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Termes IGN > 1-Candidats > semis de points
semis de points
Commentaire :
- Ensemble de points répartis de façon régulière ou quelconque sur une zone géographique donnée. (Glossaire de cartographie / CFC) Ces points peuvent être issus d'images ou de données lidar ...
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An average error-ellipsoid model for evaluating TLS point-cloud accuracy / Xijiang Chen in Photogrammetric record, vol 31 n° 153 (March - May 2016)
[article]
Titre : An average error-ellipsoid model for evaluating TLS point-cloud accuracy Type de document : Article/Communication Auteurs : Xijiang Chen, Auteur ; Guang Zhang, Auteur ; Xianghong Hua, Auteur ; Wei Xuan, Auteur Année de publication : 2016 Article en page(s) : pp 71 - 87 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] erreur moyenne
[Termes IGN] estimation statistique
[Termes IGN] précision des données
[Termes IGN] qualité des données
[Termes IGN] semis de points
[Termes IGN] télémétrie laser terrestreRésumé : (Auteur) Estimation of the accuracy of terrestrial laser scanning has become a topical research issue. Point-cloud accuracy should be clearly differentiated from the accuracy of individual points, as it is influenced by positional errors and adjacent error spaces. Furthermore, it cannot be determined by the sum of positional errors. In this paper, it is proposed that the average error-ellipsoid model is favourable for evaluating the accuracy of point clouds. Central to this model is the computation of the overlap between adjacent error ellipsoids and the determination of a functional relationship between the average volume of error ellipsoids and the point-cloud accuracy. This paper outlines the key advantages of the proposed evaluation model, such as the capability of providing an estimate of local point-cloud accuracy. The effectiveness of the model is discussed using a validation experiment. Numéro de notice : A2016-162 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/phor.12136 Date de publication en ligne : 02/03/2016 En ligne : https://doi.org/10.1111/phor.12136 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80462
in Photogrammetric record > vol 31 n° 153 (March - May 2016) . - pp 71 - 87[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 106-2016011 RAB Revue Centre de documentation En réserve L003 Disponible Assessing 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)
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Titre : Assessing the contribution of woody materials to forest angular gap fraction and effective leaf area index using terrestrial laser scanning data Type de document : Article/Communication Auteurs : Guang Zheng, Auteur ; Lixia Ma, Auteur ; Wei He, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 1475 - 1487 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] bois sur pied
[Termes IGN] classification automatique
[Termes IGN] distribution spatiale
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] indice foliaire
[Termes IGN] Leaf Area Index
[Termes IGN] photosynthèse
[Termes IGN] régression linéaire
[Termes IGN] semis de points
[Termes IGN] télémétrie laser terrestreRésumé : (Auteur) The spatial distribution of the photosynthetic components of a forest canopy plays a key role in ecological related processes such as gas exchange, photosynthesis, and evapotranspiration through affecting radiation regimes of the forest canopy. However, quantitative evaluation of woody materials' contribution to effective leaf area index (LAIe) using 3-D terrestrial laser scanning (TLS) is a challenging work. In this paper, we first identified the differences between directional gap fraction (DGF) and angular gap fraction (AGF) and then developed a local geometric feature-based approach to automatically classify a TLS forest point cloud data (PCD) into three different classes, including nonphotosynthetic canopy components (i.e., stem and branch points), photosynthetic canopy components (i.e., leaf and grass points), and bare ground. In addition, we proposed a new approach named “radial hemispherical point cloud slicing” algorithm to investigate the 3-D spatial distribution of foliage elements and retrieve LAIe from a given forest PCD. Our results showed that nonphotosynthetic canopy components contributed from 19% to 54% to LAIe depending on various forest densities. Moreover, TLS-based LAIe estimates can explain 74.27% variations of digital-hemispherical-photography-based LAIe values with a linear regression statistical model. This paper provides a theoretical foundation for LAI estimation based on the PCD generated using the TLS system and facilitates the application of TLS on retrieving 3-D forest canopy structural biophysical parameters. Numéro de notice : A2016-132 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2015.2481492 En ligne : http://dx.doi.org/10.1109/TGRS.2015.2481492 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80019
in IEEE Transactions on geoscience and remote sensing > vol 54 n° 3 (March 2016) . - pp 1475 - 1487[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2016031 SL Revue Centre de documentation Revues en salle Disponible Augmented 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)
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Titre : Augmented survey reality : a surveying firm in Western Australia is exploring the extents of the known Holoverse Type de document : Article/Communication Auteurs : Anthony Wallace, Auteur Année de publication : 2016 Article en page(s) : pp 18 - 20 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] données localisées 3D
[Termes IGN] immersion
[Termes IGN] réalité augmentée
[Termes IGN] semis de pointsRésumé : (auteur) [...] Stepping into the hologram room of Western Australian surveying firm WING Surveys, users don't just view 3D environments in a new way, they are given 'superpowers' and the ability to uncover otherwise unattainable insights. Equipped with tracked augmented reality glasses and immersed within a world supported by multiple 3D projectors, viewing experiences are no longer limited by physics or computing power, but only by human imagination. The hologram room, or `Holoverse as it is known by MNG is based on an Australian augmented reality technology for viewing 3D laser scanned data and high-density point cloud data. In stark contrast to the hype and disappointment of 3D movies and televisions, MNG believes the Holoverse is different. The Holoverse provides users in different industries with real value," said John Nolan of MNG. "It is envisaged that its uptake will be rapid once hardware becomes mass produced and appropriate content is available." Numéro de notice : A2016-235 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80710
in Position > n° 81 (February - March 2016) . - pp 18 - 20[article]Automatic detection and reconstruction of 2-D/3-D building shapes from spaceborne TomoSAR point clouds / Muhammad Shahzad in IEEE Transactions on geoscience and remote sensing, vol 54 n° 3 (March 2016)
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Titre : Automatic detection and reconstruction of 2-D/3-D building shapes from spaceborne TomoSAR point clouds Type de document : Article/Communication Auteurs : Muhammad Shahzad, Auteur ; Xiao Xiang Zhu, Auteur Année de publication : 2016 Article en page(s) : pp 1292 - 1310 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] angle de visée
[Termes IGN] Berlin
[Termes IGN] détection automatique
[Termes IGN] façade
[Termes IGN] image radar moirée
[Termes IGN] image TerraSAR-X
[Termes IGN] Las Vegas
[Termes IGN] reconstruction 2D du bâti
[Termes IGN] reconstruction 3D du bâti
[Termes IGN] semis de points
[Termes IGN] toit
[Termes IGN] tomographie radarRésumé : (Auteur) Modern spaceborne synthetic aperture radar (SAR) sensors, such as TerraSAR-X/TanDEM-X and COSMO-SkyMed, can deliver very high resolution (VHR) data beyond the inherent spatial scales of buildings. Processing these VHR data with advanced interferometric techniques, such as SAR tomography (TomoSAR), allows for the generation of four-dimensional point clouds, containing not only the 3-D positions of the scatterer location but also the estimates of seasonal/temporal deformation on the scale of centimeters or even millimeters, making them very attractive for generating dynamic city models from space. Motivated by these chances, the authors have earlier proposed approaches that demonstrated first attempts toward reconstruction of building facades from this class of data. The approaches work well when high density of facade points exists, and the full shape of the building could be reconstructed if data are available from multiple views, e.g., from both ascending and descending orbits. However, there are cases when no or only few facade points are available. This usually happens for lower height buildings and renders the detection of facade points/regions very challenging. Moreover, problems related to the visibility of facades mainly facing toward the azimuth direction (i.e., facades orthogonally oriented to the flight direction) can also cause difficulties in deriving the complete structure of individual buildings. These problems motivated us to reconstruct full 2-D/3-D shapes of buildings via exploitation of roof points. In this paper, we present a novel and complete data-driven framework for the automatic (parametric) reconstruction of 2-D/3-D building shapes (or footprints) using unstructured TomoSAR point clouds particularly generated from one viewing angle only. The proposed approach is illustrated and validated by examples using TomoSAR point clouds generated using TerraSAR-X high-resolution spotlight data stacks acquired from ascending orbit covering two differen- test areas, with one containing simple moderate-sized buildings in Las Vegas, USA and the other containing relatively complex building structures in Berlin, Germany. Numéro de notice : A2016-129 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2015.2477429 En ligne : http://dx.doi.org/10.1109/TGRS.2015.2477429 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80016
in IEEE Transactions on geoscience and remote sensing > vol 54 n° 3 (March 2016) . - pp 1292 - 1310[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2016031 SL Revue Centre de documentation Revues en salle Disponible Correction of terrestrial LiDAR intensity channel using Oren–Nayar reflectance model: An application to lithological differentiation / Dario Carrea in ISPRS Journal of photogrammetry and remote sensing, vol 113 (March 2016)
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Titre : Correction of terrestrial LiDAR intensity channel using Oren–Nayar reflectance model: An application to lithological differentiation Type de document : Article/Communication Auteurs : Dario Carrea, Auteur ; Antonio Abellan, Auteur ; Florian Humair, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 17 - 29 Note générale : bibliothèque Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] angle d'incidence
[Termes IGN] correction d'image
[Termes IGN] distance euclidienne
[Termes IGN] données lidar
[Termes IGN] réflectance du sol
[Termes IGN] semis de points
[Termes IGN] télémétrie laser terrestre
[Termes IGN] test de performanceRésumé : (auteur) Ground-based LiDAR has been traditionally used for surveying purposes via 3D point clouds. In addition to XYZ coordinates, an intensity value is also recorded by LiDAR devices. The intensity of the backscattered signal can be a significant source of information for various applications in geosciences.
Previous attempts to account for the scattering of the laser signal are usually modelled using a perfect diffuse reflection. Nevertheless, experience on natural outcrops shows that rock surfaces do not behave as perfect diffuse reflectors. The geometry (or relief) of the scanned surfaces plays a major role in the recorded intensity values.
Our study proposes a new terrestrial LiDAR intensity correction, which takes into consideration the range, the incidence angle and the geometry of the scanned surfaces. The proposed correction equation combines the classical radar equation for LiDAR with the bidirectional reflectance distribution function of the Oren–Nayar model. It is based on the idea that the surface geometry can be modelled by a relief of multiple micro-facets. This model is constrained by only one tuning parameter: the standard deviation of the slope angle distribution (σslope) of micro-facets.
Firstly, a series of tests have been carried out in laboratory conditions on a 2 m2 board covered by black/white matte paper (perfect diffuse reflector) and scanned at different ranges and incidence angles. Secondly, other tests were carried out on rock blocks of different lithologies and surface conditions. Those tests demonstrated that the non-perfect diffuse reflectance of rock surfaces can be practically handled by the proposed correction method.
Finally, the intensity correction method was applied to a real case study, with two scans of the carbonate rock outcrop of the Dents-du-Midi (Swiss Alps), to improve the lithological identification for geological mapping purposes. After correction, the intensity values are proportional to the intrinsic material reflectance and are independent from range, incidence angle and scanned surface geometry. The corrected intensity values significantly improve the material differentiation.Numéro de notice : A2016-532 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2015.12.004 En ligne : https://doi.org/10.1016/j.isprsjprs.2015.12.004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81616
in ISPRS Journal of photogrammetry and remote sensing > vol 113 (March 2016) . - pp 17 - 29[article]Laser 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)PermalinkOctree-based segmentation for terrestrial LiDAR point cloud data in industrial applications / Yun-Ting Su in ISPRS Journal of photogrammetry and remote sensing, vol 113 (March 2016)PermalinkRobust spatial approximation of laser scanner point clouds by means of Free-form Curve approaches in deformation analysis / Johannes Bureick in Journal of applied geodesy, vol 10 n° 1 (March 2016)PermalinkImproved salient feature-based approach for automatically separating photosynthetic and nonphotosynthetic components within terrestrial Lidar point cloud data of forest canopies / Lixia Ma in IEEE Transactions on geoscience and remote sensing, vol 54 n° 2 (February 2016)PermalinkLarge-scale road detection in forested mountainous areas using airborne topographic lidar data / António Ferraz in ISPRS Journal of photogrammetry and remote sensing, vol 112 (February 2016)PermalinkObject classification and recognition from mobile laser scanning point clouds in a road environment / Matti Lehtomäki in IEEE Transactions on geoscience and remote sensing, vol 54 n° 2 (February 2016)PermalinkReconstructing a church in 3D / Matthias Naumann in GIM international [en ligne], vol 30 n° 2 (February 2016)PermalinkA wavelet-based echo detector for waveform LiDAR data / Cheng-Kai Wang in IEEE Transactions on geoscience and remote sensing, vol 54 n° 2 (February 2016)PermalinkPermalinkAcquisition et reconstruction de données 3D denses sous-marines en eau peu profonde par des robots d'exploration / Loïca Avanthey (2016)Permalink