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Evaluating airborne hyperspectral imagery for rangeland assessment in south Texas / James H. Everitt in Geocarto international, vol 19 n° 3 (September - November 2004)
[article]
Titre : Evaluating airborne hyperspectral imagery for rangeland assessment in south Texas Type de document : Article/Communication Auteurs : James H. Everitt, Auteur ; C. Yang, Auteur ; M.R. Davis, Auteur Année de publication : 2004 Article en page(s) : pp 23 - 31 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] bande visible
[Termes IGN] composition colorée
[Termes IGN] ERDAS Imagine
[Termes IGN] flore locale
[Termes IGN] image hyperspectrale
[Termes IGN] occupation du sol
[Termes IGN] rayonnement proche infrarouge
[Termes IGN] réflectance spectrale
[Termes IGN] Texas (Etats-Unis)Résumé : (Auteur) Airborne hyperspectral imagery was evaluated for differentiating among rangeland ecological variables on two range sites (tight sandy loam and shallow ridge) on south Texas rangelands. Field spectroradiometric reflectance measurements made on dominant vegetation (plant species and vegetation mixtures) and soil land-use types on the two sites identified six wavelengths [five visible and one near-infrared (NIR)] where significant spectral differences occurred among the parameters. The spectral bands that corresponded to these wavelengths were extracted from the 128-band hyperspectral images obtained of each site and used to develop false color composites that were subjected to computer classifications and accuracy assessments. The bands selected for the composites included the green (498.9 nm), yellow-green (549.7 nm), orange (629.6 nm), red (651.3 nm), dark red (680.4 nm), and NIR (825.5 tim). Accuracy assessments performed on the classification maps of four false color composites of the tight sandy loam site had overall accuracies ranging from 76% to 85%; the highest accuracy was obtained from the composite made up of the NIR, red, and yellow-green bands. Accuracy assessments performed on the classification maps of three composites of the shallow ridge site had overall accuracies ranging from 74% to 77%; the highest accuracy was acquired from a composite comprised of the NIR, orange, and yellow-green bands. Overall accuracies were considered good and indicate that several band combinations can be used successfully to differentiate among, rangeland parameters in southern Texas. Key Words: remote sensing, hyperspectral imagery, reflectance, false color composite imagery, accuracy assessment. Numéro de notice : A2004-478 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106040408542314 Date de publication en ligne : 02/01/2008 En ligne : https://doi.org/10.1080/10106040408542314 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26996
in Geocarto international > vol 19 n° 3 (September - November 2004) . - pp 23 - 31[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 059-04031 RAB Revue Centre de documentation En réserve L003 Disponible Monitoring surface soil moisture in post-harvest rice areas using C-band radar imagery in NorthEast Thailand / S. Kaojarern in Geocarto international, vol 19 n° 3 (September - November 2004)
[article]
Titre : Monitoring surface soil moisture in post-harvest rice areas using C-band radar imagery in NorthEast Thailand Type de document : Article/Communication Auteurs : S. Kaojarern, Auteur ; Thuy Le Toan, Auteur ; M.W. Davidson, Auteur Année de publication : 2004 Article en page(s) : pp 61 - 71 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] agriculture
[Termes IGN] bande C
[Termes IGN] humidité du sol
[Termes IGN] image ERS-SAR
[Termes IGN] image radar
[Termes IGN] image Radarsat
[Termes IGN] rizière
[Termes IGN] seuillage d'image
[Termes IGN] surveillance agricole
[Termes IGN] surveillance météorologique
[Termes IGN] ThaïlandeRésumé : (Auteur) The objective of this study is to estimate the residual surface soil moisture of rice fields after harvesting, in Northeast Thailand, using Cband SAR images. Such information is use 1 to determine possibilities of cultivating additional shortcycle crops after the harvesting of the main rice crop. To accomplish this objective this study exploits three Cband SAR images acquired over the test area along with simultaneous ground measurements collected in support of analysis of the SAR images. The main parameters measured on the ground were: the volumetric moisture content of the soil using time domain reflectrometry (TDR), the surface roughness, using profile data, and residue cover. Other field environmental factors that might affect radar backscattering, including the topography of rice terraces (elevation, slope, and aspect), bund height between rice fields, soil types, and density of sparse tree stands were also acquired and registered to the image data. Before the analysis, the SAR images were calibrated, registered, and then filtered using multitemporal and spatial filters to reduce variability of the radar backscattering coefficient due to speckle. The measured soil moisture values were then correlated with the radar backscattering coefficients of the experimental plots and the results interpreted in terms of the main environmental factors. Varying residue cover and field aspect angles were found to significantly affect the relationship between radar backscatter and soil moisture content and therefore had to be taken into account before inverting the image data into soil moisture maps. Overall it was found that two soil moisture classes could reliably be separated using the SAR images, and that soil moisture maps could be obtained through a simple inversion technique based on applying a threshold to the SAR images. Analyses of these resulting moisture maps indicate that SAR data is useful to monitor and map surface soil moisture in rice fields after harvest. Numéro de notice : A2004-479 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106040408542319 Date de publication en ligne : 02/01/2008 En ligne : https://doi.org/10.1080/10106040408542319 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26997
in Geocarto international > vol 19 n° 3 (September - November 2004) . - pp 61 - 71[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 059-04031 RAB Revue Centre de documentation En réserve L003 Disponible Use of hyperspectral derivative ratios in the red-edge region to identify plant stress responses to gas leaks / K.L. Smith in Remote sensing of environment, vol 92 n° 2 (15/08/2004)
[article]
Titre : Use of hyperspectral derivative ratios in the red-edge region to identify plant stress responses to gas leaks Type de document : Article/Communication Auteurs : K.L. Smith, Auteur ; M.D. Steven, Auteur ; J.J. Colls, Auteur Année de publication : 2004 Article en page(s) : pp 207 - 217 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] bande visible
[Termes IGN] blé (céréale)
[Termes IGN] canalisation
[Termes IGN] feuille (végétation)
[Termes IGN] gaz
[Termes IGN] herbe
[Termes IGN] image hyperspectrale
[Termes IGN] oxygène (O²)
[Termes IGN] pollution
[Termes IGN] rayonnement proche infrarouge
[Termes IGN] réflectance végétale
[Termes IGN] végétationRésumé : (Auteur) Hyperspectral features in the red-edge region were tested as an index of plant stress responses to soil -oxygen depletion. The aim was to provide the basis for a warning system to identify natural gas leakage by the spectral responses of plants growing in the affected soil.
Elevated concentrations of natural gas in the soil atmosphere were used to deplete oxygen concentrations around the roots of grass, wheat (Hordeum vulgare cv Claire) and bean (Vicia faba cv Clipper) growing in a field facility. Visible symptoms due to the natural gas included reduced growth of the plants and chlorosis of the leaves.
Spectral responses included increased reflectance in the visible wavelengths and decreased reflectance in the near infra-red. Derivative analysis identified features within the red-edge at 720-730 and 702 nm. Ratios of the magnitude of the derivative at 725 to that at 702 nm were less in areas where gas was present. This ratio enabled identification of stress due to gas leakage up to 7 days before visible symptoms were observed and also at the edges of gassed plots where visible symptoms were not expressed. The technique was able to identify stress responses to long-term leaks in all the crops tested but to short-term leaks only in grass. This study therefore suggests that under appropriate conditions remote sensing could be used to detect pipeline gas leaks from decreases in the ratio of peaks within the red-edge.Numéro de notice : A2004-334 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2004.06.002 En ligne : https://doi.org/10.1016/j.rse.2004.06.002 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26861
in Remote sensing of environment > vol 92 n° 2 (15/08/2004) . - pp 207 - 217[article]
[article]
Titre : Meteosat second generation becomes operational Type de document : Article/Communication Auteurs : W. Schumann, Auteur ; R. Oremus, Auteur ; S. Rota, Auteur ; J. Kerkmann, Auteur Année de publication : 2004 Article en page(s) : pp 15 - 21 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] bande infrarouge
[Termes IGN] bande visible
[Termes IGN] données météorologiques
[Termes IGN] image MSG
[Termes IGN] météorologie
[Termes IGN] MétéoSat seconde génération
[Termes IGN] secteur spatialRésumé : (Auteur) A series of four Meteosat Second Generation (MSG) satellites will provide more comprehensive and more frequent data to meteorologists and climate-monitoring scientists for at least the next 14 years. They will bring about a step change in the accuracy of our weather forecasting systems, with considerable benefits for people both in Europe and further afield. These four geostationary satellites are being developed based on the combined expertise of ESA and EUMETSAT (the European Organisation for the Exploitation of Meteorological Satellites). With a thorough understanding of users' needs, EUMETSAT is making a major investment in the overall programme, including development of the ground segment, procurement of the launchers and follow-on satellites and operation of the MSG system from its own Mission Control Centre in Dormstadt, Germany. Numéro de notice : A2004-437 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans En ligne : http://www.esa.int/esapub/bulletin/bulletin119/bul119_chap2.pdf Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26957
in ESA bulletin > n° 119 (August 2004) . - pp 15 - 21[article]A phase signature for detecting wet subsurface structures using polarimetric L-band SAR / Y. Lasne in IEEE Transactions on geoscience and remote sensing, vol 42 n° 8 (August 2004)
[article]
Titre : A phase signature for detecting wet subsurface structures using polarimetric L-band SAR Type de document : Article/Communication Auteurs : Y. Lasne, Auteur ; P. Paillou, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 1683 - 1694 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] bande L
[Termes IGN] dune
[Termes IGN] eau souterraine
[Termes IGN] équation intégrale
[Termes IGN] humidité du sol
[Termes IGN] image AIRSAR
[Termes IGN] paléosol
[Termes IGN] phase
[Termes IGN] sable
[Termes IGN] simulation numérique
[Termes IGN] traitement du signal
[Termes IGN] zone arideRésumé : (Auteur) In this paper, we investigate the ability of L-band synthetic aperture radar (SAR) systems to penetrate soils to retrieve information about subsurface wet structures. Our experiment site, the Pyla dune, is a bare sandy area allowing high radar penetration and known to have large wet subsurface structures (paleosoils) at varying depths. Buried paleosoils, which act as moisture tanks, are detectable with radar, since they present a high permittivity due to their water content. By analyzing airborne polarimetric SAR data, we established that a phase signature is correlated to the buried wet palesoils: a phase difference of 23° between the horizontal (HH) and vertical (V V) channels was clearly observed. It allows detection of the paleosoil down to a larger depth (5.2 m) than when only considering HH and HV amplitude signals (3.5 m). In order to confirm this result, field measurements were performed that led to the same observed phase difference. We could fit our observations to the semiempirical model proposed by Oh and Sarabandi, and we reproduced the observed phenomenon using a two-layer integral equation method (IEM) model of the Pyla dune, which was completed by finite-difference time-domain (FDTD) numerical simulations. We show that the soil moisture significantly influences the radar response in terms of phase difference between the copolarised modes. Our study also shows that the single-scattering IEM model reproduces the observed phase difference fairly well for a natural outdoor site when combined to FDTD simulation results. This phase signature could be used as a new tool to map subsurface moisture in arid regions. Numéro de notice : A2004-428 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2004.830645 En ligne : https://doi.org/10.1109/TGRS.2004.830645 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26955
in IEEE Transactions on geoscience and remote sensing > vol 42 n° 8 (August 2004) . - pp 1683 - 1694[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-04081 RAB Revue Centre de documentation En réserve L003 Disponible Mapping vegetation in a heterogeneous mountain rangeland using Landsat data: an alternative method to define and classify land-cover units / A.M. Cingolani in Remote sensing of environment, vol 92 n° 1 (15 July 2004)PermalinkNoise over water surfaces in Landsat TM images / J.E. Nichol in International Journal of Remote Sensing IJRS, vol 25 n° 11 (June 2004)PermalinkEvaluation of the MODIS LAI at coniferous forest site in Finland / Y. Wang in Remote sensing of environment, vol 91 n° 1 (15/05/2004)PermalinkEstimation of leaf water status to monitor the risk of forest fires by using remotely sensed data / M. Maki in Remote sensing of environment, vol 90 n° 4 (30/04/2004)PermalinkRefinement of wavelength calibrations of hyperspectral imaging data using a spectrum-machine technique / B.C. Gao in Remote sensing of environment, vol 90 n° 4 (30/04/2004)PermalinkAtmospheric correction of Advanced Very High Resolution Radiometer imagery / Mhd. Suhyb Salama in International Journal of Remote Sensing IJRS, vol 25 n° 7 (April 2004)PermalinkSeaWIFS validation in European coastal waters using optical and bio-geochemical measurements / S.J. Lavender in International Journal of Remote Sensing IJRS, vol 25 n° 7 (April 2004)PermalinkCloud screening in IRS-P4 OCM satellite data: potential of spatial coherence method in the absence of thermal channel information / S.K. Nair in Remote sensing of environment, vol 90 n° 2 (30/03/2004)PermalinkIntegrating imaging spectroscopy and neural networks to map grass quality in the Kruger National Park, South Africa / Onisimo Mutanga in Remote sensing of environment, vol 90 n° 1 (15/03/2004)PermalinkEstimating fractional snow cover from MODIS using the normalized difference snow index / V.V. Salomonson in Remote sensing of environment, vol 89 n° 3 (15/02/2004)Permalink