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An autonomous above-water system for the validation of ocean color radiance data / G. Ziborni in IEEE Transactions on geoscience and remote sensing, vol 42 n° 2 (February 2004)
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Titre : An autonomous above-water system for the validation of ocean color radiance data Type de document : Article/Communication Auteurs : G. Ziborni, Auteur ; F. Melin, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 401 - 415 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] Adriatique, mer
[Termes IGN] analyse comparative
[Termes IGN] eaux côtières
[Termes IGN] étalonnage radiométrique
[Termes IGN] exitance spectrale
[Termes IGN] image Aqua-MODIS
[Termes IGN] image Envisat-MERIS
[Termes IGN] image Seawifs
[Termes IGN] luminance lumineuse
[Termes IGN] photométrie
[Termes IGN] radianceRésumé : (Auteur) An operational system for autonomous above-water radiance measurements, called the SeaWiFS Photometer Revision for Incident Surface Measurements (SeaPRISM), was deployed at the Acqua Alta Oceanographic Tower in the northern Adriatic Sea and used for the validation of remote sensing radiometric products in coastal waters. The SeaPRISM data were compared with simultaneous data collected from an independent in-water system for a wide variety of sun elevations along with different atmospheric, seawater, and sea state conditions. The average absolute differences between the above- and in-water determinations of water-leaving radiances (computed linearly) were less than 4.5% in the 412-555-nm spectral interval. A similar comparison for normalized water-leaving radiances showed average absolute differences less than 5.1%. The comparison between normalized water-leaving radiances computed from remote sensing and SeaPRISM matchup data, showed absolute spectral average (linear) differences of 17.0%, 22.1%, and 20.8% for SeaWiFS, MODIS, and MERIS, respectively. The results, in keeping with those produced by independent in-water systems, suggest the feasibility of operational coastal networks of autonomous above-water radiometers deployed on fixed platforms (towers, lighthouses, navigation aids, etc.) to support ocean color validation activities. Numéro de notice : A2004-137 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2003.821064 En ligne : https://doi.org/10.1109/TGRS.2003.821064 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26664
in IEEE Transactions on geoscience and remote sensing > vol 42 n° 2 (February 2004) . - pp 401 - 415[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-04021 RAB Revue Centre de documentation En réserve L003 Disponible Phenomenological analysis of simulated signals observed over shaded areas in an urban scene / Christophe Miesch in IEEE Transactions on geoscience and remote sensing, vol 42 n° 2 (February 2004)
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Titre : Phenomenological analysis of simulated signals observed over shaded areas in an urban scene Type de document : Article/Communication Auteurs : Christophe Miesch, Auteur ; Xavier Briottet , Auteur ; Yann H. Kerr, Auteur
Année de publication : 2004 Article en page(s) : pp 434 - 442 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] bande spectrale
[Termes IGN] diffusion du rayonnement
[Termes IGN] image à haute résolution
[Termes IGN] image panchromatique
[Termes IGN] milieu urbain
[Termes IGN] ombre
[Termes IGN] réfraction atmosphérique
[Termes IGN] scène
[Termes IGN] simulation
[Termes IGN] transfert radiatifRésumé : (Auteur) This paper analyzes the signal measured by optical remote sensors when acquiring data over a shaded part of an urban scene. The signal is much lower for this kind of target than for others because there is no direct downward irradiance. Here, a simple urban scene is considered with a shaded area. The signal observed by a high spatial resolution satellite sensor over an ordinary panchromatic band (500-700 nm) is computed thanks to a radiative transfer code [advanced modeling of the atmospheric radiative transfer for inhomogeneous surfaces (Amartis)] capable of dealing with ground topography and heterogeneity. The signal is analyzed, and it appears that environmental effects play a significant role. Moreover, because of the scattering that occurs at shorter wavelengths, it is also shown that a widening of the band to 440 nm sharpens the difference between signals coming from two different ground types (for whose the difference of reflectance is constant and equal to 0.1) by about 10%. This demonstrates that the band widening may be beneficial to observation in shadow, mainly because of scattering effects. A more realistic scene is also considered, in which each part is associated with realistic spectral properties. This simply shows the importance of the thematic in the choice of band, as it determines the effect of the widening. Numéro de notice : A2004-138 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2003.814916 En ligne : https://doi.org/10.1109/TGRS.2003.814916 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26665
in IEEE Transactions on geoscience and remote sensing > vol 42 n° 2 (February 2004) . - pp 434 - 442[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-04021 RAB Revue Centre de documentation En réserve L003 Disponible Systematic corrections of AVHRR image composites for temporal studies / J. Cihlar in Remote sensing of environment, vol 89 n° 2 (30/01/2004)
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Titre : Systematic corrections of AVHRR image composites for temporal studies Type de document : Article/Communication Auteurs : J. Cihlar, Auteur ; R. Latifovic, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 217 - 233 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse comparative
[Termes IGN] correction d'image
[Termes IGN] distribution du coefficient de réflexion bidirectionnelle BRDF
[Termes IGN] image en couleur composée
[Termes IGN] image Landsat-TM
[Termes IGN] image NOAA-AVHRR
[Termes IGN] réflectance végétaleRésumé : (Auteur) For quantitative studies of vegetation dynamics, satellite data need to be corrected for spurious effects. In this study, we have applied several changes to an earlier advanced very high resolution radiometer (AVHRR) processing methodology (ABC3; [Remote Sens. Environ. 60 (1997) 35; J. Geophys. Res.Atmos, 102 (1997) 29625; Can. J. Remote Sens. 23 (1997) 163]), to better represent the various physical processes causing contamination of the AVHRR measurements. These included published recent estimates of the NOAA-11 and NOAA-14 AVHRR calibration trajectories for channels 1 and 2; the best available estimates for the water vapour, aerosol and ozone amounts at the time of AVHRR data acquisition; an improved bidirectional reflectance algorithm that also takes into consideration surface topography; and an improved image screening algorithm for contaminated pixels. Unlike the previous study that compared the composite images to a single-date AVHRR image, we employed coincident TM images to approximate the AVHRR pixel field of view during the data acquisition. Compared to ABC3, the modified procedure ABOV2 was found to improve the accuracy of AVHRR pixel reflectance estimates, both in the sensitivity (slope) of the regression and in r2. The improvements were especially significant in AVHRR channel 1. In comparison with reference values derived from two full TM scenes, the corrected AVHRR surface reflectance estimates had average standard errors values of + 0.009 for AVHRR C1, + 0.019 for C2, and + 0.04 for NDVI; the corresponding r2 values were 0.55, 0.80, and 0.50, respectively. The changes in ABC3V2 were not able to completely remove interannual variability for land cover types with little or no vegetation cover, which would be expected to remain stable over time, and they increased the interannual variability of mixed forest and grassland. These results are attributed to a combination of increased sensitivity to interannual dynamics on one hand, and the inability to remove all sources of noise for barren or sparsely vegetated northern land cover types on the other. Numéro de notice : A2004-025 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2002.06.007 En ligne : https://doi.org/10.1016/j.rse.2002.06.007 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26553
in Remote sensing of environment > vol 89 n° 2 (30/01/2004) . - pp 217 - 233[article]Narrowband-to-broadband albedo conversion for glacier ice and snow: equations based on modeling and ranges of validity of the equations / W. Greuell in Remote sensing of environment, vol 89 n° 1 (15/01/2004)
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Titre : Narrowband-to-broadband albedo conversion for glacier ice and snow: equations based on modeling and ranges of validity of the equations Type de document : Article/Communication Auteurs : W. Greuell, Auteur ; J. Oerlemans, Auteur Année de publication : 2004 Article en page(s) : pp 95 - 105 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] albedo
[Termes IGN] éclairement énergétique
[Termes IGN] erreur moyenne quadratique
[Termes IGN] glace
[Termes IGN] image Landsat-TM
[Termes IGN] image NOAA-AVHRR
[Termes IGN] image Terra-MISR
[Termes IGN] image Terra-MODIS
[Termes IGN] neige
[Termes IGN] réflectance
[Termes IGN] transfert radiatifRésumé : (Auteur) In this paper, we propose equations for narrowband-to-broadband (NTB) albedo conversion for glacier ice and snow for four types of satellite sensors : thematic mapper (TM), advanced very high resolution radiometer (AVHRR), moderate resolution imaging spectroradiometer (MODIS), and multi-angle imaging spectroradiometer (MISR). We do this on the basis of spectral albedos and incident spectral irradiances generated with radiative-transfer models of the (sub)surface (a two-stream model) and the atmosphere, respectively. First, we establish equations for reference values of atmospheric components and the surface elevation. These equations describe measurements with root-mean-square differences of ~0.016. We then show that the "reference equations" also perform well when total ozone and aerosol optical depth are changed with respect to the reference. The negative effect of humidity and elevation variations on the performance of the equations can be eliminated by adding a correction term. We argue that narrowband albedos are much less sensitive to variations in the incident spectral irradiance than broadband albedos. Hence, our conclusions about the effects of variations in atmospheric composition and elevation are also valid for equations for NTB conversion proposed in other papers. Numéro de notice : A2004-010 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2003.10.010 En ligne : https://doi.org/10.1016/j.rse.2003.10.010 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26538
in Remote sensing of environment > vol 89 n° 1 (15/01/2004) . - pp 95 - 105[article]Toward universal broad leaf chlorophyll indices using PROSPECT simulated database and hyperspectral reflectance measurements / G. Le Maire in Remote sensing of environment, vol 89 n° 1 (15/01/2004)
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Titre : Toward universal broad leaf chlorophyll indices using PROSPECT simulated database and hyperspectral reflectance measurements Type de document : Article/Communication Auteurs : G. Le Maire, Auteur ; C. François, Auteur ; Eric Dufrêne, Auteur Année de publication : 2004 Article en page(s) : pp 1 - 28 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] albedo
[Termes IGN] chlorophylle
[Termes IGN] erreur moyenne quadratique
[Termes IGN] feuillu
[Termes IGN] indice de végétation
[Termes IGN] réflectance végétale
[Termes IGN] réseau neuronal artificielRésumé : (Auteur) Fifty-three leaves were randomly sampled on different deciduous tree species, representing a wide range of chlorophyll contents, tree ages, and leaf structural features. Their reflectance was measured between 400 and 800 nm with a 1-nm step, and their chlorophyll content determined by extraction. A larger simulated database (11,583 spectra) was built using the PROSPECT model, in order to test, calibrate, and obtain universal indices, i.e., indices applicable to a wide range of species and leaf structure. To our knowledge, almost all leaf chlorophyll indices published in the literature since 1973 have been tested on both databases. Fourteen canonical types of indices (published ones and new ones) were identified, and their wavelengths calibrated on the simulated database as well as on the experimental database to determine the best wavelengths and, hence, the best performances in chlorophyll estimation for each index types. These indices go from simple reflectance ratios to more sophisticated indices using reflectance first derivatives (using the Savitzky and Golay method). We also tested other nondestructive methods to obtain total chlorophyll concentration: SPAD (Minolta Camera, Osaka, Japan) and neural networks. The validity of the actual PROSPECT model is challenged by our results: Important discordances are found when the indices are calculated with PROSPECT compared to experimental data, especially for some indices and wavelengths. The discordance is even greater when the indices are determined with PROSPECT and applied on the experimental database. A new calibration of PROSPECT is therefore necessary for any study aiming at using simulated spectra to determine or to calibrate indices. The "peak jump" and the multiplepeak feature observed on the first derivative of the reflectances (e.g., in the Red-Edge Inflection Point [REIP] index) has been investigated. It was shown that chlorophyll absorption alone can explain this feature. The peak jump disqualifies the REIP to be a valuable chlorophyll index. A simple modified difference ratio gave the best results among all published indices (cross-validated RMSE 2.1 [ug/cm2 on the experimental database). After calibration on the experimental database, modified Simple Ratio (mSR) and modified Nonnalized Difference (mND) indices gave the best performances (RMSECV = 1. 8 ug/cm2 on the experimental database). The new Double Difference (DD) index, although not the best on the experimental database (RMSECV = 2.9 [ug/cm2), has the best results on the larger simulated database (RMSE = 3.7 gg/cm2 ) and is expected to give good results on larger experimental databases. The best reflectance-based indices give better performances than the current commercial nondestructive device SPAD (RMSECV = 4.5 ug/cm2). In this leaf-level study, the best indices are very near from each other, so that complex methods are useless: REIP-like, neural networks, and derivative-based indices are not necessary and give worst results than simpler properly chosen indices. These conclusions will certainly be different for a canopy-level study, where the derivative-based indices may perform significantly better than the other ones. Numéro de notice : A2004-008 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2003.09.004 En ligne : https://doi.org/10.1016/j.rse.2003.09.004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26536
in Remote sensing of environment > vol 89 n° 1 (15/01/2004) . - pp 1 - 28[article]Hyperspectral monitoring of physiological parameters of wheat during a vegetation period using AVIS data / N. Oppelt in International Journal of Remote Sensing IJRS, vol 25 n° 1 (January 2004)
PermalinkSpectral characteristics and feature selection of hyperspectral remote sensing data / X. Jiang in International Journal of Remote Sensing IJRS, vol 25 n° 1 (January 2004)
PermalinkThe EuroSTARRS airborne campaign in support of the SMOS mission: first results over land surfaces / K. Saleh in International Journal of Remote Sensing IJRS, vol 25 n° 1 (January 2004)
PermalinkVegetation/SPOT: an operational mission for the Earth monitoring, presentation of new standard product / P. Maisongrande in International Journal of Remote Sensing IJRS, vol 25 n° 1 (January 2004)
PermalinkPermalinkBayesian-based subpixel brightness temperature estimation from multichannel infrared GOES radiometer data / S. Cain in IEEE Transactions on geoscience and remote sensing, vol 42 n° 1 (January 2004)
PermalinkCelebrating a decade of the International GPS Service, Workshop & Symposium 2004 / Michael Meindl (2004)
PermalinkGPS based determination of the integrated and spatially distributed water vapor in the troposphere / Marc Troller (2004)
PermalinkPermalinkPermalinkPermalinkPermalinkRapport du directeur sur l'activité et la gestion du Bureau International des Poids et Mesures (BIPM), 1er juillet 2003 - 30 juin 2004 / Bureau international des poids et mesures (2004)
PermalinkPermalinkA study of scattering from an object below a rough surface / Joel T. Johnson in IEEE Transactions on geoscience and remote sensing, vol 42 n° 1 (January 2004)
PermalinkPermalinkThéorie et traitement du signal, 2. Méthodes de base pour l'analyse et le traitement du signal / Messaoud Benidir (2004)
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