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Ionospheric corrections tailored to the Galileo High Accuracy Service / Adria Rovira-Garcia in Journal of geodesy, vol 95 n° 12 (December 2021)
[article]
Titre : Ionospheric corrections tailored to the Galileo High Accuracy Service Type de document : Article/Communication Auteurs : Adria Rovira-Garcia, Auteur ; C.C. Timoté, Auteur ; José Miguel Juan, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 130 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] correction ionosphérique
[Termes IGN] décalage d'horloge
[Termes IGN] erreur systématique interfréquence d'horloge
[Termes IGN] GalileoSat
[Termes IGN] mesurage de phase
[Termes IGN] modèle ionosphérique
[Termes IGN] positionnement par Galileo
[Termes IGN] positionnement ponctuel précis
[Termes IGN] résolution d'ambiguïté
[Termes IGN] retard ionosphèriqueRésumé : (auteur) The Galileo High Accuracy Service (HAS) is a new capability of the European Global Navigation Satellite System that is currently under development. The Galileo HAS will start providing satellite orbit and clock corrections (i.e. non-dispersive effects) and soon it will also correct dispersive effects such as inter-frequency biases and, in its full capability, ionospheric delay. We analyse here an ionospheric correction system based on the fast precise point positioning (Fast-PPP) and its potential application to the Galileo HAS. The aim of this contribution is to present some recent upgrades to the Fast-PPP model, with the emphasis on the model geometry and the data used. The results show the benefits of integer ambiguity resolution to obtain unambiguous carrier phase measurements as input to compute the Fast-PPP model. Seven permanent stations are used to assess the errors of the Fast-PPP ionospheric corrections, with baseline distances ranging from 100 to 1000 km from the reference receivers used to compute the Fast-PPP corrections. The 99% of the GPS and Galileo errors in well-sounded areas and in mid-latitude stations are below one total electron content unit. In addition, large errors are bounded by the error prediction of the Fast-PPP model, in the form of the variance of the estimation of the ionospheric corrections. Therefore, we conclude that Fast-PPP is able to provide ionospheric corrections with the required ionospheric accuracy, and realistic confidence bounds, for the Galileo HAS. Numéro de notice : A2021-854 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-021-01581-x Date de publication en ligne : 21/11/2021 En ligne : https://doi.org/10.1007/s00190-021-01581-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99059
in Journal of geodesy > vol 95 n° 12 (December 2021) . - n° 130[article]Real-time GNSS precise point positioning using improved robust adaptive Kalman filter / Abdelsatar Elmezayen in Survey review, Vol 53 n° 381 (November 2021)
[article]
Titre : Real-time GNSS precise point positioning using improved robust adaptive Kalman filter Type de document : Article/Communication Auteurs : Abdelsatar Elmezayen, Auteur ; Ahmed El-Rabbany, Auteur Année de publication : 2021 Article en page(s) : pp 528 - 542 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] erreur de positionnement
[Termes IGN] filtre adaptatif
[Termes IGN] filtre de Kalman
[Termes IGN] phase
[Termes IGN] positionnement par Galileo
[Termes IGN] positionnement par GNSS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] temps réel
[Termes IGN] valeur aberranteRésumé : (Auteur) Multi-constellation GNSS precise point positioning (PPP) typically uses the extended Kalman filter (EKF) for kinematic applications. Unfortunately, the obtained positioning accuracy in this approach is prone to errors caused by measurement outliers and the system’s dynamic model. An adaptive robust Kalman filter (RKF) was recently developed to mitigate these errors. However, RKF uses empirical values as detection thresholds for the outliers, which requires the measurements to be from the same constellation and of equal precision to obtain an optimal PPP solution. The classification robust adaptive Kalman filter (CAKF) has subsequently been developed to deal with measurements of different precisions, namely pseudorange and carrier-phase measurements. This paper proposes a real-time GPS/Galileo PPP system, which employs a modified version of CAKF called the Improved Robust adaptive Kalman Filter (IRKF). The positioning performance of GPS/Galileo PPP through the IRKF is initially verified in comparison with those obtained through the EKF, RKF, and CAKF using the Centre for Orbit Determination in Europe (CODE) final orbit and clock products in both of static and kinematic modes. The real-time GPS/Galileo PPP solution through the IRKF is then assessed in comparison with its near-real-time counterpart. The results indicate that when the IRKF approach is utilised, the positioning accuracy is significantly improved and the convergence behaviour is enhanced compared with results from EKF, conventional RKF, and CAKF. In the real-time mode, centimeter-level horizontal positioning accuracy is achieved under an open sky environment, while decimeter-level horizontal positioning accuracy is achieved under a challenging environment. On the other hand, decimeter-level accuracy is achieved for the vertical positioning component under all environmental scenarios. Moreover, the positioning accuracy of the real-time solution is comparable to the near-real-time counterpart. Numéro de notice : A2021-914 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2020.1846361 Date de publication en ligne : 23/11/2020 En ligne : https://doi.org/10.1080/00396265.2020.1846361 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99317
in Survey review > Vol 53 n° 381 (November 2021) . - pp 528 - 542[article]Estimation and analysis of GPS inter-fequency clock biases from long-term triple-frequency observations / Fan Zhang in GPS solutions, vol 25 n° 4 (October 2021)
[article]
Titre : Estimation and analysis of GPS inter-fequency clock biases from long-term triple-frequency observations Type de document : Article/Communication Auteurs : Fan Zhang, Auteur ; Hongzhou Chai, Auteur ; Linyang Li, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 126 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] décalage d'horloge
[Termes IGN] erreur systématique interfréquence d'horloge
[Termes IGN] fréquence multiple
[Termes IGN] phase GPS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] station GNSS
[Termes IGN] triple différence
[Termes IGN] variation temporelleRésumé : (auteur) Usually, the difference between the satellite clocks computed with L1/L2 and clocks computed with L1/L5 is defined as inter-frequency clock bias (IFCB). It is critical to correct its L5 time-variant portion in the GNSS triple-frequency precise positioning. Using two years of observations from more than 100 stations worldwide, we use the epoch-differenced method to estimate IFCB for all available 12 GPS BLOCK-IIF satellites, and analyze its short-term and long-term variations. The experimental results indicate that the IFCB variations are clearly consistent for two satellites located in the same orbital plane, which perhaps means that the variations of IFCB are dependent on the orbital plane. We found that the IFCB of each Block-IIF satellite shows repetition characteristics over two years. The annual repetition cycle of 352 days of IFCB is consistent with the GPS year 351.4 days may originate from the rotation of satellites around the earth. GPS triple-frequency uncombined PPP is carried out using 9 globally distributed MGEX stations from June 1 to 30, 2018. The experimental results indicate that compared to the PPP solutions without IFCB corrections, GPS triple-frequency PPP can achieve an accuracy of 2.2, 3.8 and 11.4 mm in the north, east, and up components after correcting IFCB, which is an accuracy increase in 31.3%, 17.4%, and 13.0%, respectively. The average RMS of the phase posteriori residuals for each frequency is also reduced significantly, especially 79.1% for L5 frequency. Numéro de notice : A2021-565 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-021-01161-8 Date de publication en ligne : 10/07/2021 En ligne : https://doi.org/10.1007/s10291-021-01161-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98134
in GPS solutions > vol 25 n° 4 (October 2021) . - n° 126[article]Non-tidal loading of the Baltic Sea in Latvian GNSS time series / Diana Haritonova in Journal of applied geodesy, vol 15 n° 4 (October 2021)
[article]
Titre : Non-tidal loading of the Baltic Sea in Latvian GNSS time series Type de document : Article/Communication Auteurs : Diana Haritonova, Auteur Année de publication : 2021 Article en page(s) : pp 293 - 304 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] Baltique, mer
[Termes IGN] coefficient de corrélation
[Termes IGN] Continuously Operating Reference Station network
[Termes IGN] données GNSS
[Termes IGN] effet de charge
[Termes IGN] Lettonie
[Termes IGN] marégraphe
[Termes IGN] niveau de la mer
[Termes IGN] série temporelle
[Termes IGN] station de référence
[Termes IGN] surcharge océaniqueRésumé : (auteur) The objective of this study is to investigate the effect of the Baltic Sea non-tidal loading in the territory of Latvia using observations of the GNSS continuously operating reference stations (CORS) of LatPos, EUPOS®-Riga, EPN and EstPos networks. The GNSS station daily coordinate time series obtained in a double-difference (DD) mode were used. For representation of the sea level dynamics, the Latvian tide gauge records were used. Performed correlation analysis is based on yearly data sets of these observations for the period from 2012 up to 2020. The approach discloses how the non-tidal loading can induce variations in the time series of the regional GNSS station network. This paper increases understanding of the Earth’s surface displacements occurring due to the non-tidal loading effect in Latvia, and is intended to raise the importance and necessity of improved Latvian GNSS time series by removing loading effects. Numéro de notice : A2021-750 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2021-0024 Date de publication en ligne : 23/06/2021 En ligne : https://doi.org/10.1515/jag-2021-0024 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98719
in Journal of applied geodesy > vol 15 n° 4 (October 2021) . - pp 293 - 304[article]On the TEC bias of altimeter satellites / Francisco Azpilicueta in Journal of geodesy, vol 95 n° 10 (October 2021)
[article]
Titre : On the TEC bias of altimeter satellites Type de document : Article/Communication Auteurs : Francisco Azpilicueta, Auteur ; Bruno Nava, Auteur Année de publication : 2021 Article en page(s) : n° 114 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] altimétrie satellitaire par radar
[Termes IGN] données DORIS
[Termes IGN] données Jason
[Termes IGN] données Topex-Poseidon
[Termes IGN] erreur systématique
[Termes IGN] teneur totale en électrons
[Termes IGN] traitement de données GNSSRésumé : (auteur) TOPEX/Poseidon, Jason-1, Jason-2 and Jason-3 altimeter missions have provided 27 + years of uninterrupted Total Electron Content (TEC) measurements since 1992, with unprecedented precision. Nevertheless, the issue of a possible systematic bias in the data was identified immediately after first TOPEX measurements were compared with measurements from other sources. The bias issue has remained open for decades, and it has increased in complexity because each new mission had its different bias. The purpose of this paper is to assess the problem of TEC bias of altimeters. Two approaches have been followed. The first one relied on the TEC data series of the four altimeters to determine inter-mission systematic biases using the last available data versions for each mission. The second approach consisted of inspecting the missions’ official reports to trace changes of the inter-mission and inter-version biases, including biases relative to DORIS ionospheric measurements. Both approaches have converged and resulted in the determination of a reference frame where missions, instruments and ionospheric reference levels could be compared. This reference frame was also used to analyze results published in representative papers during the last decades, including ionospheric data from the ENVISAT mission. This reference frame could help to assess TEC levels of the announced new data version of Jason-2, Jason-3 and the imminent Jason-CS/Sentinel missions. The main conclusion of this work is that Jason-1, ‘E’ data version, defines a TEC reference level which is compatible with most of the results found in the literature. Numéro de notice : A2021-747 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-021-01564-y Date de publication en ligne : 04/10/2021 En ligne : https://doi.org/10.1007/s00190-021-01564-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98706
in Journal of geodesy > vol 95 n° 10 (October 2021) . - n° 114[article]Performance investigation of LAMBDA and bootstrapping methods for PPP narrow-lane ambiguity resolution / Omer Faruk Atiz in Geo-spatial Information Science, vol 24 n° 4 (October 2021)PermalinkPredicting total electron content in ionosphere using vector autoregression model during geomagnetic storm / Sumitra Iyer in Journal of applied geodesy, vol 15 n° 4 (October 2021)PermalinkA constrained extended Kalman filter based on LS-VCE formulated by condition equations with prediction of cross-covariances / Vahid Mahboub in Survey review, Vol 53 n° 380 (September 2021)PermalinkInfluence of aperiodic non-tidal atmospheric and oceanic loading deformations on the stochastic properties of global GNSS vertical land motion time series / Kevin Gobron in Journal of geophysical research : Solid Earth, vol 126 n° 9 (September 2021)PermalinkA new approach for the development of grid models calculating tropospheric key parameters over China / Ge Zhu in Remote sensing, vol 13 n° 17 (September-1 2021)PermalinkTropospheric and range biases in Satellite Laser Ranging / Mateusz Drożdżewski in Journal of geodesy, vol 95 n° 9 (September 2021)PermalinkVectorial integer bootstrapping: flexible integer estimation with application to GNSS / Peter J.G. Teunissen in Journal of geodesy, vol 95 n° 9 (September 2021)PermalinkGPS satellite differential code bias estimation with current eleven low earth orbit satellites / Xingxing Li in Journal of geodesy, vol 95 n° 7 (July 2021)PermalinkComparison of polar ionospheric behavior at Arctic and Antarctic regions for improved satellite-based positioning / Arun Kumar Singh in Journal of applied geodesy, vol 15 n° 3 (July 2021)PermalinkIonospheric irregularity layer height and thickness estimation with a GNSS receiver array / Seebany Datta-Barua in IEEE Transactions on geoscience and remote sensing, Vol 59 n° 7 (July 2021)PermalinkBias in least-squares adjustment of implicit functional models / Michael Lösler in Survey review, Vol 53 n° 378 (May 2021)PermalinkObservable quality assessment of broadband very long baseline interferometry system / Ming H. Xu in Journal of geodesy, vol 95 n° 5 (May 2021)PermalinkInteger phase clock method with single-satellite ambiguity fixing and its application in LEO satellite orbit determination / Kai Shao in Acta Geodaetica et Cartographica Sinica, vol 50 n° 4 ([20/04/2021])PermalinkImpact of the third frequency GNSS pseudorange and carrier phase observations on rapid PPP convergences / Jiang Guo in GPS solutions, vol 25 n° 2 (April 2021)PermalinkMulti-GNSS real-time precise clock estimation considering the correction of inter-satellite code biases / Liang Chen in GPS solutions, vol 25 n° 2 (April 2021)PermalinkApplication of a multi-layer artificial neural network in a 3-D global electron density model using the long-term observations of COSMIC, Fengyun-3C, and Digisonde / Li Wang in Space weather, vol 19 n° 3 (March 2021)PermalinkIntegrity investigation of global ionospheric TEC maps for high-precision positioning / Jiaojiao Zhao in Journal of geodesy, vol 95 n° 3 (March 2021)PermalinkMitigating high latitude ionospheric scintillation effects on GNSS Precise Point Positioning exploiting 1-s scintillation indices / Kai Guo in Journal of geodesy, vol 95 n° 3 (March 2021)PermalinkON GLONASS pseudo-range inter-frequency bias solution with ionospheric delay modeling and the undifferenced uncombined PPP / Zheng Zhang in Journal of geodesy, vol 95 n° 3 (March 2021)PermalinkThe Realization and evaluation of PPP ambiguity resolution with INS aiding in marine survey / Zhenqiang Du in Marine geodesy, vol 44 n° 2 (March 2021)Permalink