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Enhancing cadastral surveys by facilitating the participation of owners / G. Mourafetis in Survey review, vol 47 n° 344 (September 2015)  

Public [article]  inSurvey review > vol 47 n° 344 (September 2015) . - pp 316 - 324 Titre : Enhancing cadastral surveys by facilitating the participation of owners Type de document : Article/Communication Auteurs : G. Mourafetis, Auteur ; K. Apostolopoulos, Auteur ; Chryssy Potsiou, Auteur ; C. Ioannidis, Auteur Année de publication : 2015 Conférence : FIG 2014, Commission 3 Annual Workshop, Geospatial Crowdsourcing and VGI: Establishment of SDI & SIM 04/11/2014 07/11/2014 Bologne Italie Article en page(s) : pp 316 - 324 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cadastre étranger [Termes IGN] acquisition de données [Termes IGN] approche participative [Termes IGN] base de données foncières [Termes IGN] données localisées des bénévoles [Termes IGN] Grèce [Termes IGN] mise à jour de base de données [Termes IGN] orthoimage [Termes IGN] production participative Résumé : (auteur) While some countries have over centuries developed a nation-wide spatial framework, some others have been left behind. However, because of the global economic and social challenges, there is an urgent need for those countries to develop similar systems in a fast and efficient way for their economic survival. Building such a framework should be always based on each country's resources and capacities. In systematic cadastral registrations, the participation of owners has always been crucial for the success of the project. Within this concept, the authors investigate the potential of new tools to increase the participation of land right holders and local volunteers (non-professionals) and to enhance the cadastral surveying procedure. A hybrid “crowdsourcing” approach is proposed, mainly based on the direct participation of property rights holders in which the role of the cadastral surveyor is crucial. A commercial application for smartphones is tested. The smartphone's GPS is used only for the general positioning on the basemap to avoid gross errors when owners are not accustomed in using aerial photos. A recent orthoimage of 20 cm pixel size in urban areas and an orthoimage basemap of 50 cm pixel size in rural areas is used as the basemap. Once roughly positioned, owners may then digitise the boundary coordinates on the basemap off-line, with little training support; they may also work from a distance. In areas where the property boundaries are easily recognised on the basemap, boundary coordinates have the expected geometric accuracy that can be achieved on the basemap while no gross errors are detected. Attachment of photos is also possible (e.g. photos of the property or of the deeds). Restricted access to personal data may also be achieved. The method is also useful for cadastre updating purposes (e.g. the periodic updating of buildings database). Numéro de notice : A2015-915 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1179/1752270615Y.0000000009 En ligne : https://doi.org/10.1179/1752270615Y.0000000009 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79703 [article]

Towards the production of digital terrain models from volunteered GPS trajectories / I. Massad in Survey review, vol 47 n° 344 (September 2015)  

Public [article]  inSurvey review > vol 47 n° 344 (September 2015) . - pp 325 - 332 Titre : Towards the production of digital terrain models from volunteered GPS trajectories Type de document : Article/Communication Auteurs : I. Massad, Auteur ; Sagi Dalyot, Auteur Année de publication : 2015 Conférence : FIG 2014, Commission 3 Annual Workshop, Geospatial Crowdsourcing and VGI: Establishment of SDI & SIM 04/11/2014 07/11/2014 Bologne Italie Article en page(s) : pp 325 - 332 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes IGN] données localisées 2D [Termes IGN] données localisées des bénévoles [Termes IGN] modèle numérique de terrain [Termes IGN] OpenStreetMap [Termes IGN] positionnement par GPS [Termes IGN] précision des données [Termes IGN] production participative [Termes IGN] qualité des données [Termes IGN] web mapping [Termes IGN] Wikimapia Résumé : (auteur) There currently exists a wide variety of online resources providing mapping infrastructures and geographic information. Most web-based map services, such as Google Maps, Yahoo! Maps and Bing Maps, are mostly based on data that is collected by authoritative mapping agencies. Alternatively, some relatively new web-map services, such as OpenStreetMap (OSM) and Wikimapia, are mostly based on volunteered data collected by the public (e.g. crowdsourced mapping). Although such volunteered-based map services platforms show an increasing planimetric (2D) accuracy, completeness and update-rate of their mapping infrastructure, surprisingly enough, there is a lack of comparable data and accuracy measures in respect to the third dimension, i.e. height; more specifically, the topographic representation that is based on the volunteered collected data. Most of these web services still rely on existing open-source authoritative topographic infrastructures, and not on data collected by the volunteers. Moreover, topographic information that is open to the public and is free to use, e.g. advanced spaceborne thermal emission and reflection radiometer and shuttle radar topography mission, is regularly available with relatively low height accuracy (not better than 5 m) and low planimetric resolution (over 30 m). Volunteered data, on the other hand, collected by individuals that are situated ‘all over’ the globe can offer with new capabilities and data characteristics having potentially higher qualities. This research proposes to examine the feasibility of using crowdsourced volunteered geographic information working paradigm for the task of producing a reliable digital terrain model (DTM) infrastructure for general use. This is achieved by collecting GPS observations that are available from VG data sources, while applying a 2D Kalman filter-based algorithm, aimed at reducing noise and ambiguities. This paper presents this methodology, with preliminary analysis results achieved by this implementation, showing the feasibility of this working methodology, having good results and accuracy of the DTM generated. Numéro de notice : A2015-916 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1179/1752270615Y.0000000010 En ligne : https://doi.org/10.1179/1752270615Y.0000000010 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79704 [article]

OpenStreetMap for cadastral purposes: an application using VGI for official processes in urban areas / S. Basiouka in Survey review, vol 47 n° 344 (September 2015)  

Public [article]  inSurvey review > vol 47 n° 344 (September 2015) . - pp 333 - 341 Titre : OpenStreetMap for cadastral purposes: an application using VGI for official processes in urban areas Type de document : Article/Communication Auteurs : S. Basiouka, Auteur ; Chryssy Potsiou, Auteur ; Efthimios Bakogiannis, Auteur Année de publication : 2015 Article en page(s) : pp 333 - 341 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cadastre étranger [Termes IGN] Athènes [Termes IGN] données localisées des bénévoles [Termes IGN] Grèce [Termes IGN] lever cadastral [Termes IGN] OpenStreetMap [Termes IGN] spécification de contenu [Termes IGN] web mapping Résumé : (auteur) The scope of the paper is to test if the online dynamic maps such as the OpenStreetMap (OSM) can be used for official mapping projects such as Cadastre, to investigate the advantages and the concerns of online and open to the public procedures and to identify those differentiations between experts and amateurs that play a critical role in such official projects. The specific research is focused on the use of OSM in urban areas as an alternative method to the official cadastral surveys. This paper presents the possibilities and the perspectives of OSM for spatial and attribute cadastral data collection and storage for the compilation of draft cadastral maps as an alternative methodology within the terms of the volunteered geographic information (VGI). The authors carried out a practical experiment in an extended part of the historic city centre of Athens and updated the online dynamic map of OSM with attribute and spatial cadastral data. Surveying students explored the capacities of the dynamic map in two steps: (a) in a section where the polygons of the buildings already existed on the map, they had to improve it with attribute data, and (b) in another section where no relevant polygons existed, a spatial and attribute data enhancement was required. The research was based on the various approaches that each student adopted and the freedom that the OSM offers to the users. The results show that users can easily distinguish the differences in capacities between the OSM and the commercial software; the inexpensive, easy to use and quick methodology of the OSM in contrast to the accurate, authoritative and assured methodology of the commercial software. Numéro de notice : A2015-917 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1179/1752270615Y.0000000011 En ligne : https://doi.org/10.1179/1752270615Y.0000000011 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79708 [article]

Quantitative evaluation of volunteered geographic information paradigms: social location-based services case study / B. Lipej in Survey review, vol 47 n° 344 (September 2015)  

Public [article]  inSurvey review > vol 47 n° 344 (September 2015) . - pp 342-348 Titre : Quantitative evaluation of volunteered geographic information paradigms: social location-based services case study Type de document : Article/Communication Auteurs : B. Lipej, Auteur ; J. Male, Auteur Année de publication : 2015 Article en page(s) : pp 342-348 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Infrastructure de données [Termes IGN] Albanie [Termes IGN] données localisées des bénévoles [Termes IGN] forêt communale [Termes IGN] infrastructure nationale des données localisées [Termes IGN] paturage [Termes IGN] production participative [Termes IGN] sylviculture [Termes IGN] Union Européenne Résumé : (auteur) In many countries, the trend of building and maintaining efficient land administration systems has expanded rapidly over the past decades. There has also been growing awareness and development of spatial data infrastructures, the sustainable management of natural resources and preservation of the environment because of the realisation that these are all vital to socioeconomic progress around the world. The number of participatory mapping initiatives is quickly increasing in many parts of the world. Participatory mapping has emerged as a process and a powerful tool, utilising visual techniques to better understand local natural resources, together with their management, dynamics and related challenges, and with potential solutions to the challenges. It is a relatively fast way of gaining information from those who live with and use these resources. Although there are differences among the initiatives in their methods, applications and users, the common theme linking them is that the process of map-making is undertaken by a group of non-experts who are associated with each other based on a shared interest. Decisions about resource tenure are some of the most critical ones for forests and livelihoods in many contexts, and secure tenure arrangements are an important prerequisite for achieving sustainable forest management. Hereinafter a general overview of the current status of land administration in Albania is presented, with an emphasis on the modern development and changing priorities of the national registration institution and the government. The more innovative part of the paper deals with the participatory mapping initiative of communal forests and pasture use rights in Albania, the experiences gained and the suggested path ahead. Experience with participatory mapping in land registration combined with the forestry management in Europe is relatively rare when compared to other parts of the world. Numéro de notice : A2015-918 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1179/1752270615Y.0000000013 En ligne : https://doi.org/10.1179/1752270615Y.0000000013 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79709 [article]

New data processing strategy for single frequency GPS deformation monitoring / S-Q. Huang in Survey review, vol 47 n° 344 (September 2015)  

Public [article]  inSurvey review > vol 47 n° 344 (September 2015) . - pp 379 - 385 Titre : New data processing strategy for single frequency GPS deformation monitoring Type de document : Article/Communication Auteurs : S-Q. Huang, Auteur ; J-X. Wang, Auteur Année de publication : 2015 Article en page(s) : pp 379 - 385 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] ligne de base [Termes IGN] récepteur monofréquence [Termes IGN] réseau de surveillance géophysique [Termes IGN] retard ionosphèrique [Termes IGN] surveillance [Vedettes matières IGN] Traitement de données GNSS Résumé : (auteur) Although the application of the single frequency receiver in GPS deformation monitoring is limited mainly by the effect of the ionospheric delays, the relevant studies have never been stopped due to the much cheaper price of the single frequency receivers. In this paper, we introduce a new data processing strategy for the deformation monitoring network where the baselines between any two nearest stations are processed instead of the baselines formed only between the reference stations and monitoring stations in the traditional strategy. As a result, most of the baselines in the monitoring networks are very short so as to the ionospheric effects can be safely ignored. The results from the experiments show that the new strategy can eliminate the effect of ionospheric delay by processing the short baselines in the network mode. The accuracy and integrity of the deformation solutions can be improved by the presented strategy. Numéro de notice : A2015-919 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270614Y.0000000138 En ligne : https://doi.org/10.1179/1752270614Y.0000000138 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79710 [article]