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Termes IGN > sciences naturelles > physique > optique > optique physique > radiométrie > rayonnement électromagnétique > propagation ionosphérique
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ERTK: extra-wide-lane RTK of triple-frequency GNSS signals / Bofeng Li in Journal of geodesy, vol 91 n° 9 (September 2017)
[article]
Titre : ERTK: extra-wide-lane RTK of triple-frequency GNSS signals Type de document : Article/Communication Auteurs : Bofeng Li, Auteur ; Zhen Li, Auteur ; Zhiteng Zhang, Auteur ; Yu’an Tan, Auteur Année de publication : 2017 Article en page(s) : pp 1031 – 1047 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse comparative
[Termes IGN] données BeiDou
[Termes IGN] données Galileo
[Termes IGN] filtrage du signal
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] précision centimétrique
[Termes IGN] propagation ionosphérique
[Termes IGN] récepteur trifréquence
[Termes IGN] résolution d'ambiguïté
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) Triple-frequency signals have thus far been available for all satellites of BeiDou and Galileo systems and for some GPS satellites. The main benefit of triple-frequency signals is their formation of extra-wide-lane (EWL) combinations whose ambiguities can be instantaneously fixed for several 10–100 km baselines. Yet, this benefit has not been fully exploited and only used as a constraint for narrow-lane (NL) ambiguity resolution (AR) in most previous studies. In this study, we comprehensively investigate the real-time kinematic (RTK) capabilities of EWL observations, also referred to as EWL RTK (ERTK). We begin by mathematically expressing the ease of EWL AR and the difficulty of NL AR, respectively, using a numerical demonstration. We then present the mathematical models for ERTK including the ionosphere-ignored, ionosphere-float and ionosphere-smoothed types. The experiments are conducted using a four-station network of real triple-frequency BeiDou data with baseline lengths from 33 to 75 km. The results show that the ionosphere-ignored ERTK achieves real-time solutions with a horizontal accuracy of about 10 cm. Although the ionosphere-float ERTK solutions are very noisy, they can be quickly improved at the centimetre level by further applying the ionosphere-smoothed model. Note that such accurate results are very promising and already satisfy many applications without complicated NL AR. To the best of our knowledge, this is the first comprehensive study to make full use of EWL observations of triple-frequency signals on RTK. Numéro de notice : A2017-464 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1006-1 En ligne : https://doi.org/10.1007/s00190-017-1006-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86410
in Journal of geodesy > vol 91 n° 9 (September 2017) . - pp 1031 – 1047[article]Performance 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)
[article]
Titre : Performance evaluation of ionospheric time delay forecasting models using GPS observations at a low-latitude station Type de document : Article/Communication Auteurs : G. Sivavaraprasad, Auteur ; D. Venkata Ratman, Auteur Année de publication : 2017 Article en page(s) : pp 475 - 490 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] données GPS
[Termes IGN] données météorologiques
[Termes IGN] Inde
[Termes IGN] International Reference Ionosphere
[Termes IGN] latitude
[Termes IGN] modèle de simulation
[Termes IGN] modèle ionosphérique
[Termes IGN] retard ionosphèrique
[Termes IGN] teneur totale en électrons
[Termes IGN] teneur verticale totale en électrons
[Termes IGN] test de performance
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) Ionospheric delay is one of the major atmospheric effects on the performance of satellite-based radio navigation systems. It limits the accuracy and availability of Global Positioning System (GPS) measurements, related to critical societal and safety applications. The temporal and spatial gradients of ionospheric total electron content (TEC) are driven by several unknown priori geophysical conditions and solar-terrestrial phenomena. Thereby, the prediction of ionospheric delay is challenging especially over Indian sub-continent. Therefore, an appropriate short/long-term ionospheric delay forecasting model is necessary. Hence, the intent of this paper is to forecast ionospheric delays by considering day to day, monthly and seasonal ionospheric TEC variations. GPS-TEC data (January 2013–December 2013) is extracted from a multi frequency GPS receiver established at K L University, Vaddeswaram, Guntur station (geographic: 16.37°N, 80.37°E; geomagnetic: 7.44°N, 153.75°E), India. An evaluation, in terms of forecasting capabilities, of three ionospheric time delay models – an Auto Regressive Moving Average (ARMA) model, Auto Regressive Integrated Moving Average (ARIMA) model, and a Holt-Winter's model is presented. The performances of these models are evaluated through error measurement analysis during both geomagnetic quiet and disturbed days. It is found that, ARMA model is effectively forecasting the ionospheric delay with an accuracy of 82–94%, which is 10% more superior to ARIMA and Holt-Winter’s models. Moreover, the modeled VTEC derived from International Reference Ionosphere, IRI (IRI-2012) model and new global TEC model, Neustrelitz TEC Model (NTCM-GL) have compared with forecasted VTEC values of ARMA, ARIMA and Holt-Winter’s models during geomagnetic quiet days. The forecast results are indicating that ARMA model would be useful to set up an early warning system for ionospheric disturbances at low latitude regions. Numéro de notice : A2017-252 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2017.01.031 Date de publication en ligne : 30/01/2017 En ligne : https://doi.org/10.1016/j.asr.2017.01.031 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85254
in Advances in space research > vol 60 n° 2 (15 July 2017) . - pp 475 - 490[article]Impact of GPS differential code bias in dual- and triple-frequency positioning and satellite clock estimation / Haojun Li in GPS solutions, vol 21 n° 3 (July 2017)
[article]
Titre : Impact of GPS differential code bias in dual- and triple-frequency positioning and satellite clock estimation Type de document : Article/Communication Auteurs : Haojun Li, Auteur ; Bofeng Li, Auteur ; Lizhi Lou, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 897 – 903 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] code GPS
[Termes IGN] erreur corrélée au temps
[Termes IGN] erreur systématique
[Termes IGN] géodésie spatiale
[Termes IGN] GPS en mode différentiel
[Termes IGN] positionnement ponctuel précis
[Termes IGN] récepteur bifréquence
[Termes IGN] récepteur trifréquence
[Termes IGN] retard ionosphèriqueRésumé : (auteur) The features and differences of various GPS differential code bias (DCB)s are discussed. The application of these biases in dual- and triple-frequency satellite clock estimation is introduced based on this discussion. A method for estimating the satellite clock error from triple-frequency uncombined observations is presented to meet the need of the triple-frequency uncombined precise point positioning (PPP). In order to evaluate the estimated satellite clock error, the performance of these biases in dual- and triple-frequency positioning is studied. Analysis of the inter-frequency clock bias (IFCB), which is a result of constant and time-varying frequency-dependent hardware delays, in ionospheric-free code-based (P1/P5) single point positioning indicates that its influence on the up direction is more pronounced than on the north and east directions. When the IFCB is corrected, the mean improvements are about 29, 35 and 52% for north, east and up directions, respectively. Considering the contribution of code observations to PPP convergence time, the performance of DCB(P1–P2), DCB(P1–P5) and IFCB in GPS triple-frequency PPP convergence is investigated. The results indicate that the DCB correction can accelerate PPP convergence by means of improving the accuracy of the code observation. The performance of these biases in positioning further verifies the correctness of the estimated dual- and triple-frequency satellite clock error. Numéro de notice : A2017-441 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-016-0578-1 En ligne : https://doi.org/10.1007/s10291-016-0578-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86358
in GPS solutions > vol 21 n° 3 (July 2017) . - pp 897 – 903[article]Automatic GPS ionospheric amplitude and phase scintillation detectors using a machine learning algorithm / Yu Jiao in Inside GNSS, vol 12 n° 3 (May - June 2017)
[article]
Titre : Automatic GPS ionospheric amplitude and phase scintillation detectors using a machine learning algorithm Type de document : Article/Communication Auteurs : Yu Jiao, Auteur ; John J. Hall, Auteur ; Yu T. Morton, Auteur Année de publication : 2017 Article en page(s) : pp 48 - 54 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] amplitude
[Termes IGN] apprentissage automatique
[Termes IGN] détecteur
[Termes IGN] propagation ionosphérique
[Termes IGN] scintillationRésumé : (auteur) Ionospheric scintillation can cause errors or outage in GNSS services. Timely detection of ionospheric scintillation will enable adaptive processing to mitigate its effects on navigation solutions. This article presents a machine learning algorithm to autonomously detect ionospheric amplitude and phase scintillation. Systematic validations of the algorithm show the accuracies of amplitude and phase scintillation detections to be at around 98% and 92%, respectively. Tests were also conducted using data from locations not involved in training process and the results demonstrate the generalization capabilities of the scintillation detectors. In addition, concurrent amplitude and phase scintillation detection using similar machine learning algorithms is further investigated with low-latitude scintillation data. Our findings suggest that at low latitudes, amplitude detector alone is sufficient to capture scintillation in general. At high latitudes, phase scintillation is known to be the dominating phenomena and phase scintillation detector is necessary to capture the scintillation events. Numéro de notice : A2017-259 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans En ligne : http://www.insidegnss.com/node/5467 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85276
in Inside GNSS > vol 12 n° 3 (May - June 2017) . - pp 48 - 54[article]On the determination of the effect of horizontal ionospheric gradients on ranging errors in GNSS positioning / Ekaterina A. Danilogorskaya in Journal of geodesy, vol 91 n° 5 (May 2017)
[article]
Titre : On the determination of the effect of horizontal ionospheric gradients on ranging errors in GNSS positioning Type de document : Article/Communication Auteurs : Ekaterina A. Danilogorskaya, Auteur ; Nikolay N. Zernov, Auteur ; Vadim E. Gherm, Auteur ; Hal J. Strangeways, Auteur Année de publication : 2017 Article en page(s) : pp 503 – 517 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] données GNSS
[Termes IGN] gradient
[Termes IGN] propagation ionosphérique
[Termes IGN] teneur totale en électronsRésumé : (auteur) An alternative approach to the traditionally employed method is proposed for treating the ionospheric range errors in transionospheric propagation such as for GNSS positioning or satellite-borne SAR. It enables the effects due to horizontal gradients of electron density (as well as vertical gradients) in the ionosphere to be explicitly accounted for. By contrast with many previous treatments, where the expansion of the solution for the phase advance is represented as the series in the inverse frequency powers and the main term of the expansion corresponds to the true line-of-sight distance from the transmitter to the receiver, in the alternative technique the zero-order term is the rigorous solution for a spherically layered ionosphere with any given vertical electron density profile. The first-order term represents the effects due to the horizontal gradients of the electron density of the ionosphere, and the second-order correction appears to be negligibly small for any reasonable parameters of the path of propagation and its geometry for VHF/UHF frequencies. Additionally, an “effective” spherically symmetric model of the ionosphere has been introduced, which accounts for the major contribution of the horizontal gradients of the ionosphere and provides very high accuracy in calculations of the phase advance. Numéro de notice : A2017-226 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0978-6 En ligne : http://dx.doi.org/10.1007/s00190-016-0978-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85107
in Journal of geodesy > vol 91 n° 5 (May 2017) . - pp 503 – 517[article]An examination of the Galileo NeQuick model: comparison with GPS and JASON TEC / Ningbo Wang in GPS solutions, vol 21 n° 2 (April 2017)PermalinkFast ambiguity resolution for long-range reference station networks with ionospheric model constraint method / Ming Zhang in GPS solutions, vol 21 n° 2 (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)PermalinkIonospheric tomography based on GNSS observations of the CMONOC: performance in the topside ionosphere / Zhe Yang in GPS solutions, vol 21 n° 2 (April 2017)PermalinkAssessment of second- and third-order ionospheric effects on regional networks : case study in China with longer CMONOC GPS coordinate time series / Liansheng Deng in Journal of geodesy, vol 91 n° 2 (February 2017)PermalinkPermalinkEvaluation of GPS standard point positioning with various ionospheric error mitigation techniques / Sampad K. Panda in Journal of applied geodesy, vol 10 n° 4 (December 2016)PermalinkVariations of total electron content over Serbia during the increased solar activity period in 2013 and 2014 / Dragan Blagojevic in Geodetski vestnik, vol 60 n° 4 (December 2016)PermalinkGalileo cycle-slip detection : How four frequencies help when the ionosphere is disturbed / Laura Van de Vyver in GPS world, vol 27 n° 9 (September 2016)PermalinkAtmospheric correction in time-series SAR interferometry for land surface deformation mapping : A case study of Taiyuan, China / Wei Tang in Advances in space research, vol 58 n° 3 (August 2016)Permalink