Descripteur
Documents disponibles dans cette catégorie (1139)
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
Laser scanning in engineering surveying : methods of measurement and modeling of structures / Grzegorz Lenda in Reports on geodesy and geoinformatics, vol 100 (May 2016)
[article]
Titre : Laser scanning in engineering surveying : methods of measurement and modeling of structures Type de document : Article/Communication Auteurs : Grzegorz Lenda, Auteur ; Andrzej Uznański, Auteur ; Michal Strach, Auteur ; Paulina Lewińska, Auteur Année de publication : 2016 Article en page(s) : pp 109 - 130 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] semis de points
[Termes IGN] télémétrie laser aéroporté
[Termes IGN] télémétrie laser mobile
[Termes IGN] télémétrie laser terrestreRésumé : (Auteur) The study is devoted to the uses of laser scanning in the field of engineering surveying. It is currently one of the main trends of research which is developed at the Department of Engineering Surveying and Civil Engineering at the Faculty of Mining Surveying and Environmental Engineering of AGH University of Science and Technology in Krakow. They mainly relate to the issues associated with tower and shell structures, infrastructure of rail routes, or development of digital elevation models for a wide range of applications. These issues often require the use of a variety of scanning techniques (stationary, mobile), but the differences also regard the planning of measurement stations and methods of merging point clouds. Significant differences appear during the analysis of point clouds, especially when modeling objects. Analysis of the selected parameters is already possible basing on ad hoc measurements carried out on a point cloud. However, only the construction of three-dimensional models provides complete information about the shape of structures, allows to perform the analysis in any place and reduces the amount of the stored data. Some structures can be modeled in the form of simple axes, sections, or solids, for others it becomes necessary to create sophisticated models of surfaces, depicting local deformations. The examples selected for the study allow to assess the scope of measurement and office work for a variety of uses related to the issue set forth in the title of this study. Additionally, the latest, forward-looking technology was presented - laser scanning performed from Unmanned Aerial Vehicles (drones). Currently, it is basically in the prototype phase, but it might be expected to make a significant progress in numerous applications in the field of engineering surveying. Numéro de notice : A2016-648 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1515/rgg-2016-0010 En ligne : http://dx.doi.org/10.1515/rgg-2016-0010 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81854
in Reports on geodesy and geoinformatics > vol 100 (May 2016) . - pp 109 - 130[article]Multisensor and multispectral Lidar characterization and classification of a forest environment / Christopher Hopkinson in Canadian journal of remote sensing, vol 42 n° 5 ([01/05/2016])
[article]
Titre : Multisensor and multispectral Lidar characterization and classification of a forest environment Type de document : Article/Communication Auteurs : Christopher Hopkinson, Auteur ; Laura Chasmer, Auteur ; Chris Gynan, Auteur ; Craig Mahoney, Auteur ; Michael Sitar, Auteur Année de publication : 2016 Article en page(s) : pp 501 - 520 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] canopée
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] erreur systématique
[Termes IGN] feuille (végétation)
[Termes IGN] modèle numérique de surface
[Termes IGN] modèle numérique de surface de la canopée
[Termes IGN] rayonnement proche infrarougeRésumé : (auteur) Airborne LiDAR is increasingly used in forest carbon, ecosystem, and resource monitoring. For practical design and manufacture reasons, the 1064 nm near-infrared (NIR) wavelength has been the most commonly adopted, and most literature in this field represents sampling characteristics in this wavelength. However, due to eye-safety and application-specific needs, other common wavelengths are 1550 nm and 532 nm. All provide canopy structure reconstructions that can be integrated or compared through space and time but the consistency or complementarity of 3D airborne LiDAR data sampled at multiple wavelengths is poorly understood. Here, we report on multispectral LiDAR missions carried out in 2013 and 2015 over a managed forest research site. The 1st used 3 independent sensors, and the 2nd used a single sensor carrying 3 lasers. The experiment revealed differences in proportions of returns at ground level, vertical foliage distributions, and gap probability across wavelengths. Canopy attenuation was greatest at 532 nm, presumably due to leaf tissue absorption. Relative to 1064 nm, foliage was undersampled at midheight percentiles at 1550 nm and 532 nm. Multisensor data demonstrated differences in foliage characterization due to combined influences of wavelength and acquisition configuration. Single-sensor multispectral data were more stable but demonstrated clear wavelength-dependent variation that could be exploited in intensity-based land cover classification without the aid of 3D derivatives. This work sets the stage for improvements in land surface classification and vertical foliage partitioning through the integration of active spectral and structural laser return information. Numéro de notice : A2016--128 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.1080/07038992.2016.1196584 En ligne : http://dx.doi.org/10.1080/07038992.2016.1196584 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85114
in Canadian journal of remote sensing > vol 42 n° 5 [01/05/2016] . - pp 501 - 520[article]Robust approximation of the Medial Axis Transform of LiDAR point clouds as a tool for visualisation / Ravi Peters in Computers & geosciences, vol 90 part A (May 2016)
[article]
Titre : Robust approximation of the Medial Axis Transform of LiDAR point clouds as a tool for visualisation Type de document : Article/Communication Auteurs : Ravi Peters, Auteur ; Hugo Ledoux, Auteur Année de publication : 2016 Article en page(s) : pp 123 - 133 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] axe médian
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] géovisualisation
[Termes IGN] semis de points
[Termes IGN] simplification de surface
[Termes IGN] transformation géométrique
[Termes IGN] visualisation 3DRésumé : (auteur) Governments and companies around the world collect point clouds (datasets containing elevation points) because these are useful for many applications, e.g. to reconstruct 3D city models, to understand and predict the impact of floods, and to monitor dikes. We address in this paper the visualisation of point clouds, which is perhaps the most essential instrument a practitioner or a scientist has to analyse and understand such datasets. We argue that it is currently hampered by two main problems: (1) point clouds are often massive (several billion points); (2) the viewer's perception of depth and structure is often lost (because of the sparse and unstructured points). We propose solving both problems by using the Medial Axis Transform (MAT) and its properties. This allows us to (1) smartly simplify a point cloud in a geometry-dependent way (to preserve only significant features), and (2) to render splats whose radii are adaptive to the distribution of points (and thus obtain less “holes” in the surface). Our main contribution is a series of heuristics that allows us to compute the MAT robustly for noisy real-world LiDAR point clouds, and to compute the MAT for point clouds that do not fit into the main memory. We have implemented our algorithms, we report on experiments made with point clouds (of more than one billion points), and we demonstrate that we are able to render scenes with much less points than in the original point cloud (we preserve around 10%) while retaining good depth-perception and a sense of structure at close viewing distances. Numéro de notice : A2016--063 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.cageo.2016.02.019 En ligne : http://dx.doi.org/10.1016/j.cageo.2016.02.019 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84237
in Computers & geosciences > vol 90 part A (May 2016) . - pp 123 - 133[article]Terrestrial laser scanning in forest inventories / Xinlian Liang in ISPRS Journal of photogrammetry and remote sensing, vol 115 (May 2016)
[article]
Titre : Terrestrial laser scanning in forest inventories Type de document : Article/Communication Auteurs : Xinlian Liang, Auteur ; Ville Kankare, Auteur ; Juha Hyyppä, Auteur Année de publication : 2016 Article en page(s) : pp 63 – 77 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] forêt
[Termes IGN] inventaire forestier (techniques et méthodes)
[Termes IGN] semis de points
[Termes IGN] télémétrie laser terrestreRésumé : (auteur) Decision making on forest resources relies on the precise information that is collected using inventory. There are many different kinds of forest inventory techniques that can be applied depending on the goal, scale, resources and the required accuracy. Most of the forest inventories are based on field sample. Therefore, the accuracy of the forest inventories depends on the quality and quantity of the field sample. Conventionally, field sample has been measured using simple tools. When map is required, remote sensing materials are needed. Terrestrial laser scanning (TLS) provides a measurement technique that can acquire millimeter-level of detail from the surrounding area, which allows rapid, automatic and periodical estimates of many important forest inventory attributes. It is expected that TLS will be operationally used in forest inventories as soon as the appropriate software becomes available, best practices become known and general knowledge of these findings becomes more wide spread. Meanwhile, mobile laser scanning, personal laser scanning, and image-based point clouds became capable of capturing similar terrestrial point cloud data as TLS. This paper reviews the advances of applying TLS in forest inventories, discusses its properties with reference to other related techniques and discusses the future prospects of this technique. Numéro de notice : A2016-545 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2016.01.006 En ligne : http://dx.doi.org/10.1016/j.isprsjprs.2016.01.006 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81691
in ISPRS Journal of photogrammetry and remote sensing > vol 115 (May 2016) . - pp 63 – 77[article]Capturing reality in 2016 / Daniel Chapek in xyHt, vol 2016 n° 4 (April 2016)
[article]
Titre : Capturing reality in 2016 Type de document : Article/Communication Auteurs : Daniel Chapek, Auteur Année de publication : 2016 Article en page(s) : pp 42 - 43 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] données localisées 3D
[Termes IGN] modélisation 3D du bâti BIMRésumé : (auteur) [introduction] Ten years on, 3D and BIM are the de facto standards for design. It took firms a long time to recognize the efficiencies of moving away from unintelligent 2D, and we're now seeing a similar pattern in the digital reality capture industry. Among building and manufacturing professionals, reality capture is of growing interest, but it is taking time for firms to understand its power and to alter their workflows to justify the investment in software and equipment. Because reality capture can significantly reduce time to model as well as increase model accuracy, 2016 is poised to be a breakout year. Numéro de notice : A2016-616 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/IMAGERIE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81817
in xyHt > vol 2016 n° 4 (April 2016) . - pp 42 - 43[article]Project pointless : pathfinding through identified empty space in point clouds / Tom Broersen in GIM international, vol 30 n° 4 (April 2016)PermalinkStreet-side vehicle detection, classification and change detection using mobile laser scanning data / Wen Xiao in ISPRS Journal of photogrammetry and remote sensing, vol 114 (April 2016)PermalinkOn the interest of penetration depth, canopy area and volume metrics to improve Lidar-based models of forest parameters / Cédric Vega in Remote sensing of environment, vol 175 (15 March 2016)PermalinkAn average error-ellipsoid model for evaluating TLS point-cloud accuracy / Xijiang Chen in Photogrammetric record, vol 31 n° 153 (March - May 2016)PermalinkAssessing the contribution of woody materials to forest angular gap fraction and effective leaf area index using terrestrial laser scanning data / Guang Zheng in IEEE Transactions on geoscience and remote sensing, vol 54 n° 3 (March 2016)PermalinkAugmented survey reality : a surveying firm in Western Australia is exploring the extents of the known Holoverse / Anthony Wallace in Position, n° 81 (February - March 2016)PermalinkChallenges and present fields of action at laser scanner based deformation analyses / Christoph Holst in Journal of applied geodesy, vol 10 n° 1 (March 2016)PermalinkDie Fortführung des 3D-Gebäudemodells LoD2 in Nordrhein-Westfalen / Marco Oestereich in ZFV, Zeitschrift für Geodäsie, Geoinformation und Landmanagement, Vol 141 n° 3 (Mai - Juni 2016)PermalinkDocumentation et gestion d'un site archéologique : cas de Masseria Cesareo / D. Constantino in Géomatique expert, n° 109 (mars - avril 2016)PermalinkLaser scanning based growth analysis of plants as a new challenge for deformation monitoring / Jan Dupuis in Journal of applied geodesy, vol 10 n° 1 (March 2016)Permalink