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Analysis of GPS satellite clock prediction performance with different update intervals and application to real-time PPP / H. Yang in Survey review, vol 51 n° 364 (January 2019)
[article]
Titre : Analysis of GPS satellite clock prediction performance with different update intervals and application to real-time PPP Type de document : Article/Communication Auteurs : H. Yang, Auteur ; C. Xu, Auteur ; Yang Gao, Auteur Année de publication : 2019 Article en page(s) : pp 43 - 52 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] horloge du satellite
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] positionnement ponctuel précis
[Termes IGN] prédiction
[Termes IGN] temps réelRésumé : (Auteur) The GPS satellite clock offset prediction is investigated and applied to a real-time PPP system. First, the current situation of GPS satellite clock is introduced and analysed with respect to their stability. Then the satellite clock prediction with different update intervals is presented, in which the satellite clock day boundary jump is addressed. Afterwards, the investigation of the satellite clock prediction model for GPS satellite IIF clocks is carried out and the effects of periodic terms are discussed. After that, the verification of the satellite clock offset prediction will be carried out both in the time and positioning domain. Positioning accuracy at 0.021, 0.049, and 0.017 m in the east, north, and vertical directions can be obtained for 6-h static positioning using the predicted clock offset updating every hour, while the 3D RMS for kinematic real-time PPP is 0.360 m, with 28% improvement over that utilising the IGU predicted products. Numéro de notice : A2019-188 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2017.1359473 Date de publication en ligne : 03/08/2017 En ligne : https://doi.org/10.1080/00396265.2017.1359473 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92620
in Survey review > vol 51 n° 364 (January 2019) . - pp 43 - 52[article]Enhancing real-time precise point positioning time and frequency transfer with receiver clock modeling / Yulong Ge in GPS solutions, vol 23 n° 1 (January 2019)
[article]
Titre : Enhancing real-time precise point positioning time and frequency transfer with receiver clock modeling Type de document : Article/Communication Auteurs : Yulong Ge, Auteur ; Feng Zhou, Auteur ; Tianjun Liu, Auteur ; et al., Auteur Année de publication : 2019 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] horloge du récepteur
[Termes IGN] positionnement par GPS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] temps réel
[Termes IGN] variance d'AllanRésumé : (Auteur) Thanks to the international GNSS service (IGS), which has provided an open-access real-time service (RTS) since 2013, real-time precise point positioning (RT-PPP) has become a major topic in the time community. Currently, a few scholars have studied RT-PPP time transfer, and the correlation of the receiver clock offsets between adjacent epochs have not been considered. We present a receiver clock offset model that considers the correlation of the receiver clock offsets between adjacent epochs using an a priori value. The clock offset is estimated using a between-epoch constraint model rather than a white noise model. This approach is based on two steps. First, the a priori noise variance is based on the Allan variance of the receiver clock offset derived from GPS PPP solutions with IGS final products. Second, by applying the between-epoch constraint model, the RT-PPP time transfer is achieved. Our numerical analyses clarify how the approach performs for RT-PPP time and frequency transfer. Based on five commonly used RTS products and six IGS stations, two conclusions are obtained straightforwardly. First, all RT-PPP solutions with different real-time products are capable of time transfer. The standard deviation (STD) values of the clock difference between the PPP solutions with respect to the IGS final clock products are less than 0.3 ns. Second, the STD values are reduced significantly by applying our approach. The reduction percent of STD values ranges from 4.0 to 35.5%. Moreover, the largest improvement ratio of frequency stability is 12 as compared to the solution of the white noise model. Note that the receiver clock offset from IGS final clock products is regarded as a reference. Numéro de notice : A2019-052 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-018-0814-y Date de publication en ligne : 19/12/2018 En ligne : https://doi.org/10.1007/s10291-018-0814-y Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92081
in GPS solutions > vol 23 n° 1 (January 2019)[article]Estimating and assessing Galileo satellite fractional cycle bias for PPP ambiguity resolution / Guorui Xiao in GPS solutions, vol 23 n° 1 (January 2019)
[article]
Titre : Estimating and assessing Galileo satellite fractional cycle bias for PPP ambiguity resolution Type de document : Article/Communication Auteurs : Guorui Xiao, Auteur ; Pan Li, Auteur ; Lifen Sui, Auteur ; et al., Auteur Année de publication : 2019 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] ambiguïté entière
[Termes IGN] données Galileo
[Termes IGN] erreur systématique
[Termes IGN] positionnement par Galileo
[Termes IGN] positionnement ponctuel précis
[Termes IGN] résolution d'ambiguïtéRésumé : (Auteur) Due to the rapid deployment of the Galileo constellation, Galileo is now able to contribute to GNSS precise point positioning (PPP) ambiguity resolution (AR) with 17 operational satellites as of December 2017. We estimate the satellite fractional cycle bias (FCB) based on globally distributed MGEX stations and assess the Galileo FCB quality by a comparison with that of GPS and BDS. Results of 60 days indicate that the quality of Galileo wide-lane (WL) FCB is better than GPS and BDS in terms of data usage rate, residual distribution, as well as standard deviation of daily estimates. The RMS of Galileo WL FCB residuals is 0.071 cycles, while that of GPS and BDS are 0.089 and 0.117 cycles, respectively. The standard deviation of Galileo daily WL FCB is 0.010 cycles, while that of GPS and BDS is 0.018 and 0.043 cycles. We attribute the better quality of Galileo WL FCB to its signal modulation, AltBOC, which significantly compresses the multipath effect for pseudorange measurement. Within the Galileo constellation, the performance of In-Orbit Validation (IOV) satellites WL FCB is worse than that of Full Operational Capability (FOC) satellites as a result of a reduction in the power of the transmitted signal. The performance of the two highly eccentric satellites is comparable to other FOC satellites. The overall quality of Galileo narrow-lane (NL) FCB is slightly worse than that of GPS but better than that of BDS. The RMS of Galileo NL FCB residuals is 0.062 cycles, while that for GPS and BDS is 0.050 and 0.086 cycles respectively. In addition, the NL FCB quality of FOC, IOV (except E19), as well as the two eccentric satellites, shows no significant difference in terms of data usage rates and residuals. Galileo PPP AR solutions are conducted at 20 MGEX stations with 3-h sessions for 10 days. The positional biases of AR solutions are 0.7, 0.6, and 2.1 cm for east, north and up components respectively, while those for float solutions are 2.1, 1.1, and 2.7 cm, corresponding to the improvements of 67, 45, and 22%, respectively. These results demonstrate that, currently, Galileo FCB can be estimated with accuracy comparable with GPS and BDS, and the Galileo observations can bring an obvious benefit to ambiguity-fixed PPP. Numéro de notice : A2019-057 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-018-0793-z Date de publication en ligne : 19/10/2018 En ligne : https://doi.org/10.1007/s10291-018-0793-z Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92086
in GPS solutions > vol 23 n° 1 (January 2019)[article]Estimations of GNSS receiver internal delay using precise point positioning algorithm / Natchapan Pothikunkupatarak in Journal of applied geodesy, vol 13 n° 1 (January 2019)
[article]
Titre : Estimations of GNSS receiver internal delay using precise point positioning algorithm Type de document : Article/Communication Auteurs : Natchapan Pothikunkupatarak, Auteur ; Thayathip Thongtan, Auteur ; Chalermchon Satirapod, Auteur Année de publication : 2019 Article en page(s) : pp 41 - 46 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Métrologie
[Termes IGN] erreur instrumentale
[Termes IGN] positionnement ponctuel précis
[Termes IGN] récepteur GNSSRésumé : (Auteur) Random and systematic errors affect navigation satellite observations on both pseudo-range and carrier phase. These errors are originated at satellites, propagation path and receivers. This study focuses on the GNSS receiver internal delay determination resulting from the receiver’s electronics circuit. The characterisation of the delay in the GNSS geodetic receivers is essential to enhance the accuracy for the time transfer and time comparisons as part of GNSS integrity chain determinations. The purpose of GNSS receiver internal delay at the National Institute of Metrology (Thailand), NIMT, is to estimate the characteristics and performances of the GNSS geodetic receiver used for international time comparisons. The experiments are simultaneously observed GNSS satellites by a GPS and a GNSS receivers and two separate antennas with short baseline (around 6 metres), where both receivers are connected to the identical external caesium frequency standard maintained as time and frequency standard of Thailand. The GPS receiver is well-defined for its receiver internal delay on the pseudo-range observation of C1, through comparisons using an internationally recognised method, while the geodetic GNSS receiver is to be defined on its receiver internal delay. These experiment observations started from 26 December 2017 to 17 January 2018 at NIMT, Pathumthani, Thailand. The determined unknowns are receiver position, receiver clock offset, tropospheric delay through the geodetic technique of static Precise Point Positioning observations with Bernese GNSS software version 5.2. Later the receiver internal delay of NIMT is computed and analysed. The receiver internal delay on GPS C1 code is successfully characterised, resulted as 346.0 nanoseconds as of this experiment. Numéro de notice : A2019-133 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1515/jag-2018-0020 Date de publication en ligne : 20/09/2018 En ligne : https://doi.org/10.1515/jag-2018-0020 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92463
in Journal of applied geodesy > vol 13 n° 1 (January 2019) . - pp 41 - 46[article]Improving multi-GNSS ultra-rapid orbit determination for real-time precise point positioning / Xingxing Li in Journal of geodesy, vol 93 n° 1 (January 2019)
[article]
Titre : Improving multi-GNSS ultra-rapid orbit determination for real-time precise point positioning Type de document : Article/Communication Auteurs : Xingxing Li, Auteur ; Xinghan Chen, Auteur ; Maorong Ge, Auteur ; Harald Schuh, Auteur Année de publication : 2019 Article en page(s) : pp 45 - 64 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] délai d'obtention de la première position
[Termes IGN] orbite précise
[Termes IGN] orbitographie
[Termes IGN] positionnement par BeiDou
[Termes IGN] positionnement par Galileo
[Termes IGN] positionnement par GLONASS
[Termes IGN] positionnement par GNSS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] Quasi-Zenith Satellite System
[Termes IGN] temps réelRésumé : (auteur) Currently, with the rapid development of multi-constellation Global Navigation Satellite Systems (GNSS), the real-time positioning and navigation are undergoing dramatic changes with potential for a better performance. To provide more precise and reliable ultra-rapid orbits is critical for multi-GNSS real-time positioning, especially for the three merging constellations Beidou, Galileo and QZSS which are still under construction. In this contribution, we present a five-system precise orbit determination (POD) strategy to fully exploit the GPS + GLONASS + BDS + Galileo + QZSS observations from CDDIS + IGN + BKG archives for the realization of hourly five-constellation ultra-rapid orbit update. After adopting the optimized 2-day POD solution (updated every hour), the predicted orbit accuracy can be obviously improved for all the five satellite systems in comparison to the conventional 1-day POD solution (updated every 3 h). The orbit accuracy for the BDS IGSO satellites can be improved by about 80, 45 and 50% in the radial, cross and along directions, respectively, while the corresponding accuracy improvement for the BDS MEO satellites reaches about 50, 20 and 50% in the three directions, respectively. Furthermore, the multi-GNSS real-time precise point positioning (PPP) ambiguity resolution has been performed by using the improved precise satellite orbits. Numerous results indicate that combined GPS + BDS + GLONASS + Galileo (GCRE) kinematic PPP ambiguity resolution (AR) solutions can achieve the shortest time to first fix (TTFF) and highest positioning accuracy in all coordinate components. With the addition of the BDS, GLONASS and Galileo observations to the GPS-only processing, the GCRE PPP AR solution achieves the shortest average TTFF of 11 min with 7∘ cutoff elevation, while the TTFF of GPS-only, GR, GE and GC PPP AR solution is 28, 15, 20 and 17 min, respectively. As the cutoff elevation increases, the reliability and accuracy of GPS-only PPP AR solutions decrease dramatically, but there is no evident decrease for the accuracy of GCRE fixed solutions which can still achieve an accuracy of a few centimeters in the east and north components. Numéro de notice : A2019-032 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-018-1138-y Date de publication en ligne : 27/03/2018 En ligne : https://doi.org/10.1007/s00190-018-1138-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91969
in Journal of geodesy > vol 93 n° 1 (January 2019) . - pp 45 - 64[article]LEO enhanced Global Navigation Satellite System (LeGNSS) for real-time precise positioning services / Bofeng Li in Advances in space research, vol 63 n° 1 (1 January 2019)PermalinkPermalinkObjets et relations spatiales composites et prise en compte du vague pour interpréter un référencement spatial indirect / Mattia Bunel in Revue internationale de géomatique, vol 29 n° 1 (janvier - mars 2019)PermalinkQuality assessment of CNES real-time ionospheric products / Zhixi Nie in GPS solutions, vol 23 n° 1 (January 2019)PermalinkReal-time capturing of seismic waveforms using high-rate BDS, GPS and GLONASS observations: the 2017 Mw 6.5 Jiuzhaigou earthquake in China / Xingxing Li in GPS solutions, vol 23 n° 1 (January 2019)PermalinkPermalinkRTK and PPP-RTK using smartphones: From short-baseline to long-baseline applications / Francesco Darugna (2019)PermalinkEnhanced local ionosphere model for multi-constellations single frequency precise point positioning applications: Egyptian case study / Emad El Manaily in Artificial satellites, vol 53 n° 4 (December 2018)PermalinkGPS precise point positioning for UAV photogrammetry / Ben Grayson in Photogrammetric record, vol 33 n° 164 (December 2018)PermalinkPerformance analysis of PPP positioning method by using IGS real-time service / Tatjana Kuzmić in Geodetski vestnik, vol 62 n° 4 (December 2018 - February 2019)Permalink