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Auteur Guenther Retscher |
Documents disponibles écrits par cet auteur (10)
Ajouter le résultat dans votre panier Affiner la recherche Interroger des sources externesUrban Wi-Fi fingerprinting along a public transport route / Guenther Retscher in Journal of applied geodesy, vol 14 n° 4 (October 2020)
Titre : Urban Wi-Fi fingerprinting along a public transport route Type de document : Article/Communication Auteurs : Guenther Retscher, Auteur ; Aizhan Bekenova, Auteur Année de publication : 2020 Article en page(s) : pp 379 – 392 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] accès sans fils à l'internet
[Termes IGN] cartographie et localisation simultanées
[Termes IGN] centrale inertielle
[Termes IGN] empreinte
[Termes IGN] itinéraire
[Termes IGN] migration pendulaire
[Termes IGN] positionnement par WiFi
[Termes IGN] programmation par contraintes
[Termes IGN] qualité du signal
[Termes IGN] service fondé sur la position
[Termes IGN] téléphone intelligent
[Termes IGN] transport collectif
[Termes IGN] zone urbaineRésumé : (auteur) The outreach of Wi-Fi localization is extended in this study for urban wide applications as they provide the high potential to employ them for numerous applications for localization and guidance in urban environments. The selected application presented in this paper is the localization and routing of public transport smartphone users. For the conducted investigations, Received Signal Strength Indicator (RSSI) values are collected for users who are travelling from home in a residential neighbourhood to work in the city centre and return along the same route. Special tramway trains are selected which provide two on-board Wi-Fi Access Points (APs). Firstly, the availability, visibility and RSSI stability of the Wi-Fi signal behavior of these APs and the APs in the surrounding environment along the routes is analyzed. Then the trajectories are estimated based on location fingerprinting. A first analyses reveals that significant differences exists between the six employed smartphones as well as times of the day, e. g. in the morning at peak hours or at off-peak hours. From the long-time observations it is seen that the two on-board APs show a high stability of the RSSI signals at the same times of the day and along the whole route. It is therefore currently investigated how they can confirm and validate user localization along the route and if they can contribute to constrain the overall positioning solution in combination with the inertial smartphone sensors. Moreover, the railway track can serve as a further constraint. As an outlook on future work, the development of a Simultaneous Localization and Mapping (SLAM) solution with a fusion with the smartphone inertial sensors is proposed. Numéro de notice : A2020-676 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT/URBANISME Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1515/jag-2020-0015 Date de publication en ligne : 16/07/2020 En ligne : https://doi.org/10.1515/jag-2020-0015 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96168
in Journal of applied geodesy > vol 14 n° 4 (October 2020) . - pp 379 – 392[article]
Titre : Trilateration approaches for seamless out-/indoor GNSS and Wi-Fi smartphone positioning Type de document : Article/Communication Auteurs : Guenther Retscher, Auteur ; Jonathan Kleine, Auteur ; Lisa Whitemore, Auteur Année de publication : 2019 Article en page(s) : pp 47 - 61 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] géolocalisation
[Termes IGN] positionnement en intérieur
[Termes IGN] positionnement par WiFi
[Termes IGN] téléphone intelligent
[Termes IGN] test de performance
[Termes IGN] trilatérationRésumé : (Auteur) More and more sensors and receivers are found nowadays in smartphones which can enable and improve positioning for Location-based Services and other navigation applications. Apart from inertial sensors, such as accelerometers, gyroscope and magnetometer, receivers for Wireless Fidelity (Wi-Fi) and GNSS signals can be employed for positioning of a mobile user. In this study, three trilateration methods for Wi-Fi positioning are investigated whereby the influence of the derivation of the relationship between the received signal strength (RSS) and the range to an Access Points (AP) are analyzed. The first approach is a straightforward resection for point determination and the second is based on the calculation of the center of gravity in a triangle of APs while weighting the received RSS. In the third method a differential approach is employed where as in Differential GNSS (DGNSS) corrections are derived and applied to the raw RSS measurements. In this Differential Wi-Fi (DWi-Fi) method, reference stations realized by low-cost Raspberry Pi units are used to model temporal RSS variations. In the experiments in this study two different indoor environments are used, one in a laboratory and the second in the entrance of an office building. The results of the second and third approach show position deviations from the ground truth of around 2 m in dependence of the geometrical point location. Furthermore, the transition between GNSS positioning outdoors and Wi-Fi localization indoors in the entrance area of the building is studied. Numéro de notice : A2019-134 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1515/jag-2018-0022 Date de publication en ligne : 19/10/2018 En ligne : https://doi.org/10.1515/jag-2018-0022 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92464
in Journal of applied geodesy > vol 13 n° 1 (January 2019) . - pp 47 - 61[article]
Titre : vol 12 n° 1 - January 2018 Type de document : Périodique Auteurs : Hans Neuner, Éditeur scientifique ; Guenther Retscher, Éditeur scientifique ; Heribert Kahmen, Éditeur scientifique ; Chris Rizos, Éditeur scientifique Année de publication : 2018 Langues : Français (fre) Numéro de notice : sans Affiliation des auteurs : non IGN Nature : Numéro de périodique En ligne : https://www.degruyter.com/view/j/jag.2018.12.issue-1/issue-files/jag.2018.12.iss [...] Format de la ressource électronique : URL bulletin Permalink : https://documentation.ensg.eu/index.php?lvl=bulletin_display&id=30851 [n° ou bulletin]
- Assessing the quality of GEOID12B model through field surveys / Ahmed F. Elaksher in Journal of applied geodesy, vol 12 n° 1 (January 2018)
- Applying the GOCE-based GGMs for the quasi-geoid modelling of Finland / Timo Saari in Journal of applied geodesy, vol 12 n° 1 (January 2018)
- An accurate Kriging-based regional ionospheric model using combined GPS/BeiDou observations / Mohamed Abdelazeem in Journal of applied geodesy, vol 12 n° 1 (January 2018)
- Testing deformation hypotheses by constraints on a time series of geodetic observations / Hiddo Velsink in Journal of applied geodesy, vol 12 n° 1 (January 2018)
Titre : vol 11 n° 4 - December 2017 Type de document : Périodique Auteurs : Hans Neuner, Éditeur scientifique ; Guenther Retscher, Éditeur scientifique ; Heribert Kahmen, Éditeur scientifique ; Chris Rizos, Éditeur scientifique Année de publication : 2017 Langues : Français (fre) Numéro de notice : sans Affiliation des auteurs : non IGN Nature : Numéro de périodique En ligne : https://www.degruyter.com/view/j/jag.2017.11.issue-4/issue-files/jag.2017.11.iss [...] Format de la ressource électronique : URL bulletin Permalink : https://documentation.ensg.eu/index.php?lvl=bulletin_display&id=30850 [n° ou bulletin]
- Indoor positioning using differential Wi-Fi lateration / Guenther Retscher in Journal of applied geodesy, vol 11 n° 4 (December 2017)
- Congruence analysis of geodetic networks, hypothesis tests versus model selection by information criteria / Rüdiger Lehmann in Journal of applied geodesy, vol 11 n° 4 (December 2017)
Titre : Indoor positioning using differential Wi-Fi lateration Type de document : Article/Communication Auteurs : Guenther Retscher, Auteur ; Thomas Tatschl, Auteur Année de publication : 2017 Article en page(s) : pp 249 - 269 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] appareil portable
[Termes IGN] multilatération
[Termes IGN] positionnement en intérieur
[Termes IGN] positionnement par WiFiRésumé : (Auteur) For Wi-Fi positioning usually location fingerprinting or (tri)lateration are employed whereby the received signal strengths (RSSs) of the surrounding Wi-Fi Access Points (APs) are scanned on the mobile devices and used to perform localization. Within the scope of this study, the position of a mobile user is determined on the basis of lateration. Two new differential approaches are developed and compared to two common models, i.e., the one-slope and multi-wall model, for the conversion of the measured RSS of the Wi-Fi signals into ranges. The two novel methods are termed DWi-Fi as they are derived either from the well-known DGPS or VLBI positioning principles. They make use of a network of reference stations deployed in the area of interest. From continuous RSS observations on these reference stations correction parameters are derived and applied by the user in real-time. This approach leads to a reduced influence of temporal and spatial variations and various propagation effects on the positioning result. In practical use cases conducted in a multi-storey office building with three different smartphones, it is proven that the two DWi-Fi approaches outperform the common models as static positioning yielded to position errors of about 5 m in average under good spatial conditions. Numéro de notice : A2017-791 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2017-0011 En ligne : https://doi.org/10.1515/jag-2017-0011 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89063
in Journal of applied geodesy > vol 11 n° 4 (December 2017) . - pp 249 - 269[article]vol 11 n° 2 - June 2017 - Deformation Monitoring (Bulletin de Journal of applied geodesy) / Hans Neuner
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