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Future time : opportunities for using optical clocks in GNSS systems / A. Moudrak in Inside GNSS, vol 3 n° 6 (September 2008) 

Public [article]  inInside GNSS > vol 3 n° 6 (September 2008) . - 6 p. ; pp 45 - 50 Titre : Future time : opportunities for using optical clocks in GNSS systems Type de document : Article/Communication Auteurs : A. Moudrak, Auteur ; H. Klein, Auteur ; Bernd Eissfeller, Auteur Année de publication : 2008 Article en page(s) : 6 p. ; pp 45 - 50 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] Global Navigation Satellite System [Termes IGN] horloge [Termes IGN] secteur spatial Résumé : (Auteur) Satellite clock prediction accuracy may be considerably improved with the emerging optical clock technology. To maximize the performance benefits, optical clocks should be placed onboard the satellites (and on ground to generate the system time). Implementation of optical clocks to keep the system time could increase the accuracy of Galileo timing service (dissemination of UTC) and keep the UTC prediction function within the system. In this case, dependence on an external infrastructure such as the TSP may be reduced. If other contributions to the error budget (mainly, the multipath) were reduced, we might anticipate further significant benefits to user positioning accuracy from improved clock technology, for instance, through exploitation of carrier phase techniques. Placing better clocks on satellites will reduce the need for frequent updates, which will simplify the requirements on ground systems and also reduce costs. If update links were to fail for a significant amount of time, having very good clocks in the space segment would reduce the rate of degradation of the service to users on the ground. Copyright Gibbons Media & Research LLC Numéro de notice : A2008-678 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33531 [article]

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GNSS development / A. Moudrak in Geoinformatics, vol 10 n° 1 (01/01/2007)

Public [article]  inGeoinformatics > vol 10 n° 1 (01/01/2007) . - pp 54 - 59 Titre : GNSS development Type de document : Article/Communication Auteurs : A. Moudrak, Auteur ; A. Konovaltsev, Auteur ; et al., Auteur Année de publication : 2007 Article en page(s) : pp 54 - 59 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] constellation Galileo [Termes IGN] Galileo [Termes IGN] Global Navigation Satellite System [Termes IGN] Global Orbitography Navigation Satellite System [Termes IGN] Global Positioning System [Termes IGN] GSM [Termes IGN] interopérabilité [Termes IGN] navigation automobile [Termes IGN] navigation pédestre [Termes IGN] positionnement par géodésie spatiale Résumé : (Auteur) Precise positioning and timing services have evolved considerably over the past decades. They now represent a vital part of the modern information infrastructure and are entering everyday life. This fantastic growth has been made possible by GNSS (Global Navigation Satellite System). These systems are widely used, not only in professional applications but also, by enabling personal navigation (e.g. car navigation or hand-held GPS navigators), in the mass market. Futhermore, a number of key communication technologies like GSM (Global System for Mobile Communications) mobile networks rely on timing information provided by GNSS. At present there two GNSS : the US Global Positioning Sytem (GPS) and the Russian GLONASS (GLObal NAvigation Satellite System). Copyright GEOinformatics Numéro de notice : A2007-076 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28441 [article]

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262-07011	SL	Revue	Centre de documentation	Revues en salle	Disponible

Interoperability on time: GPS-Galileo offset will bias position / A. Moudrak in GPS world, vol 16 n° 3 (March 2005)

Public [article]  inGPS world > vol 16 n° 3 (March 2005) . - pp 24 - 32 Titre : Interoperability on time: GPS-Galileo offset will bias position Type de document : Article/Communication Auteurs : A. Moudrak, Auteur ; et al., Auteur Année de publication : 2005 Article en page(s) : pp 24 - 32 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] erreur systématique [Termes IGN] étalonnage d'instrument [Termes IGN] interopérabilité [Termes IGN] récepteur GPS [Termes IGN] temps atomique international Résumé : (Auteur) The offset between GPS and Galileo system timescales will cause a bias between GPS and Galileo measurements in combined navigation equipment and, consequently, lessen the accuracy of user position and time solutions. This article reviews approaches to overcome this problem and presents simulations of positioning accuracy for combined equipment. It then discusses the basic options for time-offset determination and examines prediction accuracy, using both simulated and real measurement data. Copyright Questex Media Group Inc Numéro de notice : A2005-586 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27721 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
067-05031	SL	Revue	Centre de documentation	Revues en salle	Disponible