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Canopy directional emissivity: comparison between models / J.A. Sobrino in Remote sensing of environment, vol 99 n° 3 (30/11/2005)
[article]
Titre : Canopy directional emissivity: comparison between models Type de document : Article/Communication Auteurs : J.A. Sobrino, Auteur ; J.C. Jimenez-Munoz, Auteur ; W. Verhoef, Auteur Année de publication : 2005 Article en page(s) : pp 304 - 314 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] analyse comparative
[Termes IGN] couvert végétal
[Termes IGN] emissivité
[Termes IGN] évapotranspiration
[Termes IGN] modèle de transfert radiatif
[Termes IGN] radiance
[Termes IGN] rayonnement infrarouge thermique
[Termes IGN] température au solRésumé : (Auteur) Land surface temperature plays an important role in many environmental studies, as for example the estimation of heat fluxes and evapotranspiration. In order to obtain accurate values of land surface temperature, atmospheric, emissivity and angular effects should be corrected. This paper focuses on the analysis of the angular variation of canopy emissivity, which is an important variable that has to be known to correct surface radiances and obtain surface temperatures. Emissivity is also involved in the atmospheric corrections since it appears in the reflected, downwelling atmospheric term. For this purpose, five different methods for simulating directional canopy emissivity have been analyzed and compared. The five methods are composed of two geometrical models, developed by Sobrino et al. and Snyder and Wan, in which the vegetation is considered as an opaque medium, and three are based on radiative transfer models, developed by François et al., Snyder and Wan and Verhoef et al., in which the vegetation is considered as a turbid medium. Over surfaces with sparse and low vegetation cover, high angular variations of canopy emissivity are obtained, with differences between at-nadir view and 80° of 0.03. Over fully vegetated surfaces angular effects on emissivity are negligible when radiative transfer models are applied, so in these situations the angular variations on emissivity are not critical on the retrieved land surface temperature from remote sensing data. Angular variations on emissivity are lower when the emissivity of the soil and the emissivity of the vegetation are closer. All the models considered assume Lambertian behaviour for the soil and the leaves. This assumption is also discussed, showing a different behaviour of directional canopy emissivity when a non-Lambertian soil is considered. Numéro de notice : A2005-459 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2005.09.005 En ligne : https://doi.org/10.1016/j.rse.2005.09.005 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27595
in Remote sensing of environment > vol 99 n° 3 (30/11/2005) . - pp 304 - 314[article]Emissivity maps to retrieve land-surface temperature from MSG/SEVIRI / L.F. Peres in IEEE Transactions on geoscience and remote sensing, vol 43 n° 8 (August 2005)
[article]
Titre : Emissivity maps to retrieve land-surface temperature from MSG/SEVIRI Type de document : Article/Communication Auteurs : L.F. Peres, Auteur ; C.C. Dacamara, Auteur Année de publication : 2005 Article en page(s) : pp 1834 - 1844 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse comparative
[Termes IGN] bande infrarouge
[Termes IGN] couvert végétal
[Termes IGN] emissivité
[Termes IGN] image MSG-SEVIRI
[Termes IGN] image Terra-MODIS
[Termes IGN] température au solRésumé : (Auteur) Retrieval of land-surface temperature (LST) using data from the METEOSAT Second Generation-1 (MSG) Spinning Enhanced Visible and Infrared Imager (SEVIRI) requires adequate estimates of land-surface emissivity (LSE). In this context, LSE maps for SEVIRI channels IR3.9, IR8.7, IR10.8, and IR12.0 were developed based on the vegetation cover method. A broadband LSE map (3-14 um) was also developed for estimating longwave surface fluxes that may prove to be useful in both energy balance and climate modeling studies. LSE is estimated from conventional static land-cover classifications, LSE spectral data for each land cover, and fractional vegetation cover (FVC) information. Both International Geosphere-Biosphere Program (IGBP) Data and Information System (DIS) and Moderate Resolution Imaging Spectrometer (MODIS) MOD12Q1 land-cover products were used to build the LSE maps. Data on LSE were obtained from the Johns Hopkins University and Jet Propulsion Laboratory spectral libraries included in the Advanced Spaceborne Thermal Emission and Reflection Radiometer spectral library, as well as from the MODIS University of California-Santa Barbara spectral library. FVC data for each pixel were derived based on the normalized differential vegetation index. Depending on land cover, the LSE errors for channels IR3.9 and IR8.7 spatially vary from +0.6% to +24% and +0.1% to +33%, respectively, whereas the broadband spectrum errors lie between +0.3% and +7%. In the case of channels IR10.8 and IR12.0,73% of the land surfaces within the MSG disk present relative errors less than +1.5%, and almost all (26%) of the remaining areas have relative errors of +2.0 %. Developed LSE maps provide a first estimate of the ranges of LSE in SEVIRI channels for each surface type, and obtained results may be used to assess the sensitivity of algorithms where an a priori knowledge of LSE is required. Numéro de notice : A2005-392 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2005.851172 En ligne : https://doi.org/10.1109/TGRS.2005.851172 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27528
in IEEE Transactions on geoscience and remote sensing > vol 43 n° 8 (August 2005) . - pp 1834 - 1844[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-05081 RAB Revue Centre de documentation En réserve L003 Disponible Separating surface emissivity and temperature using two-channel spectral indices and emissivity composites and comparison with a vegetation fraction method / P. Dash in Remote sensing of environment, vol 96 n° 1 (15/05/2005)
[article]
Titre : Separating surface emissivity and temperature using two-channel spectral indices and emissivity composites and comparison with a vegetation fraction method Type de document : Article/Communication Auteurs : P. Dash, Auteur ; F. Göttsche, Auteur ; et al., Auteur Année de publication : 2005 Article en page(s) : pp 1 - 17 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] analyse comparative
[Termes IGN] correction atmosphérique
[Termes IGN] données de terrain
[Termes IGN] données météorologiques
[Termes IGN] éclairement énergétique
[Termes IGN] emissivité
[Termes IGN] erreur
[Termes IGN] image NOAA-AVHRR
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] radiance
[Termes IGN] rayonnement infrarouge thermique
[Termes IGN] saison
[Termes IGN] simulation de surface
[Termes IGN] température au sol
[Termes IGN] thermal infrared multispectral scannerRésumé : (Auteur) The temperature-independent thermal infrared spectral indices (TISI) method is employed for the separation of land surface temperature (LST) and emissivity from surface radiances (atmospherically corrected satellite data). The daytime reflected solar irradiance and the surface emission at ~3.8 um have comparable magnitudes. Using surface radiances and a combination of day-night 2-channel TISI ratios, the ~3.8 um reflectivity is derived. For implementing the TISI method, coefficients for NOAA 9-16 AVHRR channels are obtained. A numerical analysis with simulated surface radiances shows that for most surface types (showing nearly Lambertian behavior) the achievable accuracy is ~0.005 for emissivity (AVHRR channel-5) and ~1.5 K for LST. Data from the European Centre for Medium-Range Weather Forecasts (ECMWF) is used for calculation of atmospheric attenuation. Comparisons are made over a part of central Europe on two différent dates (seasons). Clouds pose a major problem to surface observations; hence, monthly emissivity composites are derived. Additionally, using TISI-based monthly composites of emissivities, a normalized difference vegetation index (NDVI)-based method is tuned to the particular study area and the results are intercompared. Once the coefficients are known, the NDVI method is easily implemented but holds well only for vegetated areas. The error of the NDVI-based emissivities (with respect to the TISI results) ranges between -0.038 and 0.032, but for vegetated areas the peak of the error-histogram is at ~0.002. The algorithm for retrieving emissivity via TISI was validated with synthetic data. Due to the different spatial scales of satellite and surface measurements and the lack of homogeneous areas, which are representative for low-resolution pixels and ground measurements, ground-validation is a daunting task. However, for operational products ground-truth validation is necessary. Therefore, also an approach to identify suitable validation sites for meteorological satellite products in Europe is described. Numéro de notice : A2005-209 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2004.12.023 En ligne : https://doi.org/10.1016/j.rse.2004.12.023 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27346
in Remote sensing of environment > vol 96 n° 1 (15/05/2005) . - pp 1 - 17[article]Microwave land emissivity calculations using AMSU measurements / Fatima Karbou in IEEE Transactions on geoscience and remote sensing, vol 43 n° 5 (May 2005)
[article]
Titre : Microwave land emissivity calculations using AMSU measurements Type de document : Article/Communication Auteurs : Fatima Karbou, Auteur ; C. Prigent, Auteur Année de publication : 2005 Article en page(s) : pp 948 - 959 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] Advanced Microwave Sounding Unit
[Termes IGN] emissivité
[Termes IGN] image DMSP-SSM/I
[Termes IGN] image NOAA-AMSU
[Termes IGN] surface du sol
[Termes IGN] télédétection en hyperfréquenceRésumé : (Auteur) Atmospheric parameter retrievals over land from Advanced Microwave Sounding Unit (AMSU) measurements, such as atmospheric temperature and moisture profiles, could be possible using a reliable estimate of the land emissivity. The land surface emissivities have been calculated using six months of data, for 30 beam positions (observation zenith angles from 58° to +58°) and the 23.8-, 31.4-, 50.3-, 89-, and 150-GHz channels. The emissivity calculation covers a large area including Africa, Eurasia, and Eastern South America. The day-to-day variability of the emissivity is less than 2% in these channels. The angular and spectral dependence of the emissivity is studied. The obtained AMSU emissivities are in good agreement with the previously derived SSMI ones. The scan asymmetry problem has been evidenced for AMSU-A channels. And possible extrapolation of the emissivity from window channels to sounding ones has been successfully tested. Numéro de notice : A2005-214 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2004.837503 En ligne : https://doi.org/10.1109/TGRS.2004.837503 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27351
in IEEE Transactions on geoscience and remote sensing > vol 43 n° 5 (May 2005) . - pp 948 - 959[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-05051 RAB Revue Centre de documentation En réserve L003 Disponible The emissivity of foam-covered water surface at L-band: theoretical modelling and experimental results from the frog 2003 field experiment / A. Camps in IEEE Transactions on geoscience and remote sensing, vol 43 n° 5 (May 2005)
[article]
Titre : The emissivity of foam-covered water surface at L-band: theoretical modelling and experimental results from the frog 2003 field experiment Type de document : Article/Communication Auteurs : A. Camps, Auteur ; M. Vall-Llossera, Auteur ; R. Villarino, Auteur Année de publication : 2005 Article en page(s) : pp 925 - 937 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] angle d'incidence
[Termes IGN] bande L
[Termes IGN] emissivité
[Termes IGN] houle
[Termes IGN] polarisation
[Termes IGN] salinité
[Termes IGN] spectre électromagnétique
[Termes IGN] surface de la mer
[Termes IGN] télédétection en hyperfréquenceRésumé : (Auteur) Sea surface salinity can he measured by microwave radiometry at L-band (1400-1427 MHz). This frequency is a compromise between sensitivity to the salinity, small atmospheric perturbation, and reasonable pixel resolution. The description of the ocean emission depends on two main factors: 1) the sea water permittivity, which is a function of salinity, temperature, and frequency, and 2) the sea surface state, which depends on the wind-induced wave spectrum, swell, and rain-induced roughness spectrum, and by the foam coverage and its emissivity. This study presents a simplified two-layer emission model for foam-covered water and the results of a controlled experiment to measure the foam emissivity as a function of salinity, foam thickness, incidence angle, and polarization. Experimental results are presented, and then compared to the two-layer foam emission model with the measured foam parameters used as input model parameters. At 37 psu salt water the foam-induced emissivity increase is ~0.007 per millimeter of foam thickness (extrapolated to nadir), increasing with increasing incidence angles at vertical polarization, and decreasing with increasing incidence angles at horizontal polarization. Numéro de notice : A2005-213 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2004.839651 En ligne : https://doi.org/10.1109/TGRS.2004.839651 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27350
in IEEE Transactions on geoscience and remote sensing > vol 43 n° 5 (May 2005) . - pp 925 - 937[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-05051 RAB Revue Centre de documentation En réserve L003 Disponible Mapping micro-urban heat islands using NOAA/AVHRR images and CORINE Land Cover : an application to coastal of Greece / M. Stathopoulou in International Journal of Remote Sensing IJRS, vol 25 n° 12 (June 2004)PermalinkComparison of land surface emissivity and radiometric temperature derived from MODIS and ASTER sensors / F. Jacob in Remote sensing of environment, vol 90 n° 2 (30/03/2004)PermalinkRetrievals of low integrated water vapor using MIR and SSM/T-2 measurements / J.R. Wang in IEEE Transactions on geoscience and remote sensing, vol 41 n° 3 (March 2003)PermalinkIncorporating surface emissivity into a thermal atmospheric correction / N.A. Brunsell in Photogrammetric Engineering & Remote Sensing, PERS, vol 68 n° 12 (December 2002)PermalinkSimulating L-band emission of forests in view of future satellite applications / P. Ferrazzoli in IEEE Transactions on geoscience and remote sensing, vol 40 n° 12 (December 2002)PermalinkA temperature and emissivity separation algorithm for advanced spaceborne thermal emission and reflection radiometer (ASTER) images / A.R. Gillespie in IEEE Transactions on geoscience and remote sensing, vol 36 n° 4 (July 1998)PermalinkInfluence de la rugosité de surface en radiométrie micro-onde des sols nus / L. Laguerre (1995)PermalinkTélédétection infrarouge thermique des échanges énergétiques et hydriques de la végétation en combinaison avec d'autres capteurs, actes, La-Londe-les-Maures, 20-23 septembre 1993 / T. Carlson (1994)PermalinkTemperature-independent spectral indices in thermal infrared bands / François Becker in Remote sensing of environment, vol 32 n° 1 (01/04/1990)PermalinkSignificance of the remotely sensed thermal infrared measurements obtained over a citrus orchard / J.A. Sobrino in ISPRS Journal of photogrammetry and remote sensing, vol 44 n° 6 (March 1990)Permalink