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A tropospheric delay model to integrate ERA5 and GNSS reference network for mountainous areas: application to precise point positioning / Cuixian Lu in GPS solutions, vol 27 n° 2 (April 2023)  

Public [article]  inGPS solutions > vol 27 n° 2 (April 2023) . - n° 81 Titre : A tropospheric delay model to integrate ERA5 and GNSS reference network for mountainous areas: application to precise point positioning Type de document : Article/Communication Auteurs : Cuixian Lu, Auteur ; Yaxin Zhong, Auteur ; Zhilu Wu, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : n° 81 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] Australie [Termes IGN] Continuously Operating Reference Station network [Termes IGN] convergence [Termes IGN] ERA5 [Termes IGN] montagne [Termes IGN] positionnement ponctuel précis [Termes IGN] retard troposphérique [Termes IGN] retard troposphérique zénithal [Termes IGN] station GNSS [Termes IGN] teneur en vapeur d'eau Résumé : (auteur) In this study, a tropospheric delay model that integrates tropospheric delays derived from the European Centre for Medium-Range Weather Forecasts fifth-generation global atmospheric reanalysis and the Continuously Operating Reference Station (CORS) network observations in mountainous areas is established, which is then applied to improve GNSS precise point positioning (PPP). Observations of GNSS stations in the Great Dividing Range of eastern Australia are selected for the experiments. The performance of zenith wet delay (ZWD) retrieved from the integrated tropospheric model is evaluated with comparisons to precise point positioning (PPP) estimated ZWD values. Results show that the average root-mean-square value for ZWDs of the integrated tropospheric model is 8.03 mm for the eastern Australian CORS network, showing an improvement of 14.0% compared to that of the CORS interpolation model. Besides, the proposed tropospheric model is applied to regional augmentation precise positioning. Results present that the average positioning accuracy of the tropospheric model-corrected PPP solutions is 1.42 cm, 1.39 cm and 2.90 cm for the east, north and vertical components, respectively, revealing an improvement of 14.5%, 11.5% and 18.6% compared to the PPP solutions with regional CORS corrections. Meanwhile, almost all stations can achieve a faster solution convergence by performing the integrated tropospheric model-corrected PPP. All these results demonstrate the promising potential of the proposed tropospheric model in enhancing precise positioning as well as facilitating applications in the meteorological fields. Numéro de notice : A2023-183 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-023-01425-5 Date de publication en ligne : 03/03/2023 En ligne : https://doi.org/10.1007/s10291-023-01425-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102954 [article]

Mapping the anthropic occupation of the territory. Tracing dynamics of human settlement from archaeological records and historic cartographies / Marina López Sánchez in Journal of maps, vol 18 n° 1 (January 2023)  

Public [article]  inJournal of maps > vol 18 n° 1 (January 2023) . - pp 916 - 931 Titre : Mapping the anthropic occupation of the territory. Tracing dynamics of human settlement from archaeological records and historic cartographies Type de document : Article/Communication Auteurs : Marina López Sánchez, Auteur ; Mercedes Linares Gómez Del Pulgar, Auteur ; Antonio Tejedor Cabrera, Auteur Année de publication : 2023 Article en page(s) : pp 916 - 931 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie thématique [Termes IGN] Andalousie [Termes IGN] carte ancienne [Termes IGN] convergence [Termes IGN] données localisées historiques [Termes IGN] gestion du patrimoine [Termes IGN] interconnexion [Termes IGN] patrimoine culturel [Termes IGN] paysage [Termes IGN] site archéologique [Termes IGN] système d'information géographique Résumé : (auteur) The convergence of research on landscape and heritage holds great strategic potential for establishing novel connections between the heritage resources of a territory. This text reflects on the ability of the landscape to situate inherited assets within a framework of spatial coherence in relation to the peri-urban spaces of large cities, heritage areas of great historical depth that have been particularly aggressively exposed to the urban development dynamics of the second half of the twentieth century. In order to address these often forgotten spaces, this text presents a system for heritage management argued from the standpoint of and towards the landscape and based on historical interpretation, cartographic analysis, mapping and digital documentation. Geographic technologies and graphic expression are basic pillars to integrate historical information with the language and resources of the disciplines involved in landscape planning and design, advancing criteria for a forward-looking landscape-based heritage management. Numéro de notice : A2023-053 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/01426397.2021.1921717 Date de publication en ligne : 06/05/2021 En ligne : https://doi.org/10.1080/17445647.2021.2009924 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102385 [article]

Analysis of the spatial range of service and accessibility of hospitals designated for coronavirus disease 2019 in Yunnan Province, China / Liangting Zheng in Geocarto international, vol 37 n° 22 ([10/10/2022])  

Public [article]  inGeocarto international > vol 37 n° 22 [10/10/2022] . - pp 6519 - 6537 Titre : Analysis of the spatial range of service and accessibility of hospitals designated for coronavirus disease 2019 in Yunnan Province, China Type de document : Article/Communication Auteurs : Liangting Zheng, Auteur ; Jia Li, Auteur ; Wenying Hu, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : pp 6519 - 6537 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] accessibilité [Termes IGN] diagramme de Voronoï [Termes IGN] données médicales [Termes IGN] données routières [Termes IGN] épidémie [Termes IGN] interpolation inversement proportionnelle à la distance [Termes IGN] interpolation par pondération de zones [Termes IGN] maladie virale [Termes IGN] médecine humaine [Termes IGN] secours d'urgence [Termes IGN] Yunnan (Chine) Résumé : (auteur) COVID-19 poses a major threat to global health care systems, and the recent surge in mortality rates confirms the importance of timely access to care. The capacity of medical service providers is reflected both in the spatial accessibility of medical institutions and in the spatial scope of their services. Therefore, this study aims to investigate the spatial scope of services and spatial accessibility of COVID-19-designated hospitals in Yunnan Province, China. Data are collected from multiple sources and included COVID-19 case data, road data, and data from designated hospitals for COVID-19 in Yunnan Province. The optimal spatial service range for designated hospitals is delineated using a weighted Voronoi diagram that takes into account the number of medical staff and the number of beds in the hospital. Traffic accessibility coefficients are introduced to analyze the spatial accessibility of COVID-19-designated hospitals, and the spatial accessibility of each designated hospital is visualized using the inverse distance weighting interpolation algorithm. The results show the following: (1) COVID-19 cases in Yunnan Province are concentrated in the central and northern regions. The largest single cells in the weighted Voronoi diagram are mainly Pu'er (59168 km2), Honghe (35569 km2), and Baoshan (46795 km2), and the time cost of attainting medical treatment is greater for residents in marginal areas. (2) Within the service space of designated hospitals, 90.24% of patients could obtain medical assistance within 2 h. Those in 52 (36.36%) counties within a municipal jurisdiction could obtain medical services within 2 h, and 76.47% of counties have above-average spatial accessibility. (3) Medical resources in Yunnan Province should be shifted toward the high-risk east-central region and the less spatially accessible in southern and western regions. Numéro de notice : A2022-728 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2021.1943008 Date de publication en ligne : 09/07/2021 En ligne : https://doi.org/10.1080/10106049.2021.1943008 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101674 [article]

Spherical harmonic synthesis of area-mean potential values on irregular surfaces / Blažej Bucha in Journal of geodesy, vol 96 n° 10 (October 2022)  

Public [article]  inJournal of geodesy > vol 96 n° 10 (October 2022) . - n° 68 Titre : Spherical harmonic synthesis of area-mean potential values on irregular surfaces Type de document : Article/Communication Auteurs : Blažej Bucha, Auteur Année de publication : 2022 Article en page(s) : n° 68 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] champ de gravitation [Termes IGN] convergence [Termes IGN] harmonique sphérique [Termes IGN] surface hétérogène [Termes IGN] transformation de Legendre [Termes IGN] transformation rapide de Fourier Résumé : (auteur) We present a method to integrate external solid spherical harmonic expansions at geographical grids residing on undulated surfaces. It can be used to evaluate area-mean potential values on planetary surfaces that vary within grid cells. This is in contrast with available methods, which assume cells with a constant spherical radius only. When formulating the technique, we took advantage of 2D spherical Fourier methods to improve the computational speed. The price to be paid are high memory requirements, even with moderate maximum harmonic degrees such as 100 (both of the potential and of the irregular surface). In numerical experiments, we validate the method against independent area-mean potential values to prove its correctness. A study of the series behavior below the sphere of convergence shows that the series may diverge on planetary topographies, similarly as it is with its point-value counterpart. The method can be utilized in numerical studies of the change of boundary method, one of the pivotal concepts of recent high-degree models such as EGM2008. A numerical implementation is made available through CHarm, a C library to work with spherical harmonics up to high degrees. CHarm is accessible via https://github.com/blazej-bucha/charm. Numéro de notice : A2022-736 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-022-01658-1 Date de publication en ligne : 27/09/2022 En ligne : https://doi.org/10.1007/s00190-022-01658-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101708 [article]

The iterative convolution–thresholding method (ICTM) for image segmentation / Dong Wang in Pattern recognition, vol 130 (October 2022)  

Public [article]  inPattern recognition > vol 130 (October 2022) . - n° 108794 Titre : The iterative convolution–thresholding method (ICTM) for image segmentation Type de document : Article/Communication Auteurs : Dong Wang, Auteur ; Xiaoping Wang, Auteur Année de publication : 2022 Article en page(s) : n° 108794 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] contour [Termes IGN] convergence [Termes IGN] filtrage numérique d'image [Termes IGN] image à haute résolution [Termes IGN] itération [Termes IGN] segmentation d'image [Termes IGN] seuillage Résumé : (auteur) Variational methods, which have been tremendously successful in image segmentation, work by minimizing a given objective functional. The objective functional usually consists of a fidelity term and a regularization term. Because objective functionals may vary from different types of images, developing an efficient, simple, and general numerical method to minimize them has become increasingly vital. However, many existing methods are model-based, converge relatively slowly, or involve complicated techniques. In this paper, we develop a novel iterative convolution–thresholding method (ICTM) that is simple, efficient, and applicable to a wide range of variational models for image segmentation. In ICTM, the interface between two different segment domains is implicitly represented by the characteristic functions of domains. The fidelity term is usually written into a linear functional of the characteristic functions, and the regularization term is approximated by a functional of characteristic functions in terms of heat kernel convolution. This allows us to design an iterative convolution–thresholding method to minimize the approximate energy. The method has the energy-decaying property, and thus the unconditional stability is theoretically guaranteed. Numerical experiments show that the method is simple, easy to implement, robust, and applicable to various image segmentation models. Numéro de notice : A2022-779 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1016/j.patcog.2022.108794 Date de publication en ligne : 14/05/2022 En ligne : https://doi.org/10.1016/j.patcog.2022.108794 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101857 [article]

A search step optimization in an ambiguity function-based GNSS precise positioning / Sławomir Cellmer in Survey review, vol 54 n° 383 (March 2022)  

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Spatial patterns of living and dead small trees in subalpine Norway spruce forest reserves in Switzerland / Eva Bianchi in Forest ecology and management, vol 494 (August-15 2021)  

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Gravitational field modelling near irregularly shaped bodies using spherical harmonics: a case study for the asteroid (101955) Bennu / Blažej Bucha in Journal of geodesy, vol 95 n° 5 (May 2021)  

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A Voronoi-based method for land-use optimization using semidefinite programming and gradient descent algorithm / Vorapong Suppakitpaisarn in International journal of geographical information science IJGIS, vol 35 n° 5 (May 2021)  

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Automated street tree inventory using mobile LiDAR point clouds based on Hough transform and active contours / Amir Hossein Safaie in ISPRS Journal of photogrammetry and remote sensing, vol 174 (April 2021)  

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Spatial analysis of subway passenger traffic in Saint-Petersburg / Tatiana Baltyzhakova in Geodesy and cartography, vol 47 n° 1 (January 2021)  

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Probabilistic positioning in mobile phone network and its consequences for the privacy of mobility data / Aleksey Ogulenko in Computers, Environment and Urban Systems, vol 85 (January 2021)  

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A comparison of neighbourhood relations based on ordinary Delaunay diagrams and area Delaunay diagrams: an application to define the neighbourhood relations of buildings / Hiroyuki Usui in International journal of geographical information science IJGIS, vol 34 n° 11 (November 2020)  

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A framework for group converging pattern mining using spatiotemporal trajectories / Bin Zhao in Geoinformatica, vol 24 n° 4 (October 2020)  

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Vegetation unit assignments: phytosociology experts and classification programs show similar performance but low convergence / Lise Maciejewski in Applied Vegetation Science, vol 23 n° 4 (October 2020)  

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