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Rapid PPP ambiguity resolution using GPS+GLONASS observations / Yanyan Liu in Journal of geodesy, vol 91 n° 4 (April 2017)
[article]
Titre : Rapid PPP ambiguity resolution using GPS+GLONASS observations Type de document : Article/Communication Auteurs : Yanyan Liu, Auteur ; Shirong Ye, Auteur ; Weiwei Song, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 441 - 455 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] code GLONASS
[Termes IGN] données GLONASS
[Termes IGN] données GPS
[Termes IGN] fractional cycle bias
[Termes IGN] positionnement ponctuel précis
[Termes IGN] résolution d'ambiguïté
[Termes IGN] signal GLONASS
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) Integer ambiguity resolution (IAR) in precise point positioning (PPP) using GPS observations has been well studied. The main challenge remaining is that the first ambiguity fixing takes about 30 min. This paper presents improvements made using GPS+GLONASS observations, especially improvements in the initial fixing time and correct fixing rate compared with GPS-only solutions. As a result of the frequency division multiple access strategy of GLONASS, there are two obstacles to GLONASS PPP-IAR: first and most importantly, there is distinct code inter-frequency bias (IFB) between satellites, and second, simultaneously observed satellites have different wavelengths. To overcome the problem resulting from GLONASS code IFB, we used a network of homogeneous receivers for GLONASS wide-lane fractional cycle bias (FCB) estimation and wide-lane ambiguity resolution. The integer satellite clock of the GPS and GLONASS was then estimated with the wide-lane FCB products. The effect of the different wavelengths on FCB estimation and PPP-IAR is discussed in detail. We used a 21-day data set of 67 stations, where data from 26 stations were processed to generate satellite wide-lane FCBs and integer clocks and the other 41 stations were selected as users to perform PPP-IAR. We found that GLONASS FCB estimates are qualitatively similar to GPS FCB estimates. Generally, 98.8% of a posteriori residuals of wide-lane ambiguities are within ±0.25 cycles for GPS, and 96.6% for GLONASS. Meanwhile, 94.5 and 94.4% of narrow-lane residuals are within 0.1 cycles for GPS and GLONASS, respectively. For a critical value of 2.0, the correct fixing rate for kinematic PPP is only 75.2% for GPS alone and as large as 98.8% for GPS+GLONASS. The fixing percentage for GPS alone is only 11.70 and 46.80% within 5 and 10 min, respectively, and improves to 73.71 and 95.83% when adding GLONASS. Adding GLONASS thus improves the fixing percentage significantly for a short time span. We also used global ionosphere maps (GIMs) to assist the wide-lane carrier-phase combination to directly fix the wide-lane ambiguity. Employing this method, the effect of the code IFB is eliminated and numerical results show that GLONASS FCB estimation can be performed across heterogeneous receivers. However, because of the relatively low accuracy of GIMs, the fixing percentage of GIM-aided GPS+GLONASS PPP ambiguity resolution is very low. We expect better GIM accuracy to enable rapid GPS+GLONASS PPP-IAR with heterogeneous receivers. Numéro de notice : A2017-108 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0975-9 En ligne : http://dx.doi.org/10.1007/s00190-016-0975-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84498
in Journal of geodesy > vol 91 n° 4 (April 2017) . - pp 441 - 455[article]Multi-GNSS precise point positioning (MGPPP) using raw observations / Teng Liu in Journal of geodesy, vol 91 n° 3 (March 2017)
[article]
Titre : Multi-GNSS precise point positioning (MGPPP) using raw observations Type de document : Article/Communication Auteurs : Teng Liu, Auteur ; Yunbin Yuan, Auteur ; Baocheng Zhang, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 253 - 268 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] correction ionosphérique
[Termes IGN] données BeiDou
[Termes IGN] données Galileo
[Termes IGN] données GLONASS
[Termes IGN] données GPS
[Termes IGN] erreur systématique inter-systèmes
[Termes IGN] horloge atomique
[Termes IGN] positionnement par GNSS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] simple différence
[Vedettes matières IGN] Traitement de données GNSSMots-clés libres : Multi-GNSS Experiment (MGEX) Résumé : (Auteur) A joint-processing model for multi-GNSS (GPS, GLONASS, BDS and GALILEO) precise point positioning (PPP) is proposed, in which raw code and phase observations are used. In the proposed model, inter-system biases (ISBs) and GLONASS code inter-frequency biases (IFBs) are carefully considered, among which GLONASS code IFBs are modeled as a linear function of frequency numbers. To get the full rank function model, the unknowns are re-parameterized and the estimable slant ionospheric delays and ISBs/IFBs are derived and estimated simultaneously. One month of data in April, 2015 from 32 stations of the International GNSS Service (IGS) Multi-GNSS Experiment (MGEX) tracking network have been used to validate the proposed model. Preliminary results show that RMS values of the positioning errors (with respect to external double-difference solutions) for static/kinematic solutions (four systems) are 6.2 mm/2.1 cm (north), 6.0 mm/2.2 cm (east) and 9.3 mm/4.9 cm (up). One-day stabilities of the estimated ISBs described by STD values are 0.36 and 0.38 ns, for GLONASS and BDS, respectively. Significant ISB jumps are identified between adjacent days for all stations, which are caused by the different satellite clock datums in different days and for different systems. Unlike ISBs, the estimated GLONASS code IFBs are quite stable for all stations, with an average STD of 0.04 ns over a month. Single-difference experiment of short baseline shows that PPP ionospheric delays are more precise than traditional leveling ionospheric delays. Numéro de notice : A2017-065 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0960-3 En ligne : http://dx.doi.org/10.1007/s00190-016-0960-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84290
in Journal of geodesy > vol 91 n° 3 (March 2017) . - pp 253 - 268[article]Multi-GNSS meteorology : real-time retrieving of atmospheric water vapor from BeiDou, Galileo, GLONASS, and GPS observations / Xingxing Li in IEEE Transactions on geoscience and remote sensing, vol 53 n° 12 (December 2015)
[article]
Titre : Multi-GNSS meteorology : real-time retrieving of atmospheric water vapor from BeiDou, Galileo, GLONASS, and GPS observations Type de document : Article/Communication Auteurs : Xingxing Li, Auteur ; Galina Dick, Auteur ; Cuixian Lu, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 6385 - 6393 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] correction troposphérique
[Termes IGN] données BeiDou
[Termes IGN] données Galileo
[Termes IGN] données GLONASS
[Termes IGN] données GPS
[Termes IGN] données météorologiques
[Termes IGN] positionnement par GNSS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] retard troposphérique zénithal
[Termes IGN] teneur intégrée en vapeur d'eau
[Termes IGN] vapeur d'eauRésumé : (auteur) The rapid development of multi-Global Navigation Satellite Systems (GNSSs, e.g., BeiDou, Galileo, GLONASS, and GPS) and the International GNSS Service (IGS) Multi-GNSS Experiment (MGEX) brings great opportunities and challenges for real-time determination of tropospheric zenith total delays (ZTDs) and integrated water vapor (IWV) to improve numerical weather prediction, particularly for nowcasting or severe weather event monitoring. In this paper, we develop a multi-GNSS model to fully exploit the potential of observations from all currently available GNSSs for enhancing real-time ZTD/IWV processing. A prototype multi-GNSS real-time ZTD/IWV monitoring system is also designed and realized at the Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences (GFZ) based on the precise point positioning technique. The ZTD and IWV derived from multi-GNSS stations are carefully analyzed and compared with those from collocated Very Long Baseline Interferometry and radiosonde stations. The performance of individual GNSS is assessed, and the significant benefit of multi-GNSS for real-time water vapor retrieval is also evaluated. The statistical results show that accuracy of several millimeters with high reliability is achievable for the multi-GNSS-based real-time ZTD estimates, which corresponds to about 1- to 1.5-mm accuracy for the IWV. The ZTD/IWV with improved accuracy and reliability would be beneficial for atmospheric sounding systems, particularly for time-critical geodetic and meteorological applications. Numéro de notice : A2015-844 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2015.2438395 En ligne : https://doi.org/10.1109/TGRS.2015.2438395 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79188
in IEEE Transactions on geoscience and remote sensing > vol 53 n° 12 (December 2015) . - pp 6385 - 6393[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2015121 SL Revue Centre de documentation Revues en salle Disponible GNSS-WARP software for real-time precise point positioning / Tomasz Hadas in Artificial satellites, vol 50 n° 2 (June 2015)
[article]
Titre : GNSS-WARP software for real-time precise point positioning Type de document : Article/Communication Auteurs : Tomasz Hadas, Auteur Année de publication : 2015 Article en page(s) : pp 59 - 76 Langues : Anglais (eng) Descripteur : [Termes IGN] données GLONASS
[Termes IGN] données GNSS
[Termes IGN] données GPS
[Termes IGN] logiciel de post-traitement GPS
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] positionnement ponctuel précis
[Termes IGN] temps réel
[Termes IGN] traitement de données GNSS
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) On April 1, 2013 IGS launched the real-time service providing products for Precise Point Positioning (PPP). The availability of real-time makes PPP a very powerful technique to process GNSS signals in real-time and opens a new PPP applications opportunities. There are still, however, some limitations of PPP, especially in the kinematic mode. A significant change in satellite geometry is required to efficiently de-correlate troposphere delay, receiver clock offset, and receiver height. In order to challenge PPP limitations, the GNSS-WARP (Wroclaw Algorithms for Real-time Positioning) software has been developed from scratch at Wroclaw University of Environmental and Life Science in Poland. This paper presents the GNSS-WARP software itself and some results of GNSS data analysis using PPP and PPP-RTK (Real-Time Kinematic) technique. The results of static and kinematic processing in GPS only and GPS + GLONASS mode with final and real-time products are presented. Software performance validation in postprocessing mode confirmed that the software can be considered as a state-ofthe- art software and used for further studies on PPP algorithm development. The real-time positioning test made it possible to assess the quality of real-time coordinates, which is a few millimeters for North, East, Up in static mode, a below decimeter in kinematic mode. The accuracy and precision of height estimates in kinematic mode were improved by constraining the solution with an external, near real-time troposphere model. The software also allows estimation of real-time ZTD, however, the obtained precision of 11.2 mm means that further improvements in the software, real-time products or processing strategy are required. Numéro de notice : A2015-285 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/arsa-2015-0005 En ligne : https://doi.org/10.1515/arsa-2015-0005 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76403
in Artificial satellites > vol 50 n° 2 (June 2015) . - pp 59 - 76[article]Subseasonal GNSS positioning errors / Jim Ray in Geophysical research letters, vol 40 n° 22 (November 2013)
[article]
Titre : Subseasonal GNSS positioning errors Type de document : Article/Communication Auteurs : Jim Ray, Auteur ; Jake Griffiths, Auteur ; Xavier Collilieux , Auteur ; Paul Rebischung , Auteur Année de publication : 2013 Article en page(s) : pp 5854 - 5860 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] bruit rose
[Termes IGN] coordonnées GNSS
[Termes IGN] crénelage
[Termes IGN] données GLONASS
[Termes IGN] élément d'orientation externe
[Termes IGN] variation saisonnière
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) Global Navigation Satellite System (GNSS) station coordinate errors over seasonal and longer time scales are known to be spatially and temporally correlated with flicker noise spectra. Overlaying this are strong annual and semiannual variations that cannot be explained by any single phenomenon. Next most prominent are harmonics of the GPS draconitic year with periods of (351.4/N) days. One explanation is that errors in the standard model for Earth orientation parameter (EOP) tidal variations near 12 and 24 h periods are absorbed into the resonant GPS orbit and daily EOP estimates, resulting mainly in draconitic and fortnightly alias signatures for 24 h product sampling. With the change in International GNSS Service (IGS) station coordinates from weekly to daily resolution in August 2012, it is now possible to study subseasonal performance. All IGS Analysis Centers (ACs) show fortnightly signals, but the resolution will not be sufficient to distinguish direct from aliased subdaily tidal error sources till two more years of data are available. Nevertheless, aliased errors from the subdaily EOP tide model are expected. All but one of the ACs that includes GLONASS data have signals at ~8 day periods, the ground repeat period for GLONASS orbits. This most likely arises from larger geographically correlated orbit errors for GLONASS. Two ACs possess unique short-period features that appear to be caused by peculiarities of their analysis strategies. Numéro de notice : A2013-795 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article DOI : 10.1002/2013GL058160 Date de publication en ligne : 08/11/2013 En ligne : http://dx.doi.org/10.1002/2013GL058160 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80235
in Geophysical research letters > vol 40 n° 22 (November 2013) . - pp 5854 - 5860[article]Documents numériques
en open access
Subseasonal GNSS Positionning ErrorsAdobe Acrobat PDF Méthodes de travail dans les réseaux GNSS, 3ème partie Méthodes du "statique multi-stations" / Romain Legros in XYZ, n° 134 (mars - mai 2013)PermalinkApport du système de navigation GLONASS à la surveillance de l'ionosphère au dessus de l'Europe / Emilie Pelletier (2013)PermalinkGLONASS today and tomorrow: Fully operational system modernizes for the multi-GNSS world / V. Davydov in GPS world, vol 23 n° 12 (December 2012)PermalinkComing Soon: the international GNSS real-time service / M. Caissy in GPS world, vol 23 n° 6 (June 2012)PermalinkMeasurement accuracy in Network-RTK / R. Emardson in Bulletin of geodesy and geomatics BGG, vol 69 n° 2 - 3 (December 2010)PermalinkRapid static positioning using GPS and GLONASS / Gerhard Beutler in Bulletin of geodesy and geomatics BGG, vol 69 n° 2 - 3 (December 2010)PermalinkIntérêts scientifiques de la campagne GLONASS IGEX-98 / Muhammad Ali Sammuneh (2001)Permalink