Descripteur
Documents disponibles dans cette catégorie (436)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
Accuracy assessment of RTK-GNSS equipped UAV conducted as-built surveys for construction site modelling / Sander Varbla in Survey review, Vol 53 n° 381 (November 2021)
[article]
Titre : Accuracy assessment of RTK-GNSS equipped UAV conducted as-built surveys for construction site modelling Type de document : Article/Communication Auteurs : Sander Varbla, Auteur ; Raido Puust, Auteur ; Artu Ellmann, Auteur Année de publication : 2021 Article en page(s) : pp 477 - 492 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] données localisées 3D
[Termes IGN] géoréférencement direct
[Termes IGN] image captée par drone
[Termes IGN] modèle 3D de l'espace urbain
[Termes IGN] modélisation 3D du bâti BIM
[Termes IGN] photogrammétrie aérienne
[Termes IGN] point d'appui
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] précision centimétrique
[Termes IGN] structure-from-motionRésumé : (Auteur) Regular as-built surveys have become a necessary input for building information modelling. Such large-scale 3D data capturing can be conducted effectively by combining structure-from-motion and unmanned aerial vehicles (UAV). Using a RTK-GNSS equipped UAV, 22 repeated weekly campaigns were conducted at two altitudes in various conditions. The photogrammetric approach yielded 3D models, which were compared to the terrestrial laser scanning based ground truth. Better than 2.8 cm geometry RMSE was consistently achieved using integrated georeferencing. It is concluded that the RTK-GNSS based georeferencing enables reaching better than 5 cm geometry accuracy by utilising at least one ground control point. Numéro de notice : A2021-912 Affiliation des auteurs : non IGN Thématique : IMAGERIE/URBANISME Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2020.1830544 Date de publication en ligne : 15/10/2020 En ligne : https://doi.org/10.1080/00396265.2020.1830544 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99310
in Survey review > Vol 53 n° 381 (November 2021) . - pp 477 - 492[article]Determination of the orthometric height difference based on optical fiber frequency transfer technique / Anh The Hoang in Geodesy and Geodynamics, vol 12 n° 6 (November 2021)
[article]
Titre : Determination of the orthometric height difference based on optical fiber frequency transfer technique Type de document : Article/Communication Auteurs : Anh The Hoang, Auteur ; Ziyu Shen, Auteur ; Wenbin Shen, Auteur Année de publication : 2021 Article en page(s) : pp 405 - 412 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie
[Termes IGN] altimétrie
[Termes IGN] altitude orthométrique
[Termes IGN] coefficient de géopotentiel
[Termes IGN] fibre optique
[Termes IGN] fréquence
[Termes IGN] précision centimétriqueMots-clés libres : optical fiber frequency transfer Résumé : (auteur) The development of remote frequency transfer techniques, especially the appearance of optical clocks with unprecedented stability, has prompted geoscientists to study their applications in geodesy. Using remote frequency transfer technique, by frequency comparison of two optical clocks at two points P and Q connected by optical fibers, one can measure the signal's frequency shift between them, and the geopotential difference between them can be determined based on the gravity frequency shift equation. Given the orthometric height of P, the orthometric height of Q can be determined. Since the present stability of the optical clock has achieved 1 × 10−18 or better and comparing the frequency transfer via optical fiber provides stability at 10−19 level, the optical clock network enables determining the orthometric height at centimeter-level. This study provides a formulation to determine the height difference at one-centimeter level between two points on the ground based on the optical fiber frequency transfer technique. Numéro de notice : A2021-945 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1016/j.geog.2021.08.003 Date de publication en ligne : 22/09/2021 En ligne : https://doi.org/10.1016/j.geog.2021.08.003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99757
in Geodesy and Geodynamics > vol 12 n° 6 (November 2021) . - pp 405 - 412[article]4 807,81 m, le sommet décline / Anonyme in Géomètre, n° 2195 (octobre 2021)
[article]
Titre : 4 807,81 m, le sommet décline Type de document : Article/Communication Auteurs : Anonyme, Auteur Année de publication : 2021 Article en page(s) : pp 8-11 Langues : Français (fre) Descripteur : [Vedettes matières IGN] Nivellement
[Termes IGN] calotte glaciaire
[Termes IGN] campagne d'observations
[Termes IGN] Mont-Blanc, massif du
[Termes IGN] positionnement par géodésie spatiale
[Termes IGN] précipitation
[Termes IGN] précision centimétrique
[Termes IGN] ventRésumé : (Auteur) Retour aux manuels scolaires... La onzième campagne de mesures du Mont-Blanc par les géomètres-experts confirme ses 4 807,81 m d'altitude. Avec cependant des variations permanentes. Numéro de notice : A2021-674 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtSansCL DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98851
in Géomètre > n° 2195 (octobre 2021) . - pp 8-11[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 063-2021091 RAB Revue Centre de documentation En réserve L003 Disponible On determination of the geoid from measured gradients of the Earth's gravity field potential / Pavel Novák in Earth-Science Reviews, vol 221 (October 2021)
[article]
Titre : On determination of the geoid from measured gradients of the Earth's gravity field potential Type de document : Article/Communication Auteurs : Pavel Novák, Auteur ; Michal Šprlák, Auteur ; Martin Pitoňák, Auteur Année de publication : 2021 Article en page(s) : n° 103773 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] géoïde terrestre
[Termes IGN] gradient de gravitation
[Termes IGN] modèle mathématique
[Termes IGN] modèle stochastique
[Termes IGN] précision centimétrique
[Termes IGN] problème des valeurs limitesRésumé : (auteur) The geoid is an equipotential surface of the static Earth's gravity field which plays a fundamental role in definition of physical heights related to the mean sea level (orthometric heights) in geodesy and which represents a reference surface in many geoscientific studies. Its determination with the cm-level accuracy or better, in particular over dry land, belongs to major tasks of modern geodesy. Traditional data and underlined theory have significantly been affected in recent years by rapid advances in observation techniques. This study reviews gradients of the disturbing gravity potential, both currently available and foreseen, and systematically discusses mathematical models for geoid determination based on gradient data. Fundamentals required for geoid definition and its estimation from measured potential gradients are shortly reviewed at the beginning of the text. Then particular mathematical models based on solutions to boundary-value problems of the potential theory, which include both integral transforms and integral equations, are formulated. Properties of respective integral kernel functions are demonstrated and discussed. With the new mathematical models introduced, new research topics are opened which must be resolved in order to allow for their full-fledged applicability in geoid modelling. Stochastic modelling is also discussed which estimates gradient spatial resolution and accuracy required for geoid modelling with the cm-level accuracy. Results of stochastic modelling suggest that the cm-geoid can be estimated using available gradient data if related problems, namely reduction of gradient data for gravitational effects of all masses outside the geoid and their downward continuation, are solved at the same level of accuracy. Numéro de notice : A2021-944 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1016/j.earscirev.2021.103773 Date de publication en ligne : 14/09/2021 En ligne : https://doi.org/10.1016/j.earscirev.2021.103773 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99756
in Earth-Science Reviews > vol 221 (October 2021) . - n° 103773[article]The integration of GPS/BDS real-time kinematic positioning and visual–inertial odometry based on smartphones / Zun Niu in ISPRS International journal of geo-information, vol 10 n° 10 (October 2021)
[article]
Titre : The integration of GPS/BDS real-time kinematic positioning and visual–inertial odometry based on smartphones Type de document : Article/Communication Auteurs : Zun Niu, Auteur ; Fugui Guo, Auteur ; Qiangqiang Shuai, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 699 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] C++
[Termes IGN] centrale inertielle
[Termes IGN] filtre de Kalman
[Termes IGN] format RINEX
[Termes IGN] odomètre
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] positionnement par BeiDou
[Termes IGN] positionnement par GNSS
[Termes IGN] précision du positionnement
[Termes IGN] programmation informatique
[Termes IGN] robot
[Termes IGN] téléphone intelligent
[Termes IGN] vision par ordinateurRésumé : (auteur) The real-time kinematic positioning technique (RTK) and visual–inertial odometry (VIO) are both promising positioning technologies. However, RTK degrades in GNSS-hostile areas, where global navigation satellite system (GNSS) signals are reflected and blocked, while VIO is affected by long-term drift. The integration of RTK and VIO can improve the accuracy and robustness of positioning. In recent years, smartphones equipped with multiple sensors have become commodities and can provide measurements for integrating RTK and VIO. This paper verifies the feasibility of integrating RTK and VIO using smartphones, and we propose an improved algorithm to integrate RTK and VIO with better performance. We began by developing an Android smartphone application for data collection and then wrote a Python program to convert the data to a robot operating system (ROS) bag. Next, we established two ROS nodes to calculate the RTK results and accomplish the integration. Finally, we conducted experiments in urban areas to assess the integration of RTK and VIO based on smartphones. The results demonstrate that the integration improves the accuracy and robustness of positioning and that our improved algorithm reduces altitude deviation. Our work can aid navigation and positioning research, which is the reason why we open source the majority of the codes at our GitHub. Numéro de notice : A2021-800 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/ijgi10100699 Date de publication en ligne : 14/10/2021 En ligne : https://doi.org/10.3390/ijgi10100699 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98852
in ISPRS International journal of geo-information > vol 10 n° 10 (October 2021) . - n° 699[article]Impact of different sampling rates on precise point positioning performance using online processing service / Serdar Erol in Geo-spatial Information Science, vol 24 n° 2 (June 2021)PermalinkPléiades Neo, 4 satellites réactifs / Laurent Polidori in Géomètre, n° 2191 (mai 2021)PermalinkSRP, une base de calage 3D de très haute précision sur le continent africain / Laure Chandelier in Revue Française de Photogrammétrie et de Télédétection, n° 223 (mars - décembre 2021)PermalinkModélisation des délais ionosphériques appliquée au traitement PPP-RTK centimétrique avec ambiguïtés entières de phase / Camille Parra in XYZ, n° 166 (mars 2021)PermalinkRadar measurements of snow depth over sea ice on an unmanned aerial vehicle / Adrian Eng-Choon Tan in IEEE Transactions on geoscience and remote sensing, Vol 59 n° 3 (March 2021)PermalinkThe Realization and evaluation of PPP ambiguity resolution with INS aiding in marine survey / Zhenqiang Du in Marine geodesy, vol 44 n° 2 (March 2021)PermalinkA practical method for calculating reliable integer float estimator in GNSS precise positioning / Xianwen Yu in Survey review, Vol 53 n° 377 (February 2021)PermalinkApplication of baseline constraint Kalman filter to BeiDou precise point positioning / Xiaoguo Guan in Survey review, vol 53 n°376 (January 2021)PermalinkEvaluation of multipath mitigation performance using signal-to-noise ratio (SNR) based signal selection methods / Valanon Uaratanawong in Journal of applied geodesy, vol 15 n° 1 (January 2021)PermalinkExpérience professionnelle en bureau d'étude / Hugo Cornille (2021)Permalink