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Positional accuracy improvement using empirical analytic functions / C. Lopez-Vasquez in Cartography and Geographic Information Science, vol 39 n° 3 (July 2012)  

Public [article]  inCartography and Geographic Information Science > vol 39 n° 3 (July 2012) . - pp 133 - 139 Titre : Positional accuracy improvement using empirical analytic functions Type de document : Article/Communication Auteurs : C. Lopez-Vasquez, Auteur Année de publication : 2012 Article en page(s) : pp 133 - 139 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Projections [Termes IGN] fonction analytique [Termes IGN] point d'appui [Termes IGN] positionnement par GNSS [Termes IGN] précision du positionnement [Termes IGN] projection conforme [Termes IGN] transformation de coordonnées Résumé : (Auteur) We define as Positional Accuracy Improvement the problem of putting together maps A and B of the same area, with B of higher planimetric accuracy. To do so, all objects in A might have to be slightly moved according to a mathematical transformation. Such transformation might ideally be of a specific type, like analytical or conformal functions. We have developed a theory to find a suitable analytical transformation despite it is not well defined because the only data available is the displacement vectors at a limited number of homologue control points. There exists a similar problem in fluid mechanics devoted on estimating the complete velocity field given just values at a limited number of points. We borrowed some ideas from there and introduced them into the positional accuracy improvement problem. We shall demonstrate that it is possible to numerically estimate an analytic function that resembles the given displacement at control points. As a byproduct, an uncertainty estimation is produced, which might help to detect regions of different lineage. The theory has been applied to rural 1:50.000 cartography of Uruguay while trying to diminish the discrepancies against GNSS readings. After the analytic transformation, the RMSE error diminished from 116m to 48 m. Other problems with similar math requirements are the transformation between geodetic control networks. Numéro de notice : A2012-490 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/POSITIONNEMENT Nature : Article DOI : 10.1559/15230406393133 En ligne : https://doi.org/10.1559/15230406393133 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31936 [article]

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A hybrid system of expanding 2D GIS into 3D space / L. Yu in Cartography and Geographic Information Science, vol 39 n° 3 (July 2012)  

Public [article]  inCartography and Geographic Information Science > vol 39 n° 3 (July 2012) . - pp 140 - 153 Titre : A hybrid system of expanding 2D GIS into 3D space Type de document : Article/Communication Auteurs : L. Yu, Auteur ; D. Sun, Auteur ; Z. Peng, Auteur ; Jian Zhang, Auteur Année de publication : 2012 Article en page(s) : pp 140 - 153 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique [Termes IGN] analyse spatiale [Termes IGN] SIG 2D [Termes IGN] système d'information géographique [Termes IGN] visualisation 3D Résumé : (Auteur) A hybrid system that integrates two-dimensional (2D) GIS and three-dimensional (3D) visualization has been developed to provide unique solutions to application domains where traditional 2D GIS and 3D visualization cannot alone provide a solution. In this paper, we focus on three key issues in realizing such an integrated system, including large-scale terrain rendering, 2D and 3D combination display (for example, rendering 2D GIS layers in 3D space), expanding traditional 2D GIS analysis functions into a 3D environment, and visualizing 3D geographical data. A generic framework is developed to integrate 3D visualization with various types of 2D GIS, such as commercial GIS software, open source GIS software and spatial databases. A prototype 2D and 3D hybrid system that seamlessly integrates 2D GIS (developed with ArcEngine) and 3D rendering engine (developed with DirectX) is then developed based on the framework. In this hybrid system, 2D and 3D data are viewed within the same scene. Multiple 2D GIS layers are overlaid on the base terrain using a Level of Detail (LOD) model. Advanced query functions, data accessing, data management and spatial analysis, which are executed in the traditional 2D GIS, are provided to users in a 3D environment by continuously transforming information between the 2D GIS subsystem and the 3D subsystem. The 3D data are organized and displayed by Keyhole Markup Language (KML) and textured 3D models in the COLLAborative Design Activity (COLLADA)*format. The prototype demonstrates that this hybrid system has effectively addressed the three key issues identified above and that it can seamlessly integrate 2D GIS and 3D visualization. The hybrid system has great potential to be employed in many application domains, such as urban planning, landscape design and environmental decision making, among others, to enhance the 3D design capability and facilitate public participation in the planning, design and decision-making process. Numéro de notice : A2012-491 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1559/15230406393140 En ligne : https://doi.org/10.1559/15230406393140 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31937 [article]

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"Yu laid out the lands": georeferencing the Chinese Yujitu (Map of the Tracks of Yu) of 1136 / A. Akin in Cartography and Geographic Information Science, vol 39 n° 3 (July 2012)  

Public [article]  inCartography and Geographic Information Science > vol 39 n° 3 (July 2012) . - pp 154 - 169 Titre : "Yu laid out the lands": georeferencing the Chinese Yujitu (Map of the Tracks of Yu) of 1136 Type de document : Article/Communication Auteurs : A. Akin, Auteur ; D. Mumford, Auteur Année de publication : 2012 Article en page(s) : pp 154 - 169 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] analyse comparative [Termes IGN] carte ancienne [Termes IGN] géoréférencement [Termes IGN] point de repère Résumé : (Auteur) In an historically contextualized overview of the earliest extant version of the Tujitu, engraved on stone under the Liu Yu regime but believed to be a copy of a Northern Song map, the paper analyzes factors that complicate its georeferencing. The paper introduces a new algorithm for nonlinear georeferencing, applying it to 45 points and finding that the placement of sites on the north-south axis must have been based on latitudinal observation. Despite the Yujitu's startlingly modern appearance, the paper finds that there are areas in which it reflects a loyalty to classical texts. Numéro de notice : A2012-492 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1559/15230406393154 En ligne : https://doi.org/10.1559/15230406393154 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31938 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
032-2012031	RAB	Revue	Centre de documentation	En réserve L003	Disponible