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Assessment of the influence of flying altitude and scan angle on biophysical vegetation products derived from airborne laser scanning / F. Morsdorf in International Journal of Remote Sensing IJRS, vol 29 n° 5 (March 2008)
[article]
Titre : Assessment of the influence of flying altitude and scan angle on biophysical vegetation products derived from airborne laser scanning Type de document : Article/Communication Auteurs : F. Morsdorf, Auteur ; O. Frey, Auteur ; E. Meier, Auteur ; et al., Auteur Année de publication : 2008 Article en page(s) : pp 1387 - 1406 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] altitude du capteur
[Termes IGN] angle d'incidence
[Termes IGN] angle de visée
[Termes IGN] couvert végétal
[Termes IGN] données laser
[Termes IGN] hauteur des arbres
[Termes IGN] instrumentation Toposys
[Termes IGN] Leaf Area Index
[Termes IGN] modèle numérique de terrain
[Termes IGN] parc naturel
[Termes IGN] plan de vol
[Termes IGN] signal laser
[Termes IGN] Suisse
[Termes IGN] télémétrie laser aéroportéRésumé : (Auteur) Airborne Laser Scanning (ALS) has been established as a valuable tool for the estimation of biophysical vegetation properties such as tree height, crown width, fractional cover and leaf area index (LAI). It is expected that the conditions of data acquisition, such as viewing geometry and sensor configuration influence the value of these parameters. In order to gain knowledge about these different conditions, we test for the sensitivity of vegetation products for viewing geometry, namely flying altitude and scanning (incidence) angle. Based on two methodologies for single tree extraction and derivation of fractional cover and LAI previously developed and published by our group, we evaluate how these variables change with either flying altitude or scanning angle. These are the two parameters which often need to be optimized towards the best compromise between point density and area covered with a single flight line, in order to reduce acquisition costs. Our test-site in the Swiss National Park was sampled with two nominal flying altitudes, 500 and 900 m above ground. Incidence angle and local incidence angle were computed based on the digital terrain model using a simple backward geocoding procedure. We divided the raw laser returns into several different incident angle classes based on the flight path data; the TopoSys Falcon II system used in this study has a maximum scan angle of + 7.15°. We compared the derived biophysical properties from each of these classes with field measurements based on tachymeter measurements and hemispherical photographs, which were geolocated using differential GPS. It was found that with increasing flying height the well-known underestimation of tree height increases. A similar behaviour can be observed for fractional cover; its respective values decrease with higher flying height. The minimum distance between first and last echo increases from 1.2 metres for 500 m AGL to more than 3 metres for 900 m AGL, which does alter return statistics. The behaviour for incidence angles is not so evident, probably due to the small scanning angle of the system used. fCover seems to be most affected by incidence angles, with significantly higher differences for locations further away from nadir. As expected, incidence angle appears to be of higher importance for vegetation density parameters than local incidence angle. Numéro de notice : A2008-081 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160701736349 En ligne : https://doi.org/10.1080/01431160701736349 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29076
in International Journal of Remote Sensing IJRS > vol 29 n° 5 (March 2008) . - pp 1387 - 1406[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-08031 RAB Revue Centre de documentation En réserve L003 Exclu du prêt Analyse spatio-temporelle de l'occupation du sol dans le parc national de Waza entre 1986 et 2001 (Nord Cameroun) / G. Wafo Tabopda in Revue Française de Photogrammétrie et de Télédétection, n° 189 (Mars 2008)
[article]
Titre : Analyse spatio-temporelle de l'occupation du sol dans le parc national de Waza entre 1986 et 2001 (Nord Cameroun) Type de document : Article/Communication Auteurs : G. Wafo Tabopda, Auteur ; Kenji Ose, Auteur ; J.M. Fotsing, Auteur Année de publication : 2008 Article en page(s) : pp 40 - 50 Note générale : Bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] aire protégée
[Termes IGN] analyse spatio-temporelle
[Termes IGN] Cameroun
[Termes IGN] classification par maximum de vraisemblance
[Termes IGN] couvert végétal
[Termes IGN] écosystème
[Termes IGN] image Landsat-ETM+
[Termes IGN] image Landsat-TM
[Termes IGN] occupation du sol
[Termes IGN] parc naturel national
[Termes IGN] savane
[Termes IGN] zone humideRésumé : (Auteur) Le parc national de Waza joue un rôle important dans le maintien des ressources du Nord Cameroun. Cependant, les crises climatiques des années 1970 et la construction du barrage de Maga en 1979 ont provoqué l'assèchement de son réseau hydrographique. Pour réhabiliter son écosystème, le Projet Waza-Logone a été initié au début des années 1990. L'analyse spatio-temporelle de deux images Landsat TM et ETM+ de 1986 et 2001, permet de mettre en évidence les états successifs du couvert végétal ainsi que l'évaluation de sa dynamique dans cette aire protégée du Nord Cameroun. Le couvert végétal connaît une évolution de 52 % entre les deux dates. Cependant, l'analyse des résultats et les requêtes effectuées dans le SIG, autorisent l'identification d'un gradient de déforestation qui révèle les limites des actions concertées et la pression sous-jacente des activités rurales sur les ressources végétales. Copyright SFPT Numéro de notice : A2008-548 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29618
in Revue Française de Photogrammétrie et de Télédétection > n° 189 (Mars 2008) . - pp 40 - 50[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 018-08011 RAB Revue Centre de documentation En réserve L003 Disponible IFN-001-P000586 PER Revue Nogent-sur-Vernisson Salle périodiques 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
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Code-barres Cote Support Localisation Section Disponibilité 080-07121 RAB Revue Centre de documentation En réserve L003 Disponible Characterizing patterns of plant distribution in a southern California salt marsh using remotely sensed topographic and hyperspectral data and local tidal fluctuations / S. Sadro in Remote sensing of environment, vol 110 n° 2 (28/09/2007)
[article]
Titre : Characterizing patterns of plant distribution in a southern California salt marsh using remotely sensed topographic and hyperspectral data and local tidal fluctuations Type de document : Article/Communication Auteurs : S. Sadro, Auteur ; M. Gastil-Buhl, Auteur ; J. Melack, Auteur Année de publication : 2007 Article en page(s) : pp 226 - 239 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] Californie (Etats-Unis)
[Termes IGN] carte de la végétation
[Termes IGN] classification dirigée
[Termes IGN] couvert végétal
[Termes IGN] distribution spatiale
[Termes IGN] données lidar
[Termes IGN] image AVIRIS
[Termes IGN] image hyperspectrale
[Termes IGN] marais salé
[Termes IGN] marée océanique
[Termes IGN] modèle numérique de surfaceRésumé : (Auteur) We used LiDAR topographic data, AVIRIS hyperspectral data, and locally measured tidal fluctuations to characterize patterns of plant distribution within a southern California salt marsh (Carpinteria Salt Marsh (CSM)). LiDAR data required ground truthing and correction before they were suitable for use. Twenty to forty percent of the uncertainty associated with LiDAR was due to variance in the elevation of the target surface, the balance was attributed to error inherent in the LiDAR system. The incidence of LiDAR penetration of plant canopy cover (i.e., registration of ground elevation) was only three percent. The depth of LiDAR penetration into the plant canopy varied according to plant species composition; plant species-specific corrections significantly improved LiDAR accuracy (58% reduction in overall uncertainty) and with the use of ground-based surveys, reduced overall RMSE to an average of 6.3 cm in vegetated areas. A supervised classification of AVIRIS data was used to generate a vegetation map with six classification types; overall classification accuracy averaged 59% with a kappa coefficient of 0.40. The vegetation classification map was overlaid with a LiDAR-based digital elevation model (DEM) to compute elevation distributions and frequencies of tidal inundation. The average elevations of the dominant plant classifications found in CSM (e.g., Salicornia virginica, Jaumea carnosa, and salt-grass mix, a mixture of multiple marsh plant species) occurred within a 17 cm range, a vertical change that resulted in a 7% difference in the period of tidal inundation. Numéro de notice : A2007-150 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2007.02.024 En ligne : https://doi.org/10.1016/j.rse.2007.02.024 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28513
in Remote sensing of environment > vol 110 n° 2 (28/09/2007) . - pp 226 - 239[article]Estimation of vegetation parameter for modelling soil erosion using linear spectral mixture analysis of Landsat ETM data / A.M. DE Asis in ISPRS Journal of photogrammetry and remote sensing, vol 62 n° 4 (September 2007)
[article]
Titre : Estimation of vegetation parameter for modelling soil erosion using linear spectral mixture analysis of Landsat ETM data Type de document : Article/Communication Auteurs : A.M. DE Asis, Auteur ; K. Omasa, Auteur Année de publication : 2007 Article en page(s) : pp 309 - 324 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse linéaire des mélanges spectraux
[Termes IGN] classification pixellaire
[Termes IGN] couvert végétal
[Termes IGN] données de terrain
[Termes IGN] érosion
[Termes IGN] estimation statistique
[Termes IGN] image Landsat-ETM+
[Termes IGN] image Quickbird
[Termes IGN] modèle physique
[Termes IGN] modèle RUSLERésumé : (Auteur) Soil conservation planning often requires estimates of soil erosion at a catchment or regional scale. Predictive models such as Universal Soil Loss Equation (USLE) and its subsequent Revised Universal Soil Loss Equation (RUSLE) are useful tools to generate the quantitative estimates necessary for designing sound conservation measures. However, large-scale soil erosion model-factor parameterization and quantification is difficult due to the costs, labor and time involved. Among the soil erosion parameters, the vegetative cover or C factor has been one of the most difficult to estimate over broad geographic areas. The C factor represents the effects of vegetation canopy and ground covers in reducing soil loss. Traditional methods for the extraction of vegetation information from remote sensing data such as classification techniques and vegetation indices were found to be inaccurate. Thus, this study presents a new approach based on Spectral Mixture Analysis (SMA) of Landsat ETM data to map the C factor for use in the modeling of soil erosion. A desirable feature of SMA is that it estimates the fractional abundance of ground cover and bare soils simultaneously, which is appropriate for soil erosion analysis. Hence, we estimated the C factor by utilizing the results of SMA on a pixel-by-pixel basis. We specifically used a linear SMA (LSMA) model and performed a minimum noise fraction (MNF) transformation and pixel purity index (PPI) on Landsat ETM image to derive the proportion of ground cover (vegetation and non-photosynthetic materials) and bare soil within a pixel. The end-members were selected based on the purest pixels found using PPI with reference to very high-resolution QuickBird image and actual field data. Results showed that the C factor value estimated using LSMA correlated strongly with the values measured in the field. The correlation coefficient (r) obtained was 0.94. A comparative analysis between NDVI- and LSMA-derived C factors also proved that the latter produced a more detailed spatial variability, as well as generated more accurate erosion estimates when used as input to RUSLE model. The QuickBird image coupled with field data was used in the validation of results. Copyright ISPRS Numéro de notice : A2007-430 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2007.05.013 En ligne : https://doi.org/10.1016/j.isprsjprs.2007.05.013 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28793
in ISPRS Journal of photogrammetry and remote sensing > vol 62 n° 4 (September 2007) . - pp 309 - 324[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-07061 SL Revue Centre de documentation Revues en salle Disponible Land surface emissivity retrieval from combined mid-infrared and thermal infrared data of MSG-SEVIRI / G.M. Jiang in Remote sensing of environment, vol 105 n° 4 (30/12/2006)PermalinkQuantifying spatial heterogeneity at the landscape scale using variogram models / S. Garrigues in Remote sensing of environment, vol 103 n° 1 (15 July 2006)PermalinkAcquisition de connaissances pour la simulation en immersion (ACSI) / D. Sebastien (2006)PermalinkPermalinkCanopy directional emissivity: comparison between models / J.A. Sobrino in Remote sensing of environment, vol 99 n° 3 (30/11/2005)PermalinkQuantitative classification as a tool to show change in an urbanizing watershed / W.B. Clapham in International Journal of Remote Sensing IJRS, vol 26 n° 22 (November 2005)PermalinkLAI retrieval from multiangular image classification and inversion of a ray tracing model / R. Casa in Remote sensing of environment, vol 98 n° 4 (30/10/2005)PermalinkA simple and effective radiometric correction method to improve landscape change detection across sensors and across time / X. Chen in Remote sensing of environment, vol 98 n° 1 (30/09/2005)PermalinkUtilisation des images satellitaires Spot pour la cartographie des types de peuplements de la forêt de la Mamora (Maroc) / Abderrahman Aafi in Revue Française de Photogrammétrie et de Télédétection, n° 178 (Septembre 2005)PermalinkEmissivity 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)Permalink