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Weighted simplicial complex reconstruction from mobile laser scanning using sensor topology / Stéphane Guinard in Revue Française de Photogrammétrie et de Télédétection, n° 217-218 (juin - septembre 2018)  

Public [article]  inRevue Française de Photogrammétrie et de Télédétection > n° 217-218 (juin - septembre 2018) . - pp 63 - 71 Titre : Weighted simplicial complex reconstruction from mobile laser scanning using sensor topology Type de document : Article/Communication Auteurs : Stéphane Guinard , Auteur ; Bruno Vallet , Auteur Année de publication : 2018 Projets : 1-Pas de projet / Article en page(s) : pp 63 - 71 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] complexe simplicial [Termes IGN] coplanarité [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] modèle géométrique [Termes IGN] pondération [Termes IGN] reconstruction 3D [Termes IGN] relation topologique [Termes IGN] relation topologique 3D [Termes IGN] semis de points Résumé : (auteur) Nous présentons une nouvelle méthode pour la reconstruction de complexes simpliciaux (ensembles de points, segments et triangles) à partir de nuages de points 3D obtenus par LiDAR mobile, à balayage plan. Notre méthode utilise la topologie inhérente au capteur LiDAR pour définir une relation spatiale entre les points. Pour cela, nous examinons chaque connexion possible entre points, pondérée en fonction de sa distance au capteur, et les filtrons en privilégiant les structures collinéaires, ou perpendiculaires aux impulsions du laser. Ensuite, nous créons et filtrons des triangles pour chaque triplet de segments connectés entre eux, en fonction de leur coplanarité locale. Nous comparons nos résultats à une reconstruction non pondérée d'un complexe simplicial. Numéro de notice : A2018-497 Affiliation des auteurs : LASTIG MATIS (2012-2019) Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueNat DOI : 10.52638/rfpt.2018.412 En ligne : https://doi.org/10.52638/rfpt.2018.412 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91263 [article]

Development of a Protocol to Convert and Manage Underground Infrastructure Maps into Geographic Information Systems (GIS) Format / Guillemette Fonteix (2018) 

Public Titre : Development of a Protocol to Convert and Manage Underground Infrastructure Maps into Geographic Information Systems (GIS) Format Type de document : Mémoire Auteurs : Guillemette Fonteix, Auteur Editeur : Champs-sur-Marne : Ecole nationale des sciences géographiques ENSG Année de publication : 2018 Importance : 32 p. Format : 21 x 30 cm Note générale : bibliographie Rapport de projet pluridisciplinaire, cycle Ingénieur 2e année Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] apprentissage automatique [Termes IGN] ArcGIS [Termes IGN] base de données localisées [Termes IGN] conception assistée par ordinateur [Termes IGN] conversion de données [Termes IGN] correction géométrique [Termes IGN] dessin assisté par ordinateur [Termes IGN] FME [Termes IGN] géocodage [Termes IGN] gestion urbaine [Termes IGN] protocole [Termes IGN] Python (langage de programmation) [Termes IGN] relation topologique 3D [Termes IGN] réseau technique souterrain [Termes IGN] réseau technique urbain [Termes IGN] système d'information urbain Index. décimale : PROJET Mémoires : Rapports de projet - stage des ingénieurs de 2e année Résumé : (auteur) In the cities, the underground networks system become more and more dense because of the occupation of many infrastructures for water, storm-water, sewer, electricity, gas, etc. Urban and ecological problems can be faced thanks to them. However, they are difficult to manage because of the impossibility of seeing them. The location of existing infrastructures is a necessity for controlling their development. Converting from CAD to GIS may improve the CAD drawings with spatial information and attributes and allows a better accessibility, accuracy and performance [Warner, 2013]. The Geographic Information System (GIS) implementation process for municipalities can be very complex, expensive, and time consuming, depending on the knowledge of municipalities. Maps of underground infrastructure systems are mainly stored in paper or CAD format and many cities and organizations around the world are putting significant efforts into converting those maps into GIS format. However, most of these efforts are uncoordinated and a formal protocol is missing to deal with GIS map update and version control. During this internship, it was asked to survey current practices in the world and develop a formal protocol to convert and manage GIS maps of underground infrastructure systems. The project required a technical expertise (to account for the potentials and limits of GIS) and specific knowledge about underground infrastructure systems. I had to survey current efforts in the world to convert and manage underground maps mainly thanks to a survey of municipalities and through online searches. Then developed a formal protocol illustrated by a general flowchart that should offer a streamlined strategy to ensure effective conversion from CAD to GIS and allows a better data management. The project resulted in a scientific publication. These works allowed me to develop GIS, Python, communication and writing skills in English. Note de contenu : Introduction 1- Challenges faced 2- Data management 3- Work carried out Conclusion Numéro de notice : 21810 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Mémoire de projet pluridisciplinaire Organisme de stage : Complex and Sustainable Urban Networks laboratory Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91298

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
21810-01	PROJET	Livre	Centre de documentation	Travaux d'élèves	Disponible

Documents numériques

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Object-based classification of terrestrial laser scanning point clouds for landslide monitoring / Andreas Mayr in Photogrammetric record, vol 32 n° 160 (December 2017)  

Public [article]  inPhotogrammetric record > vol 32 n° 160 (December 2017) . - pp 377 - 397 Titre : Object-based classification of terrestrial laser scanning point clouds for landslide monitoring Type de document : Article/Communication Auteurs : Andreas Mayr, Auteur ; Martin Rutzinger, Auteur ; Magnus Bremer, Auteur ; Sander J. Oude Elberink, Auteur ; Felix Stumpf, Auteur ; Clemens Geitner, Auteur Année de publication : 2017 Conférence : VGC 2016, 2nd virtual geoscience conference 22/09/2016 23/09/2016 Bergen Norvège Proceedings Wiley Article en page(s) : pp 377 - 397 Note générale : bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] apprentissage automatique [Termes IGN] classification orientée objet [Termes IGN] compréhension de l'image [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] effondrement de terrain [Termes IGN] relation topologique 3D [Termes IGN] semis de points [Termes IGN] surveillance géologique Résumé : (auteur) Terrestrial laser scanning (TLS) is often used to monitor landslides and other gravitational mass movements with high levels of geometric detail and accuracy. However, unstructured TLS point clouds lack semantic information, which is required to geomorphologically interpret the measured changes. Extracting meaningful objects in a complex and dynamic environment is challenging due to the objects' fuzziness in reality, as well as the variability and ambiguity of their patterns in a morphometric feature space. This work presents a point‐cloud‐based approach for classifying multitemporal scenes of a hillslope affected by shallow landslides. The 3D point clouds are segmented into morphologically homogeneous and spatially connected parts. These segments are classified into seven target classes (scarp, eroded area, deposit, rock outcrop and different classes of vegetation) in a two‐step procedure: a supervised classification step with a machine‐learning classifier using morphometric features, followed by a correction step based on topological rules. This improves the final object extraction considerably. Numéro de notice : A2017-899 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/phor.12215 Date de publication en ligne : 13/12/2017 En ligne : https://doi.org/10.1111/phor.12215 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89522 [article]

Reconstructing forest canopy from the 3D triangulations of airborne laser scanning point data for the visualization and planning of forested landscapes / Jari Vauhkonen in Annals of Forest Science, vol 74 n° 1 (March 2017)  

Public [article]  inAnnals of Forest Science > vol 74 n° 1 (March 2017) Titre : Reconstructing forest canopy from the 3D triangulations of airborne laser scanning point data for the visualization and planning of forested landscapes Type de document : Article/Communication Auteurs : Jari Vauhkonen, Auteur ; Roope Ruotsalainen, Auteur Année de publication : 2017 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] analyse multicritère [Termes IGN] biomasse forestière [Termes IGN] canopée [Termes IGN] coupe (sylviculture) [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] géovisualisation [Termes IGN] modèle de simulation [Termes IGN] participation du public [Termes IGN] processus de hiérarchisation analytique [Termes IGN] reconstruction 3D [Termes IGN] relation topologique 3D [Termes IGN] SIG participatif [Termes IGN] simulation numérique [Termes IGN] tronc Résumé : (Auteur) We present a data-driven technique to visualize forest landscapes and simulate their future development according to alternative management scenarios. Gentle harvesting intensities were preferred for maintaining scenic values in a test of eliciting public’s preferences based on the simulated landscapes. Context : Visualizations of future forest landscapes according to alternative management scenarios are useful for eliciting stakeholders’ preferences on the alternatives. However, conventional computer visualizations require laborious tree-wise measurements or simulators to generate these observations. Aims : We describe and evaluate an alternative approach, in which the visualization is based on reconstructing forest canopy from sparse density, leaf-off airborne laser scanning data. Methods : Computational geometry was employed to generate filtrations, i.e., ordered sets of simplices belonging to the three-dimensional triangulations of the point data. An appropriate degree of filtering was determined by analyzing the topological persistence of the filtrations. The topology was further utilized to simulate changes to canopy biomass, resembling harvests with varying retention levels. Relative priorities of recreational and scenic values of the harvests were estimated based on pairwise comparisons and analytic hierarchy process (AHP). Results : The canopy elements were co-located with the tree stems measured in the field, and the visualizations derived from the entire landscape showed reasonably realistic, despite a low numerical correspondence with plot-level forest attributes. The potential and limitations to improve the proposed parameterization are discussed. Conclusion : Although the criteria to evaluate the landscape visualization and simulation models were not conclusive, the results suggest that forest scenes may be feasibly reconstructed based on data already covering broad areas and readily available for practical applications. Numéro de notice : A2017-041 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.1007/s13595-016-0598-6 Date de publication en ligne : 06/07/2017 En ligne : http://doi.org/10.1007/s13595-016-0598-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84199 [article]

A two-level topological model for 3D features in CityGML / Lin Li in Computers, Environment and Urban Systems, vol 59 (September 2016)  

Public [article]  inComputers, Environment and Urban Systems > vol 59 (September 2016) . - pp 11- 24 Titre : A two-level topological model for 3D features in CityGML Type de document : Article/Communication Auteurs : Lin Li, Auteur ; Feng Luo, Auteur ; Haihong Zhu, Auteur ; Shen Ying, Auteur ; Zhigang Zhao, Auteur Année de publication : 2016 Article en page(s) : pp 11- 24 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications SIG [Termes IGN] CityGML [Termes IGN] contrainte de cohérence [Termes IGN] intégrité topologique [Termes IGN] modèle 3D de l'espace urbain [Termes IGN] modèle topologique de données [Termes IGN] niveau de détail [Termes IGN] objet géographique 3D [Termes IGN] primitive géométrique [Termes IGN] relation topologique [Termes IGN] relation topologique 3D [Termes IGN] SIG 3D Résumé : (auteur) CityGML, as the standard for the representation and exchange of 3D city models, contains rich information in terms of geometry, semantics, topology and appearance. With respect to topology, CityGML adopts the XLink approach to represent topological relationships between different geometric aggregates or thematic features; however, it is limited to shared objects. This paper proposes a two-level model for representing 3D topological relationships in CityGML: high-level (semantic-level) topology between semantic features and low-level (geometric-level) topology between geometric primitives. Five topological relationships are adopted in this model: touch, in, equal, overlap and disjoint. The semantic-level topology is derived from the geometric-level topology on the basis of the shared geometric primitives. To maintain the 3D topology, topological consistency rules are presented. An Application Domain Extension, called TopoADE, is proposed for the implementation of the topological model. The TopoADE consists of three modules: Topology, Feature and Geometry. Finally, 3D city models with LoD1 to LoD4 are used to test this model. Experimentation on those data sets indicates a validation of the proposed topological model in CityGML. Numéro de notice : A2016-405 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.compenvurbsys.2016.04.007 Date de publication en ligne : 12/05/2016 En ligne : http://dx.doi.org/10.1016/j.compenvurbsys.2016.04.007 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81228 [article]