Descripteur
Documents disponibles dans cette catégorie (835)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
The electronically steerable flash Lidar : A full waveform scanning system for topographic and ecosystem structure applications / H. Duong in IEEE Transactions on geoscience and remote sensing, vol 50 n° 11 Tome 2 (November 2012)
[article]
Titre : The electronically steerable flash Lidar : A full waveform scanning system for topographic and ecosystem structure applications Type de document : Article/Communication Auteurs : H. Duong, Auteur Année de publication : 2012 Article en page(s) : pp 4809 - 4820 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] Colorado (Etats-Unis)
[Termes IGN] couvert forestier
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] forêt tempérée
[Termes IGN] forêt tropicale
[Termes IGN] forme d'onde pleine
[Termes IGN] hauteur de la végétation
[Termes IGN] Lidar
[Termes IGN] Texas (Etats-Unis)Résumé : (Auteur) The electronically steerable flash lidar (ESFL) is a waveform lidar sensor that incorporates two advances relevant to the design of future spaceborne lidar sensors. The first is a nonmechanical scanner that splits a single incoming beam into a variable number of output beams that can be aligned independently across track; the transmitted beam pattern can be changed up to 60 Hz. The second is a flash focal plane array (FFPA) capable of recording waveforms simultaneously from a 128 x 128 pixel grid with individual footprints spread over multiple pixels. In this paper, the incoming beam was used to illuminate eight 8.4-m footprints which were imaged simultaneously on 12 x 12 pixel subsets of the FFPA. The FFPA digitizes waveforms at a vertical resolution of 75 cm over 41 vertical bins to create waveforms of 30.75-m depth. Multiple waveforms obtained using range-gating were combined for these analyses. ESFL data were collected at Manitou Experimental Forest (MEF), located in the Pikes Peak National Forest, Colorado, USA and the Stephen F. Austin Experimental Forest (AEF), located in the Angelina Forest, Nacogdoches, TX. We evaluated the use of individual pixel-level and aggregated footprint-level waveforms and alternate approaches to define the extent of each footprint in the focal plane array. Using discrete return lidar data as a reference, we evaluated the ability of ESFL lidar to estimate canopy height and compared the two sensors' rates of penetration to the terrain surface. We found the footprint-level waveforms were better suited for use with existing waveform processing techniques, although techniques for processing at the pixel-level appear feasible. Relationships between height estimates from each lidar data set were most closely related when footprint-level ESFL waveforms were calculated after removing pixels that had less than 50% of the maximum energy within that footprint. Regressions between ESFL and reference lidar data estimates - f height explained 84% (AEF) and 85% (MEF) of variance; this study could not say definitively which method yielded the more accurate estimate of height. Numéro de notice : A2012-593 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2012.2193588 Date de publication en ligne : 16/05/2012 En ligne : https://doi.org/10.1109/TGRS.2012.2193588 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32039
in IEEE Transactions on geoscience and remote sensing > vol 50 n° 11 Tome 2 (November 2012) . - pp 4809 - 4820[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 065-2012111B RAB Revue Centre de documentation En réserve L003 Disponible Digital Elevation Model from the best results of different filtering of a LiDAR point cloud / T. Podobnikar in Transactions in GIS, vol 16 n° 5 (October 2012)
[article]
Titre : Digital Elevation Model from the best results of different filtering of a LiDAR point cloud Type de document : Article/Communication Auteurs : T. Podobnikar, Auteur ; Anja Vrecko, Auteur Année de publication : 2012 Article en page(s) : pp 603 - 617 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] filtrage de points
[Termes IGN] modèle numérique de surface
[Termes IGN] semis de pointsRésumé : (Auteur) The LiDAR point clouds captured with airborne laser scanning provide considerably more information about the terrain surface than most data sources in the past. This rich information is not simply accessed and convertible to a high quality digital elevation model (DEM) surface. The aim of the study is to generate a homogeneous and high quality DEM with the relevant resolution, as a 2.5D surface. The study is focused on extraction of terrain (bare earth) points from a point cloud, using a number of different filtering techniques accessible by selected freeware. The proposed methodology consists of: (1) assessing advantages/disadvantages of different filters across the study area, (2) regionalization of the area according to the most suitable filtering results, (3) data fusion considering differently filtered point clouds and regions, and (4) interpolation with a standard algorithm. The resulting DEM is interpolated from a point cloud fused from partial point clouds which were filtered with multiscale curvature classification (MCC), hierarchical robust interpolation (HRI), and the LAStools filtering. An important advantage of the proposed methodology is that the selected landscape and datasets properties have been more holistically studied, with applied expert knowledge and automated techniques. The resulting highly applicable DEM fulfils geometrical (numerical), geomorphological (shape), and semantic quality properties. Numéro de notice : A2012-513 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01332.x Date de publication en ligne : 10/10/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01332.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31959
in Transactions in GIS > vol 16 n° 5 (October 2012) . - pp 603 - 617[article]Digital terrain model resolution and its influence on estimating the extent of rockfall areas / T. Zieher in Transactions in GIS, vol 16 n° 5 (October 2012)
[article]
Titre : Digital terrain model resolution and its influence on estimating the extent of rockfall areas Type de document : Article/Communication Auteurs : T. Zieher, Auteur ; T. Formanek, Auteur ; Magnus Bremer, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 691 - 699 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] éboulement
[Termes IGN] modèle numérique de terrain
[Termes IGN] Python (langage de programmation)Résumé : (Auteur) As rockfall can cause a great deal of damage, it is essential to know its spatial propagation. Rockfall models are sensitive to the resolution of input data, i.e. the Digital Terrain Model (DTM) used. Nowadays, high resolution elevation data are available area-wide from airborne laser scanning (ALS). However, rockfall models are designed for analysis on a certain scale, which means that high resolution input might not necessarily improve model results (e.g. for regional scale studies). Our aim is to estimate the reach of rockfall by analysing different input resolutions of an ALS DTM. The presented empirically–based model, implemented in Python 2.7, is a modified version of the zenital method including an iterative random walk trajectory model, which is designed for rockfall hazard assessment at the regional scale. Trajectories and rockfall probability maps are generated for selected DTM input resolutions. The comparison shows that high resolution DTMs do consider local topography better and thus lead to more realistic results than low resolution DTMs. Numéro de notice : A2012-519 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01334.x Date de publication en ligne : 20/08/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01334.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31965
in Transactions in GIS > vol 16 n° 5 (October 2012) . - pp 691 - 699[article]High resolution DEM generation in high-alpine terrain using airborne remote sensing techniques / Y. Bühler in Transactions in GIS, vol 16 n° 5 (October 2012)
[article]
Titre : High resolution DEM generation in high-alpine terrain using airborne remote sensing techniques Type de document : Article/Communication Auteurs : Y. Bühler, Auteur ; M. Marty, Auteur ; C. Ginzler, Auteur Année de publication : 2012 Article en page(s) : pp 635 - 647 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] Alpes centrales
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] modèle numérique de surface
[Termes IGN] SuisseRésumé : (Auteur) Up-to-date and accurate digital elevation models (DEMs) are essential for many applications such as numerical modeling of mass movements or mapping of terrain changes. Today the Federal Department of Topography, swisstopo, provides Digital Terrain Models (DTMs) and Digital Surface Models (DSMs) derived from airborne LiDAR data with a high spatial resolution of 2 m covering the entire area of Switzerland below an elevation of 2000 m a.s.l.. However, above an elevation of 2000 m a.s.l., which is typical for high-alpine terrain, the best product available is the a DTM with a spatial resolution of 25 m. This spatial resolution is insufficient for many applications in complex terrain. In this study, we investigate the quality of DSMs derived from opto-electronic scanner data (ADS80; acquired in autumn 2010) using photogrammetric image correlation techniques based on the multispectral nadir and backward looking sensor data. As reference, we take a high precision airborne LiDAR data set with a spatial resolution of ca. 0.5 m, acquired in late summer 2010, covering the Grabengufer/Dorfbach catchment near Randa, VS. We find the deviations between the two datasets are surprisingly low. In terrain with inclination angles of less than 30° the RMSE is below 0.5 m. In extremely steep terrain of more than 50° the RMSE goes up to 2 m and outliers increase significantly. We also find dependencies of the deviations on illumination conditions and ground cover classes. Finally we discuss advantages and disadvantages of the different data acquisition methods. Numéro de notice : A2012-515 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01331.x Date de publication en ligne : 20/08/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01331.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31961
in Transactions in GIS > vol 16 n° 5 (October 2012) . - pp 635 - 647[article]Modelling flow routing in permafrost landscapes with TWI: an evaluation against site-specific wetness measurements / A. Persson in Transactions in GIS, vol 16 n° 5 (October 2012)
[article]
Titre : Modelling flow routing in permafrost landscapes with TWI: an evaluation against site-specific wetness measurements Type de document : Article/Communication Auteurs : A. Persson, Auteur ; A. Hasan, Auteur ; J. Tang, Auteur ; Petter Pilesjö, Auteur Année de publication : 2012 Article en page(s) : pp 701 - 713 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] changement climatique
[Termes IGN] dégel
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] humidité du sol
[Termes IGN] modèle numérique de surface
[Termes IGN] pergélisol
[Termes IGN] Suède
[Termes IGN] tourbeRésumé : (Auteur) In northern peatlands the thawing of permafrost increasing the active layer depth and changing the hydrology may lead to feedbacks in the climate system through changes in the biogeochemistry of carbon. We are examining this association on the Stordalen peatland complex in subarctic Sweden by analyzing a DEM derived from LiDAR-data and the calculated TWI [Topographical Wetness Index]. The DEM, with a spatial resolution of 1 m, and the TWI are evaluated against two seasons of water level measurements from 30 sites in the peatland. The TWI is calculated with a form-based flow routing algorithm which produces a natural flow routing pattern. In permafrost wetlands the topography is the major driver and is very important even though its magnitude is low. Site-specific wetness (SSW) measurements from the sites were compared with the different peatland types that occur in the study area, i.e. fen, internal fen and palsa. The results showed a strong correlation between the TWI and the palsa. The TWI was better at describing general patterns than site-specific hydrology. The evaluation of spatial patterns of TWI against SSW reveal the resolution required to develop the technique to be useful for climate change studies. Numéro de notice : A2012-520 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01338.x Date de publication en ligne : 22/08/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01338.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31966
in Transactions in GIS > vol 16 n° 5 (October 2012) . - pp 701 - 713[article]Lidar strip adjustment with automatically reconstructed roof shapes / M. Rentsch in Photogrammetric record, vol 27 n° 139 (September - November 2012)PermalinkA multi-resolution hybrid approach for building model reconstruction from lidar data / M. Satari in Photogrammetric record, vol 27 n° 139 (September - November 2012)PermalinkPermalinkPoint-to-plane registration of terrestrial laser scans / D. Grant in ISPRS Journal of photogrammetry and remote sensing, vol 72 (August 2012)PermalinkA robust signal preprocessing chain for small-footprint waveform LiDAR / J. Wu in IEEE Transactions on geoscience and remote sensing, vol 50 n° 8 (August 2012)PermalinkBuilding edge detection using small-footprint airborne full-waveform lidar data / Jean-Christophe Michelin in ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, vol I-3 (2012)PermalinkImproving 3D lidar point cloud registration using optimal neighborhood knowledge / Adrien Gressin in ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, vol I-3 (2012)PermalinkTrajectory-based registration of 3d lidar point clouds acquired with a mobile mapping system / Adrien Gressin in ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, vol I-3 (2012)PermalinkTrees detection from laser point clouds acquired in dense urban areas by a mobile mapping system / Fabrice Monnier in ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, vol I-3 (2012)Permalink3-D mapping of a multi-layered Mediterranean forest using ALS data / António Ferraz in Remote sensing of environment, vol 121 (June 2012)Permalink