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A statistical characterization of the Galileo-to-GPS inter-system bias / Ciro Gioia in Journal of geodesy, vol 90 n° 11 (November 2016)  

Public [article]  inJournal of geodesy > vol 90 n° 11 (November 2016) . - pp 1279 - 1291 Titre : A statistical characterization of the Galileo-to-GPS inter-system bias Type de document : Article/Communication Auteurs : Ciro Gioia, Auteur ; Daniele Borio, Auteur Année de publication : 2016 Article en page(s) : pp 1279 - 1291 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement [Termes IGN] diffusion de données [Termes IGN] données Galileo [Termes IGN] échelle de temps [Termes IGN] erreur systématique inter-systèmes [Termes IGN] récepteur Galileo [Termes IGN] récepteur GPS [Termes IGN] signal Galileo Résumé : (Auteur) Global navigation satellite system operates using independent time scales and thus inter-system time offsets have to be determined to enable multi-constellation navigation solutions. GPS/Galileo inter-system bias and drift are evaluated here using different types of receivers: two mass market and two professional receivers. Moreover, three different approaches are considered for the inter-system bias determination: in the first one, the broadcast Galileo to GPS time offset is used to align GPS and Galileo time scales. In the second, the inter-system bias is included in the multi-constellation navigation solution and is estimated using the measurements available. Finally, an enhanced algorithm using constraints on the inter-system bias time evolution is proposed. The inter-system bias estimates obtained with the different approaches are analysed and their stability is experimentally evaluated using the Allan deviation. The impact of the inter-system bias on the position velocity time solution is also considered and the performance of the approaches analysed is evaluated in terms of standard deviation and mean errors for both horizontal and vertical components. From the experiments, it emerges that the inter-system bias is very stable and that the use of constraints, modelling the GPS/Galileo inter-system bias behaviour, significantly improves the performance of multi-constellation navigation. Numéro de notice : A2016-802 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0925-6 En ligne : http://dx.doi.org/10.1007/s00190-016-0925-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82586 [article]

Identifying a low-frequency oscillation in Galileo IOV pseudorange rates / Daniele Borio in GPS solutions, vol 20 n° 3 (July 2016)  

Public [article]  inGPS solutions > vol 20 n° 3 (July 2016) . - pp 363 - 372 Titre : Identifying a low-frequency oscillation in Galileo IOV pseudorange rates Type de document : Article/Communication Auteurs : Daniele Borio, Auteur ; Ciro Gioia, Auteur ; Neil Mitchison, Auteur Année de publication : 2016 Article en page(s) : pp 363 - 372 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] étalonnage en vol [Termes IGN] Galileo [Termes IGN] horloge atomique [Termes IGN] mesurage de pseudo-distance [Termes IGN] oscillateur [Termes IGN] performance [Termes IGN] vitesse Résumé : (Auteur) Galileo, the European global navigation satellite system, is in its in-orbit validation phase and the four satellites which have been available for some months now have allowed a preliminary analysis of the system performance. Previous studies have showed that Galileo will be able to provide pseudorange measurements more accurate than those provided by GPS. However, a similar improvement was not found for pseudorange rate observations in the velocity domain. This fact stimulated additional analysis of the velocity domain, and, in particular, an unintended oscillatory component was identified as the main error source in the velocity solution. The magnitude of such oscillation is less than 10 cm/s, and its period is in the order of few minutes. A methodology was developed to identify oscillatory components in the Galileo IOV pseudorange rate observables, and it was verified that the measurements from Galileo IOV PFM and Galileo IOV FM2 are affected by a small oscillatory disturbance. This disturbance stems from the architecture adopted for combining the frequency references provided by the two active clocks present in the Galileo satellites. The issue has been solved in Galileo IOV FM3 and Galileo IOV FM4, and the oscillatory component has been eliminated. We also propose a methodology for removing this unwanted component from the final velocity solution and for determining the performance that Galileo will be able to achieve. The analysis shows that Galileo velocity solution will provide a root-mean-square error of about 8 cm/s even in the limited geometry conditions achieved using only four satellites. This shows the potential of Galileo also in the determination of user velocity. Numéro de notice : A2016-630 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-015-0443-7 En ligne : http://dx.doi.org/10.1007/s10291-015-0443-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81833 [article]

A Galileo IOV assessment: measurement and position domain / Ciro Gioia in GPS solutions, vol 19 n° 2 (April 2015)  

Public [article]  inGPS solutions > vol 19 n° 2 (April 2015) . - pp 187 - 199 Titre : A Galileo IOV assessment: measurement and position domain Type de document : Article/Communication Auteurs : Ciro Gioia, Auteur ; Daniele Borio, Auteur ; Antonio Angrisano, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 187 - 199 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] GIOVE (satellite) [Termes IGN] mesurage de pseudo-distance [Termes IGN] test de performance Résumé : (auteur) The European GNSS, Galileo, is currently in its in-orbit validation (IOV) phase where four satellites are finally available for computing the user position. In this phase, the analysis of the measurements and position velocity and time (PVT) obtained from the IOV satellites can provide insight into the potentialities of the Galileo system. A methodology is suggested for the analysis of the Galileo IOV pseudorange and pseudorange rates collected from the E1 and E5 frequencies. Several days of data were collected and processed to determine figures of merit such as root mean square and maximum errors of the Galileo observables. From the analysis, it emerges that Galileo is able to achieve better accuracy than GPS. A thorough analysis of the PVT performance is also carried out using broadcast ephemerides. Galileo and GPS PVTs are compared under similar geometry conditions showing the potential of the Galileo system. Numéro de notice : A2015-206 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-014-0379-3 En ligne : https://doi.org/10.1007/s10291-014-0379-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76020 [article]