de notice : A2011-132 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2010.2075936 Date de publication en ligne : 21/10/2010 En ligne : https://doi.org/10.1109/TGRS.2010.2075936 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30911 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
065-2011041	RAB	Revue	Centre de documentation	En réserve L003	Disponible