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Local terrain modification method considering physical feature constraints for vector elements / Jiangfeng She in Cartography and Geographic Information Science, Vol 47 n° 5 (September 2020)  

Public [article]  inCartography and Geographic Information Science > Vol 47 n° 5 (September 2020) . - pp 452 - 470 Titre : Local terrain modification method considering physical feature constraints for vector elements Type de document : Article/Communication Auteurs : Jiangfeng She, Auteur ; Junyan Liu, Auteur ; Junzhong Tan, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 452 - 470 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] altitude [Termes IGN] analyse vectorielle [Termes IGN] contrainte d'intégrité [Termes IGN] déformation de surface [Termes IGN] données vectorielles [Termes IGN] interpolation [Termes IGN] processeur graphique [Termes IGN] rastérisation [Termes IGN] relief [Termes IGN] superposition de données [Termes IGN] surface du sol [Termes IGN] terrain [Termes IGN] traitement parallèle [Termes IGN] zone tampon Résumé : (auteur) Many studies have been focused on rendering 2D vector elements on 3D terrain, and a series of algorithms have been proposed. Most of these algorithms struggle to provide a seamless overlay between vector elements and an irregular terrain surface. Despite their importance, the physical characteristics of vector elements are often ignored, which distorts the surface of vector elements. For example, if vector elements that represent roads and rivers are simply overlaid on terrain, the phenomena of uneven surfaces and rivers going uphill may occur because of elevation fluctuation. To correct these deficiencies, terrain should be modified according to the physical characteristics of vectors. We propose a local terrain modification method: First, the elevation of terrain covered by vector elements is recalculated according to vectors’ physical characteristics. Second, the multigrid method is used to realize a smooth transition between the modified terrain and its surrounding area. Finally, by setting different transition ranges and comparing the visualization effects, rules are given for the selection of a suitable range. After modification, the terrain conforms to vectors’ physical characteristics, and the overall relief is undamaged. The proposed method was applied to a CPU–GPU parallel heterogeneous model and demonstrated a high level of performance. Numéro de notice : A2020-489 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/MATHEMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/15230406.2020.1770128 Date de publication en ligne : 06/07/2020 En ligne : https://doi.org/10.1080/15230406.2020.1770128 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95660 [article]

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Kalman filtering with state constraints applied to multi-sensor systems and georeferencing / Sören Vogel (2020)  

Public Titre : Kalman filtering with state constraints applied to multi-sensor systems and georeferencing Type de document : Thèse/HDR Auteurs : Sören Vogel, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 2020 Collection : DGK - C, ISSN 0065-5325 num. 856 Importance : 144 p. ISBN/ISSN/EAN : 978-3-7696-5268-0 Note générale : bibliographie Diese Arbeit ist gleichzeitig veröffentlicht in: Wissenschaftliche Arbeiten der Fachrichtung Geodäsie und Geoinformatik der Universität Hannover ISSN 0174-1454, Nr. 364, 2020 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] contrainte d'intégrité [Termes IGN] convolution (signal) [Termes IGN] étalonnage de capteur (imagerie) [Termes IGN] géoréférencement direct [Termes IGN] positionnement cinématique [Termes IGN] programmation par contraintes Résumé : (auteur) Active research on the development of autonomous vehicles has been carried out for several years now. However, some significant challenges still need to be solved in this context. Particularly relevant is the constant guarantee and assurance of the integrity of such autonomous systems. In order to ensure safe manoeuvring in the direct environment of humans, an accurate, precise, reliable and continuous determination of the vehicle’s position and orientation is mandatory. In geodesy, this process is also referred to as georeferencing with respect to a superordinate earth-fixed coordinate system. Especially for complex inner-city areas, there are no fully reliable methods available so far. The otherwise suitable and therefore common Global Navigation Satellite System (GNSS) observations can fail in urban canyons. However, this fact does not only apply exclusively to autonomous vehicles but can generally also be transferred to any kinematic Multi-Sensor System (MSS) operating within challenging environments. Especially in geodesy, there are many MSSs, which require accurate and reliable georeferencing regardless of the environment. This is indispensable for derived subsequent products, such as highly accurate three-dimensional point clouds for 3D city models or Building Information Modelling (BIM) applications. The demand for new georeferencing methods under aspects of integrity also involves the applicability of big data. Modern sensors for capturing the environment, e.g. laser scanners or cameras, are becoming increasingly cheaper and also offer higher information density and accuracy. For many kinematic MSSs, this change leads to a steady increase in the amount of acquired observation data. Many of the currently methods used are not suitable for processing such amounts of data, and instead, they only use a random subset. Besides, big data also influences potential requirements with regard to possible real-time applications. If there is no excessive computing power available to take into account the vast amounts of observation data, recursive methods are usually recommended. In this case, an iterative estimation of the requested quantities is performed, whereby the comprehensive total data set is divided into several individual epochs. If the most recent observations are successively available for each epoch, a filtering algorithm can be applied. Thus, an efficient estimation is carried out and, with respect to a comprehensive overall adjustment, generally larger observation sets can be considered. However, such filtering algorithms exist so far almost exclusively for explicit relations between the available observations and the requested estimation quantities. If this mathematical relationship is implicit, which is certainly the case for several practical issues, only a few methods exist or, in the case of recursive parameter estimation, none at all. This circumstance is accompanied by the fact that the combination of implicit relationships with constraints regarding the parameters to be estimated has not yet been investigated at all. In this thesis, a versatile filter algorithm is presented, which is valid for explicit and for implicit mathematical relations as well. For the first time, methods for the consideration of constraints are given, especially for implicit relations. The developed methodology will be comprehensively validated and evaluated by simulations and real-world application examples of practical relevance. The usage of real data is directly related to kinematic MSSs and the related tasks of calibration and georeferencing. The latter especially with regard to complex innercity environments. In such challenging environments, the requirements for georeferencing under integrity aspects are of special importance. Therefore, the simultaneous use of independent and complementary information sources is applied in this thesis. This enables a reliable georeferencing solution to be achieved and a prompt notification to be issued in case of integrity violations. Note de contenu : 1- Introduction 2- Fundamentals of Recursive State-space Filtering 3- Methodological contributions 4- Kinematic Multi-sensor Systems and Their Efficient Calibration 5- Information-based Georeferencing 6- Conclusions Numéro de notice : 17686 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Thèse étrangère Note de thèse : PhD thesis : Geodäsie und Geoinformatik : Hanovre : 2020 DOI : sans En ligne : https://dgk.badw.de/fileadmin/user_upload/Files/DGK/docs/c-856.pdf Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98164

Query rewriting for semantic query optimization in spatial databases / Eduardo Mella in Geoinformatica [en ligne], vol 23 n° 1 (January 2019)  

Public [article]  inGeoinformatica [en ligne] > vol 23 n° 1 (January 2019) . - pp 79 - 104 Titre : Query rewriting for semantic query optimization in spatial databases Type de document : Article/Communication Auteurs : Eduardo Mella, Auteur ; M. Andrea Rodríguez, Auteur ; Loreto Bravo, Auteur ; Diego Gatica, Auteur Année de publication : 2019 Article en page(s) : pp 79 - 104 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] contrainte d'intégrité [Termes IGN] jointure spatiale [Termes IGN] optimisation (mathématiques) [Termes IGN] programmation par contraintes [Termes IGN] relation topologique [Termes IGN] requête (informatique) [Termes IGN] requête spatiale [Termes IGN] système de gestion de bases de données orientées objet Résumé : (auteur) Query processing is an important challenge for spatial databases due to the use of complex data types that represent spatial attributes. In particular, due to the cost of spatial joins, several optimization algorithms based on indexing structures exist. The work in this paper proposes a strategy for semantic query optimization of spatial join queries. The strategy detects queries with empty results and rewrites queries to eliminate unnecessary spatial joins or to replace spatial by thematic joins. This is done automatically by analyzing the semantics imposed by the database schema through topological dependencies and topological referential integrity constraints. In this way, the strategy comes to complement current state-of-art algorithms for processing spatial join queries. The experimental evaluation with real data sets shows that the optimization strategy can achieve a decrease in the time cost of a join query using indexing structures in a spatial database management system (SDBMS). Numéro de notice : A2019-224 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10707-018-00335-w Date de publication en ligne : 04/01/2019 En ligne : http://dx.doi.org/10.1007/s10707-018-00335-w Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92623 [article]

Cohérence logique dans les systèmes OLAP spatiaux : un état de l’art / Sandro Bimonte in Revue internationale de géomatique, vol 26 n° 1 (janvier - mars 2016)  

Public [article]  inRevue internationale de géomatique > vol 26 n° 1 (janvier - mars 2016) . - pp 97-131 Titre : Cohérence logique dans les systèmes OLAP spatiaux : un état de l’art Type de document : Article/Communication Auteurs : Sandro Bimonte, Auteur ; Kamal Boulil, Auteur ; François Pinet, Auteur Année de publication : 2016 Article en page(s) : pp 97-131 Note générale : Bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] cohérence logique [Termes IGN] contrainte d'intégrité [Termes IGN] données localisées [Termes IGN] données multidimensionnelles [Termes IGN] état de l'art [Termes IGN] OLAP [Termes IGN] qualité des données [Termes IGN] SOLAP Résumé : (Auteur) Les systèmes d’Entrepôts de Données et « OnLine Analytical Process » spatiaux (EDS et SOLAP) sont des technologies d’aide à la décision permettant l’agrégation et l’analyse multidimensionnelle de gros volumes de données spatiales. La qualité des données entreposées dépend de critères comme la précision, l’exhaustivité et la cohérence logique. Dans cet article, nous présentons un état de l’art et des travaux sur la définition des contraintes d’intégrité pour garantir la cohérence logique au niveau des trois composantes (données, agrégations, et requêtes) au sein des EDS, ainsi qu’une évaluation de ces travaux et de notre proposition par rapport à un ensemble de critères que nous avons définis. Numéro de notice : A2016-326 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.3166/RIG.26.97-131 Date de publication en ligne : 11/04/2016 En ligne : https://doi.org/10.3166/RIG.26.97-131 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80948 [article]

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Constrained least squares algorithms for nonlinear unmixing of hyperspectral imagery / Hanye Pu in IEEE Transactions on geoscience and remote sensing, vol 53 n° 3 (March 2015)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 53 n° 3 (March 2015) . - pp 1287 - 1303 Titre : Constrained least squares algorithms for nonlinear unmixing of hyperspectral imagery Type de document : Article/Communication Auteurs : Hanye Pu, Auteur ; Zhao Chen, Auteur ; Bin Wang, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 1287 - 1303 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] analyse des mélanges spectraux [Termes IGN] contrainte d'intégrité [Termes IGN] image hyperspectrale [Termes IGN] méthode des moindres carrés Résumé : (Auteur) Hyperspectral unmixing is an important issue in hyperspectral image processing. In this paper, we transform the unmixing problem into a constrained nonlinear least squares (CNLS) problem by introducing the abundance sum-to-one constraint, abundance nonnegative constraint, and bound constraints on nonlinearity parameters. The new CNLS-based algorithms assume that the mixing mechanism of each observed pixel can be described by two forms. One is a sum of linear mixtures of endmember spectra and nonlinear variations in reflectance, and the other is a joint mixture resulting from the linearity and nonlinearity in hyperspectral data. For the former, an alternating iterative optimization algorithm is developed to solve the problem of CNLS. As for the latter, the structured total least squares optimization approach is used to obtain the abundance vectors and nonlinearity parameters simultaneously. Current mixing models can be interpreted by either or both of these two mechanisms. A comparative analysis based on Monte Carlo simulations and real data experiments is conducted to evaluate the proposed algorithms and five other state-of-the-art algorithms. Experimental results show that the proposed algorithms give outstanding performance of hyperspectral nonlinear unmixing for both synthetic data and real hyperspectral images, as satisfactory accuracy in term of abundance fractions and low computational complexity are observed. Numéro de notice : A2015-131 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2014.2336858 Date de publication en ligne : 30/07/2014 En ligne : https://doi.org/10.1109/TGRS.2014.2336858 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75794 [article]

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Rank-based strategies for cleaning inconsistent spatial databases / Nieves R. Brisaboa in International journal of geographical information science IJGIS, vol 29 n° 2 (February 2015)  

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Adaptive geo-information processing service evolution: Reuse and local modification method / Haifeng Li in ISPRS Journal of photogrammetry and remote sensing, vol 83 (September 2013)

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Generalized inner constraints for geodetic network densification problems / C. Kotsakis in Journal of geodesy, vol 87 n° 7 (July 2013)  

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A framework to model and manipulate constraints for over-constrained geographic applications / Wassim Jaziri in Geoinformatica, vol 17 n° 2 (April 2013)  

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Transaction rules for updating surfaces in 3D GIS / G. Groger in ISPRS Journal of photogrammetry and remote sensing, vol 69 (April 2012)

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A bundle adjustment approach with inner constraints for the scaled orthographic projection / F. Keith in ISPRS Journal of photogrammetry and remote sensing, vol 66 n° 6 (November 2011)

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Specifications for user generated spatial content / Carmen Brando (2011)  

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OCL for formal modelling of topological modelling constraints involving regions with broad boundaries / L. Bejaoui in Geoinformatica, vol 14 n° 3 (July 2010)  

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Qualified topological relations between spatial objects with possible vague shape / L. Bejaoui in International journal of geographical information science IJGIS, vol 23 n° 7-8 (july 2009)

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Modélisation de contraintes d'intégrité spatiales avec OCL / F. Pinet in Revue internationale de géomatique, vol 19 n° 1 (mars – mai 2009)  

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