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Optimum stochastic modeling for GNSS tropospheric delay estimation in real-time / Tomasz Hadas in GPS solutions, vol 21 n° 3 (July 2017)
[article]
Titre : Optimum stochastic modeling for GNSS tropospheric delay estimation in real-time Type de document : Article/Communication Auteurs : Tomasz Hadas, Auteur ; Felix Norman Teferle, Auteur ; Mathieu Kazmierski, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 1069 – 1081 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] données GNSS
[Termes IGN] optimisation spatiale
[Termes IGN] prévision météorologique
[Termes IGN] retard troposphérique
[Termes IGN] retard troposphérique zénithal
[Termes IGN] station GNSSRésumé : (auteur) In GNSS data processing, the station height, receiver clock and tropospheric delay (ZTD) are highly correlated to each other. Although the zenith hydrostatic delay of the troposphere can be provided with sufficient accuracy, zenith wet delay (ZWD) has to be estimated, which is usually done in a random walk process. Since ZWD temporal variation depends on the water vapor content in the atmosphere, it seems to be reasonable that ZWD constraints in GNSS processing should be geographically and/or time dependent. We propose to take benefit from numerical weather prediction models to define optimum random walk process noise. In the first approach, we used archived VMF1-G data to calculate a grid of yearly and monthly means of the difference of ZWD between two consecutive epochs divided by the root square of the time lapsed, which can be considered as a random walk process noise. Alternatively, we used the Global Forecast System model from National Centres for Environmental Prediction to calculate random walk process noise dynamically in real-time. We performed two representative experimental campaigns with 20 globally distributed International GNSS Service (IGS) stations and compared real-time ZTD estimates with the official ZTD product from the IGS. With both our approaches, we obtained an improvement of up to 10% in accuracy of the ZTD estimates compared to any uniformly fixed random walk process noise applied for all stations. Numéro de notice : A2017-443 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-016-0595-0 En ligne : https://doi.org/10.1007/s10291-016-0595-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86365
in GPS solutions > vol 21 n° 3 (July 2017) . - pp 1069 – 1081[article]Optimal placement of a terrestrial laser scanner with an emphasis on reducing occlusions / Morteza Heidari Mozaffar in Photogrammetric record, vol 31 n° 156 (December 2016 - February 2017)
[article]
Titre : Optimal placement of a terrestrial laser scanner with an emphasis on reducing occlusions Type de document : Article/Communication Auteurs : Morteza Heidari Mozaffar, Auteur ; Masood Varshosaz, Auteur Année de publication : 2016 Article en page(s) : pp 374 – 393 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] angle de visée
[Termes IGN] occultation du signal
[Termes IGN] optimisation spatiale
[Termes IGN] point de visibilité
[Termes IGN] semis de points
[Termes IGN] télémétrie laser terrestreRésumé : (auteur) In this paper, a new automated algorithm is proposed that finds the optimum locations of a terrestrial laser scanner (TLS), ensuring completeness of data and minimising the number of scanning locations. The process starts with an initial scan and placing a 3D grid of candidate stations over the entire scan area. A global visibility analysis is then performed to identify the next best view (NBV) location. The TLS is placed on this selected point and a new scan is recorded. Having updated the initial scan with the resulting point cloud, the model is checked for completeness and density. The process is repeated until full coverage of the scan area is achieved by determining the best global arrangement with the minimum number of stations. Experiments show that the algorithm is able to automatically determine the station positions and provide a coverage of 99·5% for simulated data and 91% for real data. Numéro de notice : A2016--002 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/phor.12162 Date de publication en ligne : 15/12/2016 En ligne : https://doi.org/10.1111/phor.12162 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83820
in Photogrammetric record > vol 31 n° 156 (December 2016 - February 2017) . - pp 374 – 393[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 106-2016041 RAB Revue Centre de documentation En réserve L003 Disponible Hybrid BD / GPS positioning for deformation monitoring under denied environments / Zhenzhong Peng in Journal of applied geodesy, vol 10 n° 3 (September 2016)
[article]
Titre : Hybrid BD / GPS positioning for deformation monitoring under denied environments Type de document : Article/Communication Auteurs : Zhenzhong Peng, Auteur ; Qianxia Li, Auteur ; Linyuan Xia, Auteur Année de publication : 2016 Article en page(s) : pp 159 – 166 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Topographie
[Termes IGN] analyse de sensibilité
[Termes IGN] auscultation d'ouvrage
[Termes IGN] barrage
[Termes IGN] optimisation spatiale
[Termes IGN] positionnement par BeiDou
[Termes IGN] positionnement par GNSS
[Termes IGN] positionnement par GPS
[Termes IGN] surveillance d'ouvrage
[Termes IGN] surveillance géologique
[Termes IGN] topométrie de précisionRésumé : (auteur) In the era of multiple satellite navigation and positioning, there are still many remained issues to be tackled in order to satisfy varied applications for various sectors. These include availability, accuracy, integrity, vulnerability and others. To explore feasibility of deformation monitoring under dam and steep slope environments, we investigated features of hybrid BD / GPS positioning and monitoring performance. Results indicate that hybrid satellites can further facilitate precise positioning for deformation monitoring on restricted regions. A static network in near real time mode is designed to exhibit essential sensitivity for deformation monitoring under different network connectivity. Analysis shows that under given network design matrix, contributions from hybrid BD / GPS have enhanced network sensitivity and ensured monitoring performance under challenged scenarios. Related tests combining with application to stringent dam monitoring have been conducted to exemplify sensitivity changes along vital engineering directions and optimal schemes for network configuration. Numéro de notice : A2016-969 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2016-0002 En ligne : https://doi.org/10.1515/jag-2016-0002 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83675
in Journal of applied geodesy > vol 10 n° 3 (September 2016) . - pp 159 – 166[article]Estimating spatial efficiency using cyber search, GIS, and spatial optimization: a case study of fire service deployment in Los Angeles County / R.L. Church in International journal of geographical information science IJGIS, vol 30 n° 3-4 (March - April 2016)
[article]
Titre : Estimating spatial efficiency using cyber search, GIS, and spatial optimization: a case study of fire service deployment in Los Angeles County Type de document : Article/Communication Auteurs : R.L. Church, Auteur ; Wenwen Li, Auteur Année de publication : 2016 Article en page(s) : pp 535 - 553 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web
[Termes IGN] couverture (données géographiques)
[Termes IGN] évaluation
[Termes IGN] Los Angeles
[Termes IGN] lutte contre l'incendie
[Termes IGN] optimisation spatiale
[Termes IGN] précision de localisation
[Termes IGN] système d'information géographiqueRésumé : (Auteur) The efficiency of public investments and services has been of interest to geographic researchers for several decades. While in the private sector inefficiency often leads to higher prices, loss of competitiveness, and loss of business, in the public sector inefficiency in service provision does not necessarily lead to immediate changes. In many cases, it is not an entirely easy task to analyze a particular service as appropriate data may be difficult to obtain and hidden in detailed budgets. In this paper, we develop an integrative approach that uses cyber search, Geographic Information System (GIS), and spatial optimization to estimate the spatial efficiency of fire protection services in Los Angeles (LA) County. We develop a cyber-search process to identify current deployment patterns of fire stations across the major urban region of LA County. We compare the results of our search to existing databases. Using spatial optimization, we estimate the level of deployment that is needed to meet desired coverage levels based upon the location of an ideal fire station pattern, and then compare this ideal level of deployment to the existing system as a means of estimating spatial efficiency. GIS is adopted throughout the paper to simulate the demand locations, to conduct location-based spatial analysis, to visualize fire station data, and to map model simulation results. Finally, we show that the existing system in LA County has considerable room for improvement. The methodology presented in this paper is both novel and groundbreaking, and the automated assessments are readily transferable to other counties and jurisdictions. Numéro de notice : A2016--062 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2015.1083572 En ligne : https://doi.org/10.1080/13658816.2015.1083572 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79890
in International journal of geographical information science IJGIS > vol 30 n° 3-4 (March - April 2016) . - pp 535 - 553[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 079-2016021 RAB Revue Centre de documentation En réserve L003 Disponible A parallel algorithm for coverage optimization on multi-core architectures / Ran Wei in International journal of geographical information science IJGIS, vol 30 n° 3-4 (March - April 2016)
[article]
Titre : A parallel algorithm for coverage optimization on multi-core architectures Type de document : Article/Communication Auteurs : Ran Wei, Auteur ; Alan T. Murray, Auteur Année de publication : 2016 Article en page(s) : pp 432 - 450 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] architecture de système
[Termes IGN] Californie (Etats-Unis)
[Termes IGN] couverture (données géographiques)
[Termes IGN] cyberinfrastructure
[Termes IGN] Ohio (Etats-Unis)
[Termes IGN] optimisation spatiale
[Termes IGN] système d'information géographique
[Termes IGN] traitement parallèleRésumé : (Auteur) Location siting is an important part of service provision, with much potential to impact operational efficiency, safety, security, system reliability, etc. A class of location models seeks to optimize coverage of demand for service that is continuously distributed across space. Decision-making and planning contexts include police/fire resource allocation for a community, siting cellular towers to support cell phone signal transmission, locating emergency warning sirens to alert the public of severe weather and other related dangers, and many others as well. When facilities can be sited anywhere in continuous space to provide coverage to an entire region, this is a very computationally challenging problem to solve because potential demand for service is everywhere and there are an infinite number of potential facility sites to consider. This article develops a new parallel solution approach for this location coverage optimization problem through an iterative bounding scheme on multi-core architectures. The developed approach is applied to site emergency warning sirens in Dublin, Ohio, and fire stations in Elk Grove, California. Results demonstrate the effectiveness and efficiency of the proposed approach, enabling real-time analysis and planning. This work illustrates that the integration of cyberinfrastructure can significantly improve computational efficiency in solving challenging spatial optimization problems, fitting the themes of this special issue: cyberinfrastructure, GIS, and spatial optimization. Numéro de notice : A2016-202 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2015.1030750 En ligne : https://doi.org/10.1080/13658816.2015.1030750 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79888
in International journal of geographical information science IJGIS > vol 30 n° 3-4 (March - April 2016) . - pp 432 - 450[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 079-2016021 RAB Revue Centre de documentation En réserve L003 Disponible Spatial optimization for regionalization problems with spatial interaction: a heuristic approach / Kamyoung Kim in International journal of geographical information science IJGIS, vol 30 n° 3-4 (March - April 2016)PermalinkA Landsat data tiling and compositing approach optimized for change detection in the conterminous United States / Kurtis J. Nelson in Photogrammetric Engineering & Remote Sensing, PERS, vol 81 n° 7 (July 2015)Permalink