Descripteur
Documents disponibles dans cette catégorie (49)
Ajouter le résultat dans votre panier Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
Use of a Kalman filter for the retrieval of surface BRDF coefficients with a time-evolving model based on the ECOCLIMAP land cover classification / O. Samain in Remote sensing of environment, vol 112 n° 4 (15/04/2008)
[article]
Titre : Use of a Kalman filter for the retrieval of surface BRDF coefficients with a time-evolving model based on the ECOCLIMAP land cover classification Type de document : Article/Communication Auteurs : O. Samain, Auteur ; J.L. Roujeau, Auteur ; Bernhard Geiger, Auteur Année de publication : 2008 Article en page(s) : pp 1337 - 1346 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] Afrique occidentale
[Termes IGN] cohérence des données
[Termes IGN] distribution du coefficient de réflexion bidirectionnelle BRDF
[Termes IGN] filtre de Kalman
[Termes IGN] image SPOT-Végétation
[Termes IGN] image Terra-MODIS
[Termes IGN] occupation du sol
[Termes IGN] réflectance de surface
[Termes IGN] réflectance directionnelle
[Termes IGN] variation saisonnièreRésumé : (Auteur) The goal of this study is to demonstrate the asset in using a Kalman filter to improve the spatial coherence and time consistency of surface Bidirectional Reflectance Distribution Function (BRDF) and albedo retrievals from moderate resolution sensor data sets. For this purpose, we use a simple surface model describing BRDF seasonal evolution for the land cover classes of the ECOCLIMAP database. The application of temporal composition windows used so far for BRDF retrieval is limited in regions characterized by a high frequency of cloud coverage, which induces a lot of gaps in the temporal series. Instead, the present method ensures a continuous production of surface BRDF parameters thanks to the Kalman filter recursive data processing. An application of the method is performed with SPOT/VEGETATION data over the western Africa equatorial region for the year 2003. Compared to presently available products from VEGETATION and MODIS instruments, this new approach allows to fill the gaps and improves the retrieved parameters time consistency. Another interesting possibility of the Kalman filter is the production of surface biophysical variables in quasi-real-time for applications that require a frequent update of the surface parameters. Copyright Elsevier Numéro de notice : A2008-092 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2007.07.007 En ligne : https://doi.org/10.1016/j.rse.2007.07.007 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29087
in Remote sensing of environment > vol 112 n° 4 (15/04/2008) . - pp 1337 - 1346[article]Correction of laser scanning intensity data: data and model-driven approaches / Bernhard Höfle in ISPRS Journal of photogrammetry and remote sensing, vol 62 n° 6 (November-December 2007)
[article]
Titre : Correction of laser scanning intensity data: data and model-driven approaches Type de document : Article/Communication Auteurs : Bernhard Höfle, Auteur ; Norbert Pfeifer, Auteur Année de publication : 2007 Article en page(s) : pp 415 - 433 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] correction du signal
[Termes IGN] intensité lumineuse
[Termes IGN] réflectance de surface
[Termes IGN] signal laser
[Termes IGN] télémètre laser à balayage
[Termes IGN] traitement du signalRésumé : (Auteur) Most airborne and terrestrial laser scanning systems additionally record the received signal intensity for each measurement. Multiple studies show the potential of this intensity value for a great variety of applications (e.g. strip adjustment, forestry, glaciology), but also state problems if using the original recorded values. Three main factors, a) spherical loss, b) topographic and c) atmospheric effects, influence the backscatter of the emitted laser power, which leads to a noticeably heterogeneous representation of the received power. This paper describes two different methods for correcting the laser scanning intensity data for these known influences resulting in a value proportional to the reflectance of the scanned surface. The first approach – data-driven correction – uses predefined homogeneous areas to empirically estimate the best parameters (least-squares adjustment) for a given global correction function accounting for all range-dependent influences. The second approach – model-driven correction – corrects each intensity independently based on the physical principle of radar systems. The evaluation of both methods, based on homogeneous reflecting areas acquired at different heights in different missions, indicates a clear reduction of intensity variation, to 1/3.5 of the original variation, and offsets between flight strips to 1/10. The presented correction methods establish a great potential for laser scanning intensity to be used for surface classification and multi-temporal analyses. Copyright ISPRS Numéro de notice : A2007-528 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2007.05.008 En ligne : https://doi.org/10.1016/j.isprsjprs.2007.05.008 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28891
in ISPRS Journal of photogrammetry and remote sensing > vol 62 n° 6 (November-December 2007) . - pp 415 - 433[article]Réservation
Réserver ce documentExemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité 081-07081 SL Revue Centre de documentation Revues en salle Disponible Variability of fire-induced changes in MODIS surface reflectance by land-cover type in Borneo / Jukka Miettinen in International Journal of Remote Sensing IJRS, vol 28 n° 21-22 (November 2007)
[article]
Titre : Variability of fire-induced changes in MODIS surface reflectance by land-cover type in Borneo Type de document : Article/Communication Auteurs : Jukka Miettinen, Auteur Année de publication : 2007 Article en page(s) : pp 4967 - 4984 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] analyse discriminante
[Termes IGN] Bornéo, île de
[Termes IGN] couvert végétal
[Termes IGN] image Aqua-MODIS
[Termes IGN] image Terra-MODIS
[Termes IGN] incendie de forêt
[Termes IGN] occupation du sol
[Termes IGN] réflectance de surface
[Termes IGN] réflectance spectrale
[Termes IGN] variabilitéRésumé : (Auteur) This study investigates fire-induced spectral changes detected by the Moderate Resolution Imaging Spectroradiometer (MODIS) in different land-cover types in Borneo. Linear discriminant analysis is used to determine the most powerful band combinations among the MODIS reflective bands for discrimination between burnt and unburnt areas in each land-cover type. The results show that the nature of fire-induced changes is dependent on pre-fire vegetation characteristics in this region. Bands 1 (0.64 um), 2 (0.86 um), and 7 (2.14 um) are found to be the most sensitive bands in land-cover types dominated by green vegetation, and consequently indices or combinations of indices using these three bands are potentially effective for burnt-area detection in the majority of areas. In land-cover types dominated by dry vegetation and soil, MODIS band 5 (1.24 um) alone showed the greatest statistical separability and could not be significantly improved by any multiband index. Copyright Taylor & Francis Numéro de notice : A2007-492 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160701268962 En ligne : https://doi.org/10.1080/01431160701268962 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28855
in International Journal of Remote Sensing IJRS > vol 28 n° 21-22 (November 2007) . - pp 4967 - 4984[article]Réservation
Réserver ce documentExemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité 080-07121 RAB Revue Centre de documentation En réserve L003 Disponible Dual-frequency altimeter signal from Envisat on the Amery ice-shelf / Pascal Lacroix in Remote sensing of environment, vol 109 n° 3 (15 August 2007)
[article]
Titre : Dual-frequency altimeter signal from Envisat on the Amery ice-shelf Type de document : Article/Communication Auteurs : Pascal Lacroix, Auteur ; Benoit Legrésy, Auteur ; et al., Auteur ; et al., Auteur Année de publication : 2007 Article en page(s) : pp 285 - 294 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] altimétrie par radar
[Termes IGN] Antarctique
[Termes IGN] bande S
[Termes IGN] calotte glaciaire
[Termes IGN] crevasse
[Termes IGN] écho radar
[Termes IGN] épaisseur de la glace
[Termes IGN] image Envisat-AATSR
[Termes IGN] réflectance de surface
[Termes IGN] réflexion spéculaire
[Termes IGN] traitement du signal
[Termes IGN] variation saisonnièreRésumé : (Auteur) In Antarctica, radar altimeter measurements are sensitive to dielectric and penetration properties of the sensed medium (snow) such that the spacecraft's altitude can be biased. Since 2002, relatively low frequency radar measurements over the Amery Ice Shelf, east Antarctica, have been acquired using the Envisat dual frequency altimeter at S (3.2 GHz) and Ku (13.6 GHz) bands, which penetrate a few meters into the firn. The altimeter signal is however modified in summer by the presence of snowfilled crevasses. Indeed, the specularity of the snow surfaces in summer makes the altimetric signal sensitive mostly to nadir echoes, that increases the ratio between the crevasse signal and the surrounding ice-shelf signal at nadir. Crevasses are distinguished by differences in backscattering behavior compared with the surrounding ice-shelf signal. Crevasses are characterized by a strong backscatter coefficient at Ku band and anomalies in the S band altitude estimation. These two characteristics make snowfilled crevasses detectable by the dual frequency altimeter of Envisat. We first retrieve the geometric properties of the crevasses using a hyperbolic shape function, created by strong crevasse backscatter in the Ku waveform measurements. From this retrieved crevasse signal and further waveform analysis, we assess the properties of the snow surface and its sub-surface. The crevasse, due to its small size compared to the altimeter footprint, is found to be an excellent target to study snow properties of the ice-shelf. The anomalies in the S band altitude measurements over crevasses can then be explained by the presence of a double echo in the S band waveforms. This echo is attributed to a reflection at the base of the snowbridge, where we see evidence of sub-surface echos in the individual altimeter waveforms. Based on this observation, a methodology is developed to estimate the thickness of the snowbridge. We calculate the penetration depths in the summer snow surface of the Amery at Ku band, that is found to be around 6 m. Copyright Elsevier Numéro de notice : A2007-312 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2007.01. En ligne : https://doi.org/10.1016/j.rse.2007.01.007 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28675
in Remote sensing of environment > vol 109 n° 3 (15 August 2007) . - pp 285 - 294[article]Spectral calibration and atmospheric correction of ultra-fine spectral and spatial resolution remote sensing data: Application to CASI-1500 data / L. Guanter in Remote sensing of environment, vol 109 n° 1 (12 July 2007)
[article]
Titre : Spectral calibration and atmospheric correction of ultra-fine spectral and spatial resolution remote sensing data: Application to CASI-1500 data Type de document : Article/Communication Auteurs : L. Guanter, Auteur ; V. Estelles, Auteur ; J. Moreno, Auteur Année de publication : 2007 Article en page(s) : pp 54 - 65 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] aérosol
[Termes IGN] Castille-La Manche
[Termes IGN] correction atmosphérique
[Termes IGN] épaisseur optique
[Termes IGN] étalonnage spectral
[Termes IGN] image CASI
[Termes IGN] réflectance de surfaceRésumé : (Auteur) Imaging spectrometers operating in the solar spectrum measure the upwelling reflected solar radiation, and are an important tool in the bio/geochemical characterization of the Earth system. Surface reflectance is usually the starting point for the retrieval of biophysical parameters from remote measurements. Reliable radiometric and spectral calibrations and accurate atmospheric correction are mandatory in the interpretation of the surface reflectance. A complete surface reflectance retrieval scheme specifically designed for ultra-fine spectral resolution (bandwidth from 10 to 2 nm) and spatial resolution (pixel size less than 10 m) imaging spectrometers is presented in this work. The assessment of the spectral calibration is coupled to the removal of the atmospheric distortion so that maps of surface reflectance are derived, as well as columnar water vapor (CWV) maps, estimations of aerosol optical thickness (AOT) and updated sensor gain coefficients and spectral calibration. Radiative transfer calculations are performed by an optimized version of the MODTRAN4 code, which is run before processing each image. The method is tested against Compact Airborne Spectrographic Imager (CASI) 1500 images acquired during the ESA SENtinel-2 and FLuorescence EXperiment (SEN2FLEX) campaigns held in the Barrax (La Mancha, Spain) study site during June and July 2005. A peak-to-peak spectral shift variation of up to 2.3 nm is detected in CASI. Concerning atmospheric products and surface reflectance retrievals, an extensive validation is performed using ground-based measurements. A good correlation between ground measurements and CASI-derived AOT and CWV is found, with a Pearson correlation coefficient r2 up to 0.71 and 0.74, respectively. The subsequent surface reflectance retrievals also hold a good correspondence with ground-based measurements. Copyright Elsevier Numéro de notice : A2007-301 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2006.12.005 En ligne : https://doi.org/10.1016/j.rse.2006.12.005 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28664
in Remote sensing of environment > vol 109 n° 1 (12 July 2007) . - pp 54 - 65[article]Estimating atmospheric transmission and surface reflectance from a glint-contaminated spectral image / W. Philpot in IEEE Transactions on geoscience and remote sensing, vol 45 n° 2 (February 2007)PermalinkValidation of MERIS Level-2 products in the Baltic Sea, the Namibian coastal area and the Atlantic Ocean / T. Ohde in International Journal of Remote Sensing IJRS, vol 28 n°3-4 (February 2007)PermalinkComparison of space borne radar altimetry and airborne laser altimetry over sea ice in the Fram Strait / K.A. Giles in International Journal of Remote Sensing IJRS, vol 27 n°15-16 (August 2006)PermalinkUtilizing calibrated GPS reflected signals to estimate soil reflectivity and dielectric constant: results from SMEX02 / S.J. Katzberg in Remote sensing of environment, vol 100 n° 1 (15/01/2006)PermalinkAn inverse radiative transfer model to extract ground spectral reflectance of urban areas / Sophie Lacherade (2006)PermalinkA method for the surface reflectance retrieval from PROBA/CHRIS data over land: application to ESA SPARC campaigns / L. Guanter in IEEE Transactions on geoscience and remote sensing, vol 43 n° 12 (December 2005)PermalinkPrototyping a global algorithm for systematic fire-affected area mapping using MODIS time series data / D.P. Roy in Remote sensing of environment, vol 97 n° 2 (30/07/2005)PermalinkGround-penetrating radar measurement of crop and surface water content dynamics / G. Serbin in Remote sensing of environment, vol 96 n° 1 (15/05/2005)PermalinkQuality assessment and improvement of temporally composite products of remote sensed imagery by combination of Vegetation 1 and 2 images / Olivier Hagolle in Remote sensing of environment, vol 94 n° 2 (30/01/2005)PermalinkUsing angular and spectral shape similarity constraints to improve MISR aerosol and surface retrievals over land / D. Diner in Remote sensing of environment, vol 94 n° 2 (30/01/2005)Permalink