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Parameterisation of the GNSS troposphere tomography domain with optimisation of the nodes’ distribution / Estera Trzcina in Journal of geodesy, vol 97 n° 1 (January 2023)  

Public [article]  inJournal of geodesy > vol 97 n° 1 (January 2023) . - n° 2 Titre : Parameterisation of the GNSS troposphere tomography domain with optimisation of the nodes’ distribution Type de document : Article/Communication Auteurs : Estera Trzcina, Auteur ; Witold Rohm, Auteur ; Kamil Smolak, Auteur Année de publication : 2023 Article en page(s) : n° 2 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] données GNSS [Termes IGN] interpolation bilinéaire [Termes IGN] modèle météorologique [Termes IGN] optimisation (mathématiques) [Termes IGN] radiosondage [Termes IGN] récepteur GNSS [Termes IGN] retard troposphérique [Termes IGN] retard troposphérique zénithal [Termes IGN] système de grille globale discrète [Termes IGN] teneur en vapeur d'eau [Termes IGN] tomographie [Termes IGN] troposphère Résumé : (auteur) Water vapour is a highly variable constituent of the troposphere; thus, its high-resolution measurements are of great importance to weather prediction systems. The Global Navigation Satellite Systems (GNSS) are operationally used in the estimation of the tropospheric state and assimilation of the results into the weather models. One of the GNSS techniques of troposphere sensing is tomography which provides 3-D fields of wet refractivity. The tomographic results have been successfully assimilated into the numerical weather models, showing the great potential of this technique. The GNSS tomography can be based on two different approaches to the parameterisation of the model’s domain, i.e. block (voxel-based) or grid (node-based) approach. Regardless of the parameterisation approach, the tomographic domain should be discretised, which is usually performed in a regular manner, with a grid resolution depending on the mean distance between the GNSS receivers. In this work, we propose a new parameterisation approach based on the optimisation of the tomographic nodes’ location, taking into account the non-uniform distribution of the GNSS information in the troposphere. The experiment was performed using a dense network of 16 low-cost multi-GNSS receivers located in Wrocław and its suburbs, with a mean distance of 3 km. Cross-validation of four different parameterisation approaches is presented. The validation is performed based on the Weather Research and Forecasting model as well as radiosonde observations. The new approach improves the results of wet refractivity estimation by 0.5–2 ppm in terms of RMSE, especially for altitudes of 0.5–2.0 km. Numéro de notice : A2023-044 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : https://doi.org/10.1007/s00190-022-01691-0 Date de publication en ligne : 30/12/2022 En ligne : https://doi.org/10.1007/s00190-022-01691-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102343 [article]

The employment of quasi-hexagonal grids in spherical harmonic analysis and synthesis for the earth's gravity field / Xingxing Li in Journal of geodesy, vol 96 n° 11 (November 2022)  

Public [article]  inJournal of geodesy > vol 96 n° 11 (November 2022) . - n° 89 Titre : The employment of quasi-hexagonal grids in spherical harmonic analysis and synthesis for the earth's gravity field Type de document : Article/Communication Auteurs : Xingxing Li, Auteur ; Jiancheng Li, Auteur ; Xiaochong Tong, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 89 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] champ de pesanteur terrestre [Termes IGN] harmonique sphérique [Termes IGN] icosahèdre [Termes IGN] système de grille globale discrète [Termes IGN] théorème de Legendre Résumé : (auteur) Numéro de notice : A2022-837 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-022-01653-6 Date de publication en ligne : 09/11/2022 En ligne : https://doi.org/10.1007/s00190-022-01653-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102034 [article]

Efficient calculation of distance transform on discrete global grid systems / Meysam Kazemi in ISPRS International journal of geo-information, vol 11 n° 6 (June 2022)  

Public [article]  inISPRS International journal of geo-information > vol 11 n° 6 (June 2022) . - n° 322 Titre : Efficient calculation of distance transform on discrete global grid systems Type de document : Article/Communication Auteurs : Meysam Kazemi, Auteur ; Lakin Wecker, Auteur ; Faramarz Samavati, Auteur Année de publication : 2022 Article en page(s) : n° 322 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] ArcGIS [Termes IGN] distance [Termes IGN] données vectorielles [Termes IGN] frontière [Termes IGN] maillage par triangles [Termes IGN] Ontario (Canada) [Termes IGN] sphèroïde [Termes IGN] système d'information géographique [Termes IGN] système de grille globale discrète [Termes IGN] transformation Résumé : (auteur) Numéro de notice : A2022-411 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/ijgi11060322 Date de publication en ligne : 25/05/2022 En ligne : https://doi.org/10.3390/ijgi11060322 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100761 [article]

Integration of heterogeneous terrain data into Discrete Global Grid Systems / Mingke Li in Cartography and Geographic Information Science, vol 48 n° 6 (October 2021)  

Public [article]  inCartography and Geographic Information Science > vol 48 n° 6 (October 2021) . - pp 546 - 564 Titre : Integration of heterogeneous terrain data into Discrete Global Grid Systems Type de document : Article/Communication Auteurs : Mingke Li, Auteur ; Heather McGrath, Auteur ; Emmanuel Stefanakis, Auteur Année de publication : 2021 Article en page(s) : pp 546 - 564 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] données de terrain [Termes IGN] données hétérogènes [Termes IGN] Infrastructure de données [Termes IGN] métadonnées [Termes IGN] modèle numérique de surface [Termes IGN] Ontario (Canada) [Termes IGN] système de grille globale discrète [Termes IGN] tessellation Résumé : (auteur) The Canadian Digital Elevation Model (CDEM) and the High-Resolution Digital Elevation Model (HRDEM) released by Natural Resources Canada are primary terrain data sources in Canada. Due to their different coverage, datums, resolutions, and accuracies, a standardized framework for national elevation data across various scales is required. This study provides new insights into the adoption of Discrete Global Grid Systems (DGGS) to facilitate the integration of multi-source terrain data at various granularities. In particular, the Icosahedral Snyder Equal Area Aperture 3 Hexagonal Grid (ISEA3H) was employed, and quantization, integration, and aggregation were conducted on this framework. To demonstrate the modeling process, an experiment was undertaken for two areas in Ontario, taking advantage of parallel computing which was beneficial from the discreteness of DGGS cells. The accuracy of the modeled elevations was estimated by referring to the ground-surveyed values and was included in the spatially referenced metadata as an indicator of data quality. This research can serve as a guide for future development of a national elevation service, providing consistent, multi-resolution elevations and avoiding complex, duplicated pre-processing at the user’s end. Future investigation into an operational integration platform to support real-world decision-making, as well as the DGGS-powered geospatial datacube, is recommended. Numéro de notice : A2021-748 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/15230406.2021.1966648 Date de publication en ligne : 02/09/2021 En ligne : https://doi.org/10.1080/15230406.2021.1966648 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98711 [article]

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Hexagonal map grids – an experimental study on the performance in memory of object locations / Dennis Edler in Cartography and Geographic Information Science, Vol 46 n° 5 (September 2019)  

Public [article]  inCartography and Geographic Information Science > Vol 46 n° 5 (September 2019) . - pp 401 - 411 Titre : Hexagonal map grids – an experimental study on the performance in memory of object locations Type de document : Article/Communication Auteurs : Dennis Edler, Auteur ; Julian Keil, Auteur ; Anne-Kathrin Bestgen, Auteur ; Lars Kuchinke, Auteur ; Frank Dickmann, Auteur Année de publication : 2019 Article en page(s) : pp 401 - 411 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] carroyage [Termes IGN] carte cognitive [Termes IGN] cognition [Termes IGN] grille [Termes IGN] mémoire [Termes IGN] représentation mentale spatiale [Termes IGN] système de grille globale discrète [Vedettes matières IGN] Cartologie Résumé : (auteur) In various every day contexts, maps are used as media supporting orientation, wayfinding, and navigation tasks. To create highly accurate and reliable maps, cartographers must be aware of cognitive effects that occur when people process map information. Interdisciplinary research from cognitive psychologists showed that map graphics lead to spatial distortions in human spatial memory. These distortions can influence human orientation capacities. Recently, it was discovered that grid structures overlaid on maps help to correct spatial distortions in cognitive representations of geographic space. Square grids chunk a map into smaller units (regions). They guide map-viewing behavior, and their regular structure helps map users to recall learned locations of objects more accurately. The effects caused by square grids may also occur when overlaying other common kinds of geometries, such as hexagonal structures. The effects of hexagonal grid structures on memory of object locations were investigated in this map-experimental study. The study design is based on a recall-memory-paradigm, an established method of experimental psychology to measure performance in memory. The results show that hexagonal grid patterns can improve the performance. Numéro de notice : A2019-425 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/15230406.2018.1496035 Date de publication en ligne : 03/08/2018 En ligne : https://doi.org/10.1080/15230406.2018.1496035 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93557 [article]

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Central place indexing : hierarchical linear indexing systems for mixed-aperture hexagonal discrete global grid systems / Kevin Sahr in Cartographica, vol 54 n° 1 (Spring 2019)  

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Datacubes : A discrete global grid systems perspective / Matthew B.J. Purss in Cartographica, vol 54 n° 1 (Spring 2019)  

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Geospatial data organization methods with emphasis on aperture-3 hexagonal discrete global grid systems / Ali Mahdavi Amiri in Cartographica, vol 54 n° 1 (Spring 2019)  

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Utilizing a discrete global grid system for handling point clouds with varying locations, times, and levels of detail / Neeraj Sirdeshmukh in Cartographica, vol 54 n° 1 (Spring 2019)  

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A virtual globe using a discrete global grid system to illustrate the modifiable areal unit problem / Paulo Raposo in Cartographica, vol 54 n° 1 (Spring 2019)  

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