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Titre : Multi-GNSS Hybridization for Precise Positioning Type de document : Thèse/HDR Auteurs : Georgia Katsigianni, Auteur ; Félix Perosanz, Directeur de thèse ; Sylvain Loyer, Directeur de thèse Editeur : Toulouse : Université de Toulouse 3 Paul Sabatier Année de publication : 2019 Importance : 143 p. Format : 21 x 30 cm Note générale : Thèse en vue de l'obtention du Doctorat de l'Université de Toulouse 3 Paul Sabatier, Spécialité Sciences de la Terre et des Planètes Solides Langues : Anglais (eng) Descripteur : [Termes IGN] données Galileo
[Termes IGN] données GPS
[Termes IGN] orbitographie
[Termes IGN] positionnement cinématique
[Termes IGN] positionnement par GNSS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] résolution d'ambiguïté
[Vedettes matières IGN] Traitement de données GNSSIndex. décimale : THESE Thèses et HDR Résumé : (auteur) GNSS are widely used for precise positioning applications of geosciences and especially space geodesy. So far, mainly the existing GPS was extensively used for scientific applications. With the arrival of the new European Galileo system it became imperative to include the new system in the studies and check the new capabilities that it will bring as a system alone and as combined together with the others in a Multi-GNSS processing. The CNES/CLS analysis center of the IGS is weekly calculating GNSS (GPS, GLONASS and Galileo) products that can be taken from any kind of user to perform precise positioning. A way to achieve the best accuracy possible is to resolve the unknown integer ambiguities of the phase measurements. Up until now, the CNES/CLS was performing ambiguity resolution to the GPS system using the zero-difference method. In this way they are able to deliver precise satellite orbits and precise clock products with phase fixed ambiguities. The goal of this work was to implement and validate if the method can be also applied for the Galileo system. The method applied from the CNES/CLS is consisting of two further steps. The first one is the resolution of the Wide-Lane ambiguities. The Galileo Wide-Lane satellite biases have been proven to be stable over long periods of time. In addition, there is homogeneity in the way they are observed from different types of receivers. These findings were used and the Wide-Lane biases were successfully resolved with nearly 100% success rate percentage. The second step of zero-difference method is the Narrow-Lane ambiguity resolution. This step was executed for the Galileo system together with the GPS system in a Multi-GNSS Precise Orbit Determination processing. Galileo ambiguity fixing success percentage is around 93%, nearly similar to the one of the GPS system. The integer property of the Galileo phase clocks is demonstrated. Both orbit overlaps and orbit validation using SLR validation methods showed that ambiguity resolution improves mainly in the normal and the along track direction. Galileo orbit overlaps in 3D RMS showed an improvement of around 50%, from around 7 cm to 3.5 cm. The results of this work were used by the CNES/CLS IGS AC that has announced the delivery of weekly Galileo precise orbits, clocks and Wide-Lane satellite biases. A new method is also introduced on how to compare ambiguity resolution results for a common overlapping period. This method is also used to speculate the agreement and the disagreement between two different daily solutions. Finally, it was examined the post-processed kinematic PPP and PPP-AR using Galileo-only, GPSonly and Multi-GNSS (GPS + Galileo) constellations. The interest was to validate the accuracy for each GNSS system individually but also of their combination. Results showed that Galileoonly positioning accuracy is nearly at the same level of accuracy as GPS-only. The use of Galileo system improves the performance of the GPS positioning giving mm level repeatability. The contribution of Galileo ameliorates the positioning accuracy around 30% in all directions(comparison GPS PPP-AR and Multi-GNSS PPP-AR). This proved that the Galileo constellation together with GPS will give improved precise positioning with respect to the current GPS-only.
All these are indications that the Galileo system will contribute to precise positioning required by geoscience applications through a Multi-GNSS (GPS + Galileo) solution.Note de contenu : 1- Introduction
2- GNSS in science
3- GNSS measurements
4- Galileo Wide-Lane AR
5- Galileo Narrow-Lane AR
6- Precise Point Positioning
7- Conclusions and SuggestionsNuméro de notice : 28511 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse française Note de thèse : Thèse de Doctorat : Sciences de la Terre et des Planètes Solides : Toulouse 3 : 2019 Organisme de stage : Geosciences Environnement Toulouse nature-HAL : Thèse DOI : sans En ligne : http://www.theses.fr/2019TOU30209 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97142 Evaluation of three ionospheric delay computation methods for ground-based GNSS receivers / Liang Chen in GPS solutions, vol 22 n° 4 (October 2018)
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Titre : Evaluation of three ionospheric delay computation methods for ground-based GNSS receivers Type de document : Article/Communication Auteurs : Liang Chen, Auteur ; Wenting Yi, Auteur ; Weiwei Song, Auteur ; Chuang Shi, Auteur ; Yidong Lou, Auteur ; Cheng Cao, Auteur Année de publication : 2018 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse comparative
[Termes IGN] erreur systématique inter-systèmes
[Termes IGN] positionnement ponctuel précis
[Termes IGN] récepteur GNSS
[Termes IGN] retard ionosphèrique
[Vedettes matières IGN] Traitement de données GNSSMots-clés libres : carrier-to-code leveling (CCL) method ionospheric-free Hatch–Melbourne–Wubbena (HMW) function Résumé : (Auteur) GNSS observables for ionospheric estimation are commonly based on carrier-to-code leveling (CCL) and precise point positioning (PPP) methods. The CCL method is a geometry-free method which uses carrier phase to level pseudorange observation for decreasing multipath error and observation noise. However, the ionospheric observable based on the CCL has been proven to be affected by leveling errors. The leveling errors are caused by pseudorange multipath and intraday variation of receiver DCB. To obtain more accurate ionospheric observable, the PPP method takes advantage of precise satellite-to-ground range for retrieving slant total electron content and is less affected by the leveling errors. Previous studies have only proven that the ionospheric observables extracted by the two methods are affected by the leveling errors. The influence on ionospheric observable by the pseudorange inter-receiver satellite bias (IRSB) of the receiver has not been taken into consideration. Also, the magnitude of the differences between the ionospheric observables extracted by the two methods has also not been given. In this work, three methods, namely, the CCL, the conventional ionospheric-free PPP method which uses the ionospheric-free Hatch–Melbourne–Wubbena (HMW) function, and the University of Calgary (UOFC) PPP method, are selected to analyze and compare the differences of ionospheric observables and the global ionospheric maps, using a large number of measured data from international GNSS service global stations. Experimental results show that the accuracy of ionospheric observables obtained by the three methods is not only related to the leveling error, but also pseudorange IRSB. The IRSB of the receiver exerts a major effect on the ionospheric observables obtained by the CCL method and a minor effect on the ionospheric observables obtained by the HMW and UOFC methods. The accuracies in the latter case are similar and superior to those obtained by the CCL. The differences of the ionospheric observables obtained by the CCL and UOFC methods, or the CCL and HMW methods, are at decimeter level, whereas the difference of the ionospheric observables obtained by the UOFC and HMW methods is at centimeter level. The UOFC method presented the highest single-frequency pseudorange positioning accuracy using estimated global ionospheric products, followed by the HMW and the CCL methods which presented the lowest positioning accuracy. Numéro de notice : A2018-376 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-018-0788-9 Date de publication en ligne : 01/10/2018 En ligne : https://doi.org/10.1007/s10291-018-0788-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90780
in GPS solutions > vol 22 n° 4 (October 2018)[article]PPPH : a MATLAB-based software for multi-GNSS precise point positioning analysis / Berkay Bahadur in GPS solutions, vol 22 n° 4 (October 2018)
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Titre : PPPH : a MATLAB-based software for multi-GNSS precise point positioning analysis Type de document : Article/Communication Auteurs : Berkay Bahadur, Auteur ; Metin Nohutcu, Auteur Année de publication : 2018 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] affaiblissement géométrique de la précision
[Termes IGN] données GNSS
[Termes IGN] erreur en position
[Termes IGN] horloge du récepteur
[Termes IGN] Matlab
[Termes IGN] positionnement ponctuel précis
[Termes IGN] retard troposphérique zénithal
[Vedettes matières IGN] Traitement de données GNSSRésumé : (Auteur) The integration of different GNSS constellations offers considerable opportunities to improve Precise Point Positioning (PPP) performance. Being aware of the limited number of the alternatives that utilize the potential advantages of the multi-constellation and multi-frequency GNSS, we developed a MATLAB-based GNSS analysis software, named PPPH. PPPH is capable of processing GPS, GLONASS, Galileo and BeiDou data, and forming their different combinations depending on user’s preference. Thanks to its user-friendly graphical interface, PPPH allows users to determine a variety of processing options and parameters. In addition to an output file including the estimated parameters for every single epoch, PPPH also presents several analyzing and plotting tools for evaluating the results, such as positioning error, tropospheric zenith total delay, receiver clock estimation, satellite number, dilution of precisions. On the other hand, we conducted experimental tests to both validate the performance of PPPH and assess the potential benefits of multi-GNSS on PPP. The results indicate that PPPH provides comparable PPP solution with the general standards and also contributes to the improvement of PPP performance with the integration of multi-GNSS. Consequently, we introduce a GNSS analysis software that is easy to use, has a robust performance and is open to progress with its modular structure. Numéro de notice : A2018-377 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-018-0777-z Date de publication en ligne : 18/08/2018 En ligne : https://doi.org/10.1007/s10291-018-0777-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90781
in GPS solutions > vol 22 n° 4 (October 2018)[article]Differential positioning based on the orthogonal transformation algorithm with GNSS multi-system / Xiao Liang in GPS solutions, vol 22 n° 3 (July 2018)
[article]
Titre : Differential positioning based on the orthogonal transformation algorithm with GNSS multi-system Type de document : Article/Communication Auteurs : Xiao Liang, Auteur ; Zhigang Huang, Auteur ; Honglei Qin, Auteur Année de publication : 2018 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] ambiguïté entière
[Termes IGN] erreur instrumentale
[Termes IGN] erreur systématique
[Termes IGN] filtre de Kalman
[Termes IGN] méthode des moindres carrés
[Termes IGN] positionnement différentiel
[Termes IGN] résolution d'ambiguïté
[Termes IGN] simple différence
[Vedettes matières IGN] Traitement de données GNSSRésumé : (Auteur) Combining global navigation satellite systems (GNSSs) will significantly increase the number of visible satellites and, thus, will improve the geometry of observed satellites, resulting in improved positioning reliability and accuracy. We focus on GNSS multi-system differential positioning based on a single-system orthogonal transformation algorithm. The orthogonal transformation algorithm using single-difference measurements is proposed to avoid the high correlation between measurements and the unnecessary prominence to the reference satellite in double-difference positioning. In addition, the algorithm uses a more straightforward recursive least squares method to avoid the effect of uncertainties of the Kalman filter. We discuss the model differences between combined system positioning and single-system positioning and verify that the combining observations of different systems should start to be used after clock biases have been reduced, respectively. Moreover, as to rising and setting of satellites in multi-system differential positioning, we propose to use matrix transform to separate the setting satellites of combined systems at an epoch. This can avoid the correlation of initial integer ambiguity vectors of different systems. The experimental results show that the proposed method can handle the change of satellites automatically and combine multiple systems for reliable and accuracy differential positioning. The method especially outperforms the basic single-system orthogonal transformation positioning and traditional multi-system double-difference positioning in a complex environment. Numéro de notice : A2018-371 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-018-0754-6 Date de publication en ligne : 02/07/2018 En ligne : https://doi.org/10.1007/s10291-018-0754-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90763
in GPS solutions > vol 22 n° 3 (July 2018)[article]A sequential network approach for estimating GPS satellite phase biases at the PPP-AR producer-side / Omid Kamali in GPS solutions, vol 22 n° 3 (July 2018)
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Titre : A sequential network approach for estimating GPS satellite phase biases at the PPP-AR producer-side Type de document : Article/Communication Auteurs : Omid Kamali, Auteur ; Marc Cocard, Auteur ; Rock Santerre, Auteur Année de publication : 2018 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] données GPS
[Termes IGN] erreur systématique
[Termes IGN] phase GNSS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] résolution d'ambiguïté
[Termes IGN] station permanente
[Vedettes matières IGN] Traitement de données GNSSRésumé : (Auteur) Ambiguity resolution (AR) in precise point positioning (PPP) requires precise satellite orbit, clocks, and phase biases corrections. Satellite phase biases are fractional hardware corrections which help to retrieve the un-differenced integer carrier phase ambiguities. Satellite corrections can be obtained from the international GNSS service (IGS) or estimated by correction providers called producer-side. We introduce a new PPP-AR observation model and a new sequential network algorithm (SNA) to estimate satellite phase biases. The new model is fully compatible with standard IGS satellite correction products, and it takes advantage of currently available IGS global ionosphere maps to improve the stability of corrections estimation. Furthermore, the proposed model is full-rank per-frequency and per-site and this method simplifies the integration of any additional frequency or site observables in the system of equations. The per-site satellite phase biases method allows users to customize their network solution. In many cases, users only have to estimate the phase biases of a few satellites estimated by few stations to resolve ambiguities of their observed satellites. The novel two-step algorithm provides a good balance between the computational burden, the computer memory load, the efficiency of handling parameters, and the precise estimation of correction parameters. The proposed PPP-AR model and the SNA performance is then validated by estimating satellite phase biases with 1 year of GPS data from a sub-network of IGS stations. A rigorous a posteriori statistical test is performed using data from an independent GPS network. As a result, the precision of WL and L1 ambiguities was improved significantly with the confidence level of P > 99.99% by applying the estimated phase bias corrections to phase observables. Numéro de notice : A2018-374 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-018-0724-z Date de publication en ligne : 11/04/2018 En ligne : https://doi.org/10.1007/s10291-018-0724-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90778
in GPS solutions > vol 22 n° 3 (July 2018)[article]Carrier phase bias estimation of geometry-free linear combination of GNSS signals for ionospheric TEC modeling / Anna Krypiak-Gregorczyk in GPS solutions, vol 22 n° 2 (April 2018)PermalinkCharacterizing noise in daily GPS position time series with overlapping Hadamard variance and maximum likelihood estimation / Chang Xu in Survey review, vol 49 n° 355 (October 2017)PermalinkPeriodic signals in a pseudo-kinematic GPS coordinate time series depending on the antenna phase centre model – TRM55971.00 TZGD antenna case study / Karol Dawidowicz in Survey review, vol 49 n° 355 (October 2017)PermalinkERTK: extra-wide-lane RTK of triple-frequency GNSS signals / Bofeng Li in Journal of geodesy, vol 91 n° 9 (September 2017)PermalinkImproving BeiDou real-time precise point positioning with numerical weather models / Cuixian Lu in Journal of geodesy, vol 91 n° 9 (September 2017)PermalinkPerformance evaluation of ionospheric time delay forecasting models using GPS observations at a low-latitude station / G. Sivavaraprasad in Advances in space research, vol 60 n° 2 (15 July 2017)PermalinkMultipath detection based on single orthogonal dual linear polarized GNSS antenna / Ke Zhang in GPS solutions, vol 21 n° 3 (July 2017)PermalinkAn example and analysis for ambiguity resolution in the indoor ZigBee positioning system / Joanna Janicka in Reports on geodesy and geoinformatics, vol 103 n° 1 (June 2017)PermalinkGPS code phase variations (CPV) for GNSS receiver antennas and their effect on geodetic parameters and ambiguity resolution / Tobias Kersten in Journal of geodesy, vol 91 n° 6 (June 2017)PermalinkMultivariate analysis of GPS position time series of JPL second reprocessing campaign / Ali Reza Amiri-Simkooei in Journal of geodesy, vol 91 n° 6 (June 2017)PermalinkIntegrating uncertainty propagation in GNSS radio occultation retrieval: From bending angle to dry-air atmospheric profiles / Jakob Schwarz in Earth and space science, vol 4 n° 4 (April 2017)PermalinkIonospheric error contribution to GNSS single-frequency navigation at the 2014 solar maximum / Raul Orus Perez in Journal of geodesy, vol 91 n° 4 (April 2017)PermalinkRapid PPP ambiguity resolution using GPS+GLONASS observations / Yanyan Liu in Journal of geodesy, vol 91 n° 4 (April 2017)PermalinkMulti-GNSS precise point positioning (MGPPP) using raw observations / Teng Liu in Journal of geodesy, vol 91 n° 3 (March 2017)PermalinkStudy of the effects on GPS coordinate time series caused by higher-order ionospheric corrections calculated using the DIPOLE model / Liansheng Deng in Geodesy and Geodynamics, vol 8 n° 2 (March 2017)PermalinkPermalinkMulti-technique combination of space geodesy observations: Impact of the Jason-2 satellite on the GPS satellite orbits estimation / Myriam Zoulida in Advances in space research, vol 58 n° 7 (October 2016)PermalinkQuantitative assessment of meteorological and tropospheric Zenith Hydrostatic Delay models / Di Zhang in Advances in space research, vol 58 n° 6 (September 2016)PermalinkTaking correlations in GPS least squares adjustments into account with a diagonal covariance matrix / Gaël Kermarrec in Journal of geodesy, vol 90 n° 9 (September 2016)PermalinkGNSS multipath detection using three-frequency signal-to-noise measurements / Philip R.R. Strode in GPS solutions, vol 20 n° 3 (July 2016)Permalink