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temps universel coordonnéSynonyme(s)UTC |
Documents disponibles dans cette catégorie (11)



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Effect of using different satellite ephemerides on GPS PPP and post processing techniques / Khaled Mahmoud Abdel Aziz in Geodesy and cartography, vol 47 n° 3 (October 2021)
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Titre : Effect of using different satellite ephemerides on GPS PPP and post processing techniques Type de document : Article/Communication Auteurs : Khaled Mahmoud Abdel Aziz, Auteur ; Loutfia Elsombaty, Auteur Année de publication : 2021 Article en page(s) : pp 104 - 110 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] Continuously Operating Reference Station network
[Termes IGN] éphémérides de satellite
[Termes IGN] erreur de positionnement
[Termes IGN] instrumentation Trimble
[Termes IGN] ligne de base
[Termes IGN] positionnement ponctuel précis
[Termes IGN] post-traitement GNSS
[Termes IGN] station de référence
[Termes IGN] temps universel coordonnéRésumé : (auteur) The orbital error is one of the errors in GPS which affect the accuracy of GPS positioning. In this research GPS broadcast, ultra-rapid, rapid and precise satellite ephemerides are used for processing different baseline lengths among some CORS stations by using the Trimble Business Center software (TBC) and different satellite ephemerides (NRCan ultra-rapid, NRCan rapid and IGS final) are tested in CSRS-PPP online application at the same CORS stations.In this research, when using TBC software for processing the different baseline lengths by using the different satellite eph-emerides and compared the coordinates of CORS stations which obtained from the different satellite ephemerides with each other. The results showed that the best satellite ephemerides closest to rapid and final satellite ephemerides are the ultra-rapid (00 UTC) and ultra-rapid (06 UTC). When processing the same CORS stations which used at TBC on CSRS-PPP online application by using the different satellite ephemerides it is found also that the NRCan ultra-rapid closest to final satellite ephemerides. Numéro de notice : A2021-862 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.3846/gac.2021.13762 Date de publication en ligne : 13/10/2021 En ligne : https://doi.org/10.3846/gac.2021.13762 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99078
in Geodesy and cartography > vol 47 n° 3 (October 2021) . - pp 104 - 110[article]Combinatorial optimization applied to VLBI scheduling / A. Corbin in Journal of geodesy, vol 94 n°2 (February 2020)
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Titre : Combinatorial optimization applied to VLBI scheduling Type de document : Article/Communication Auteurs : A. Corbin, Auteur ; B. Niedermann, Auteur ; Axel Nothnagel, Auteur ; et al., Auteur Année de publication : 2020 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse combinatoire (maths)
[Termes IGN] données VGOS
[Termes IGN] interférométrie à très grande base
[Termes IGN] positionnement par ITGB
[Termes IGN] programmation linéaire
[Termes IGN] retard troposphérique zénithal
[Termes IGN] station VLBI
[Termes IGN] téléscope
[Termes IGN] temps universel coordonnéRésumé : (auteur) Due to the advent of powerful solvers, today linear programming has seen many applications in production and routing. In this publication, we present mixed-integer linear programming as applied to scheduling geodetic very-long-baseline interferometry (VLBI) observations. The approach uses combinatorial optimization and formulates the scheduling task as a mixed-integer linear program. Within this new method, the schedule is considered as an entity containing all possible observations of an observing session at the same time, leading to a global optimum. In our example, the optimum is found by maximizing the sky coverage score. The sky coverage score is computed by a hierarchical partitioning of the local sky above each telescope into a number of cells. Each cell including at least one observation adds a certain gain to the score. The method is computationally expensive and this publication may be ahead of its time for large networks and large numbers of VLBI observations. However, considering that developments of solvers for combinatorial optimization are progressing rapidly and that computers increase in performance, the usefulness of this approach may come up again in some distant future. Nevertheless, readers may be prompted to look into these optimization methods already today seeing that they are available also in the geodetic literature. The validity of the concept and the applicability of the logic are demonstrated by evaluating test schedules for five 1-h, single-baseline Intensive VLBI sessions. Compared to schedules that were produced with the scheduling software sked, the number of observations per session is increased on average by three observations and the simulated precision of UT1-UTC is improved in four out of five cases (6 μs average improvement in quadrature). Moreover, a simplified and thus much faster version of the mixed-integer linear program has been developed for modern VLBI Global Observing System telescopes. Numéro de notice : A2020-153 Affiliation des auteurs : non IGN Thématique : MATHEMATIQUE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-020-01348-w Date de publication en ligne : 29/01/2020 En ligne : https://doi.org/10.1007/s00190-020-01348-w Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94786
in Journal of geodesy > vol 94 n°2 (February 2020)[article]
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Titre : The clock at the center of the universe Type de document : Article/Communication Auteurs : Gavin Schrock, Auteur Année de publication : 2015 Article en page(s) : pp 31 - 35 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie
[Termes IGN] chronométrie
[Termes IGN] Global Positioning System
[Termes IGN] horloge atomique
[Termes IGN] temps universel coordonnéRésumé : (éditeur) To provide precise global time that's critical to our digital world, the United States Naval Observatory serves as the major node in a world-wide array of synchronized atomic clocks Numéro de notice : A2015-955 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT/SOCIETE NUMERIQUE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79848
in xyHt > vol 2015 n° 6 (June 2015) . - pp 31 - 35[article]
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Titre : IOV passes with flying colors Type de document : Article/Communication Auteurs : Marco Falcone, Auteur Année de publication : 2013 Article en page(s) : pp 36 - 37 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] constellation Galileo
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] positionnement par Galileo
[Termes IGN] positionnement par GNSS
[Termes IGN] signal Galileo
[Termes IGN] temps universel coordonnéRésumé : (Documentaliste) Après les lancements de satellites et la mise en oeuvre de différentes opérations attendues durant 2013, la compatibilité du système de positionnement Galileo avec les systèmes GPS et GLONASS va maintenant être testée. Numéro de notice : A2013-647 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32783
in GPS world > vol 24 n° 12 (December 2013) . - pp 36 - 37[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 067-2013121 RAB Revue Centre de documentation En réserve 3L Disponible Geolocation and time: an evolution of the millenial pair, Part 2 / J. Triglav in Geoinformatics, vol 12 n° 8 (01/12/2009)
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Titre : Geolocation and time: an evolution of the millenial pair, Part 2 Type de document : Article/Communication Auteurs : J. Triglav, Auteur Année de publication : 2009 Article en page(s) : pp 36 - 41 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] géodésie spatiale
[Termes IGN] Global Navigation Satellite System
[Termes IGN] navigation
[Termes IGN] positionnement par géodésie spatiale
[Termes IGN] système de référence mondial
[Termes IGN] temps universel coordonnéRésumé : (Auteur) This is the second and last part of the article that was printed in the previous issue of GeoInformatics (issue nr 7, october/november 2009). Part 1 was about a short history of relations between Geolocation and Time, describing the following topics : The shape and the size of Earth, latitude, longitude and time, from the spherical and ellipsoidal Earth, transition to the geoid and the third dimension in geodesy. Part 2 continue with the fourth dimension in geodesy and describes shortly the main topics of geodesy and its scientific field in the beginning of 21st century, which are the cornerstones that allow modern geodesy to provide globally the best possible service to the various daily life fields of work and living of an individual and to the society as a whole. Copyright GEOinformatics Numéro de notice : A2009-446 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30077
in Geoinformatics > vol 12 n° 8 (01/12/2009) . - pp 36 - 41[article]Voir aussiRéservation
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Code-barres Cote Support Localisation Section Disponibilité 262-09081 SL Revue Centre de documentation Revues en salle Disponible Practical satellite navigation: part 2 GPS position and time determination / Huibert-Jan Lekkerkerk in Geoinformatics, vol 9 n° 2 (01/03/2006)
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