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Extracting spatial patterns in bicycle routes from crowdsourced data / Jody Sultan in Transactions in GIS, vol 21 n° 6 (December 2017)
[article]
Titre : Extracting spatial patterns in bicycle routes from crowdsourced data Type de document : Article/Communication Auteurs : Jody Sultan, Auteur ; Gev Ben‐Haim, Auteur ; Jan‐Henrik Haunert, Auteur ; Sagi Dalyot, Auteur Année de publication : 2017 Article en page(s) : pp 1321 - 1340 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] Amsterdam (Pays-Bas)
[Termes IGN] cycliste
[Termes IGN] données localisées des bénévoles
[Termes IGN] extraction de modèle
[Termes IGN] trace GPS
[Termes IGN] trajet (mobilité)Résumé : (auteur) Much is done nowadays to provide cyclists with safe and sustainable road infrastructure. Its development requires the investigation of road usage and interactions between traffic commuters. This article is focused on exploiting crowdsourced user‐generated data, namely GPS trajectories collected by cyclists and road network infrastructure generated by citizens, to extract and analyze spatial patterns and road‐type use of cyclists in urban environments. Since user‐generated data shows data‐deficiencies, we introduce tailored spatial data‐handling processes for which several algorithms are developed and implemented. These include data filtering and segmentation, map‐matching and spatial arrangement of GPS trajectories with the road network. A spatial analysis and a characterization of road‐type use are then carried out to investigate and identify specific spatial patterns of cycle routes. The proposed analysis was applied to the cities of Amsterdam (The Netherlands) and Osnabrück (Germany), proving its feasibility and reliability in mining road‐type use and extracting pattern information and preferences. This information can help users who wish to explore friendlier and more interesting cycle patterns, based on collective usage, as well as city planners and transportation experts wishing to pinpoint areas most in need of further development and planning. Numéro de notice : A2017-838 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/tgis.12280 Date de publication en ligne : 06/06/2017 En ligne : https://doi.org/10.1111/tgis.12280 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89374
in Transactions in GIS > vol 21 n° 6 (December 2017) . - pp 1321 - 1340[article]A classification-segmentation framework for the detection of individual trees in dense MMS point cloud data acquired in urban areas / Martin Weinmann in Remote sensing, vol 9 n° 3 (March 2017)
[article]
Titre : A classification-segmentation framework for the detection of individual trees in dense MMS point cloud data acquired in urban areas Type de document : Article/Communication Auteurs : Martin Weinmann, Auteur ; Michael Weinmann, Auteur ; Clément Mallet , Auteur ; Mathieu Brédif , Auteur Année de publication : 2017 Projets : IQmulus / Métral, Claudine Article en page(s) : pp 277 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] algorithme de décalage moyen
[Termes IGN] arbre (flore)
[Termes IGN] classification
[Termes IGN] Delft (Pays-Bas)
[Termes IGN] détection d'objet
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] segmentation
[Termes IGN] semis de points
[Termes IGN] voxel
[Termes IGN] zone urbaineRésumé : (auteur) In this paper, we present a novel framework for detecting individual trees in densely sampled 3D point cloud data acquired in urban areas. Given a 3D point cloud, the objective is to assign point-wise labels that are both class-aware and instance-aware, a task that is known as instance-level segmentation. To achieve this, our framework addresses two successive steps. The first step of our framework is given by the use of geometric features for a binary point-wise semantic classification with the objective of assigning semantic class labels to irregularly distributed 3D points, whereby the labels are defined as “tree points” and “other points”. The second step of our framework is given by a semantic segmentation with the objective of separating individual trees within the “tree points”. This is achieved by applying an efficient adaptation of the mean shift algorithm and a subsequent segment-based shape analysis relying on semantic rules to only retain plausible tree segments. We demonstrate the performance of our framework on a publicly available benchmark dataset, which has been acquired with a mobile mapping system in the city of Delft in the Netherlands. This dataset contains 10.13 M labeled 3D points among which 17.6 % are labeled as “tree points”. The derived results clearly reveal a semantic classification of high accuracy (up to 90.77 %) and an instance-level segmentation of high plausibility, while the simplicity, applicability and efficiency of the involved methods even allow applying the complete framework on a standard laptop computer with a reasonable processing time (less than 2.5 h) Numéro de notice : A2017-140 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/rs9030277 Date de publication en ligne : 16/03/2017 En ligne : http://doi.org/10.3390/rs9030277 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84614
in Remote sensing > vol 9 n° 3 (March 2017) . - pp 277[article]Agricultural cropland mapping using black-and-white aerial photography, Object-Based Image Analysis and Random Forests / M.F.A. Vogels in International journal of applied Earth observation and geoinformation, vol 54 (February 2017)
[article]
Titre : Agricultural cropland mapping using black-and-white aerial photography, Object-Based Image Analysis and Random Forests Type de document : Article/Communication Auteurs : M.F.A. Vogels, Auteur ; S.M. de Jong, Auteur ; G. Sterk, Auteur ; E.A. Addink, Auteur Année de publication : 2017 Article en page(s) : pp 114 - 123 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse d'image orientée objet
[Termes IGN] base de données historiques
[Termes IGN] carte agricole
[Termes IGN] classification par forêts d'arbres décisionnels
[Termes IGN] cultures
[Termes IGN] Ethiopie
[Termes IGN] image numérisée
[Termes IGN] Pays-Bas
[Termes IGN] photographie aérienne
[Termes IGN] photographie en noir et blanc
[Termes IGN] surface cultivée
[Termes IGN] utilisation du solRésumé : (auteur) Land-use and land-cover (LULC) conversions have an important impact on land degradation, erosion and water availability. Information on historical land cover (change) is crucial for studying and modelling land- and ecosystem degradation. During the past decades major LULC conversions occurred in Africa, Southeast Asia and South America as a consequence of a growing population and economy. Most distinct is the conversion of natural vegetation into cropland. Historical LULC information can be derived from satellite imagery, but these only date back until approximately 1972. Before the emergence of satellite imagery, landscapes were monitored by black-and-white (B&W) aerial photography. This photography is often visually interpreted, which is a very time-consuming approach. This study presents an innovative, semi-automated method to map cropland acreage from B&W photography. Cropland acreage was mapped on two study sites in Ethiopia and in The Netherlands. For this purpose we used Geographic Object-Based Image Analysis (GEOBIA) and a Random Forest classification on a set of variables comprising texture, shape, slope, neighbour and spectral information. Overall mapping accuracies attained are 90% and 96% for the two study areas respectively. This mapping method increases the timeline at which historical cropland expansion can be mapped purely from brightness information in B&W photography up to the 1930s, which is beneficial for regions where historical land-use statistics are mostly absent. Numéro de notice : A2017-050 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.jag.2016.09.003 En ligne : http://dx.doi.org/10.1016/j.jag.2016.09.003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84229
in International journal of applied Earth observation and geoinformation > vol 54 (February 2017) . - pp 114 - 123[article]Crossing boundaries: mapping spatial dynamics of urban phenomena at micro scale to support urban management in the Amsterdam urban region / Els Veldhuizen in Belgeo, vol 2016 n° 2 (2016-2)
[article]
Titre : Crossing boundaries: mapping spatial dynamics of urban phenomena at micro scale to support urban management in the Amsterdam urban region Type de document : Article/Communication Auteurs : Els Veldhuizen, Auteur ; Karin Pfeffer, Auteur Année de publication : 2016 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] accessibilité
[Termes IGN] Amsterdam (Pays-Bas)
[Termes IGN] cartographie urbaine
[Termes IGN] distribution spatiale
[Termes IGN] données spatiotemporelles
[Termes IGN] dynamique spatiale
[Termes IGN] gestion urbaine
[Termes IGN] limite indéterminée
[Termes IGN] WebSIG
[Vedettes matières IGN] GéovisualisationRésumé : (auteur) Maps are widely used to provide urban managers with information on critical urban issues such as deprivation, unemployment, and segregation. Although administrative boundaries have always played an important role in map making, they are not meaningful for revealing the spatial dynamics of urban phenomena that vary within wards, cross ward boundaries and do not necessarily stop at the city boundary.
Recently, very detailed (spatial) data have become available providing opportunities for new types of urban mapping. To process these data into meaningful maps, three aspects are important. First, information on maps should be produced at a spatial scale that is relevant for a particular urban phenomenon. Second, to reveal and monitor urban dynamics, maps of a phenomenon at different moments in time are needed. Finally, to accommodate access to these maps for potential users without (much) expertise in mapping, they should be provided through an easy to use tool.
The Regional Monitor Amsterdam (RMA), an online GIS application, deals with these aspects. The purposes of this paper are to explain the mapping methodology adopted in the RMA and to illustrate the usefulness of the tool in urban management. This methodology goes beyond administrative mapping areas with fixed boundaries by introducing ‘data-driven dynamic geographies’. We argue that this methodology produces relevant information by recognizing the scale at which urban phenomena occur. The monitoring tool assists in answering policy questions by easy access to relevant maps for different moments in time.Numéro de notice : A2016--049 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.4000/belgeo.17740 En ligne : https://doi.org/10.4000/belgeo.17740 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84144
in Belgeo > vol 2016 n° 2 (2016-2)[article]Usability evaluation of centered time cartograms / Rehmat Ullah in Open geosciences, vol 8 n° 1 (January - July 2016)
[article]
Titre : Usability evaluation of centered time cartograms Type de document : Article/Communication Auteurs : Rehmat Ullah, Auteur ; Eskedar Zelalem Mengistu, Auteur ; Corné P.J.M. Van Elzakker, Auteur ; Menno-Jan Kraak, Auteur Année de publication : 2016 Article en page(s) : pp 337 - 359 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] cartogramme
[Termes IGN] convivialité
[Termes IGN] oculométrie
[Termes IGN] Pays-Bas
[Termes IGN] réseau ferroviaire
[Termes IGN] temps
[Vedettes matières IGN] GéovisualisationRésumé : (auteur) A time cartogram visualizes travelling-times between locations. It replaces the geographic distance by time distance and distorts the underlyingmap accordingly. By distorting themap, time cartogramsmay give a more intuitive and clear picture of travelling-times. The distortion of the map, however, can make time cartograms harder to recognize and use. Although cartograms are becoming widespread in use, very little is known about their usability. This study focuses on the usability of centered time cartograms: time cartograms that visualize travellingtimes from a fixed starting location to other destinations in a region. We created several centered time cartograms to answer spatio-temporal questions related to the Dutch railway network. Two experiments were performed: a laboratory test and an online survey. In the laboratory test, we used eye-tracking, thinking aloud, and video-recording to compare four different designs of centered time cartograms to find out which one (or combination) of these performs better in answering spatiotemporal questions and thus, to establish a favorable design strategy for these cartograms. In the online survey, centered time cartograms were evaluated against a geographic and schematic map for accuracy, response time, and preference. The first experiment suggested that among various designs, the centered time cartogram with emphasized railroads is the most preferred design and the centered time cartogram without railroads is the least preferred. The second experiment indicated that overall, centered time cartograms perform better than the two other solutions in performing spatio-temporal tasks, particularly when the task has a dominant time-related component. Numéro de notice : A2016--069 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1515/geo-2016-0035 En ligne : https://doi.org/10.1515/geo-2016-0035 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84415
in Open geosciences > vol 8 n° 1 (January - July 2016) . - pp 337 - 359[article]Vers une agriculture multifonctionnelle ? / Laurie Vandevelde in Géomètre, n° 2134 (mars 2016)PermalinkDetection, segmentation and localization of individual trees from MMS point cloud data / Martin Weinmann (2016)PermalinkSemantically enriching point clouds / Merwin Rook in GIM international [en ligne], vol 30 n° 1 (January 2016)PermalinkA synergy method to improve ensemble weather predictions and differential SAR interferograms / Franz-Georg Ulmer in ISPRS Journal of photogrammetry and remote sensing, vol 109 (November 2015)PermalinkAn alternative method to constructing time cartograms for the visual representation of scheduled movement data / Rehmat Ullah in Journal of maps, vol 11 n° 4 ([01/08/2015])PermalinkCityGML implementation specifications for a countrywide 3D dataset: The case of the Netherlands / Jantien E. Stoter in Photogrammetric Engineering & Remote Sensing, PERS, vol 80 n° 11 (November 2014)PermalinkFully automated generalization of a 1:50k map from 1:10k data / Jantien E. Stoter in Cartography and Geographic Information Science, vol 41 n° 1 (January 2014)PermalinkMapping a priori defined plant associations using remotely sensed vegetation characteristics / Hans D. Rölofsen in Remote sensing of environment, vol 140 (January 2014)PermalinkUML-based approach to developing a CityGML application domain extension / Linda Van Den Brink in Transactions in GIS, vol 17 n° 6 (December 2013)PermalinkA sky status indicator to detect rain-affected atmospheric thermal emissions observed at ground / Ada Vittoria Bosisio in IEEE Transactions on geoscience and remote sensing, vol 51 n° 9 (September 2013)Permalink