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The ionosphere : effects, GPS modeling and the benefits for space geodetic techniques / Manuel Hernández-Pajares in Journal of geodesy, vol 85 n° 12 (December 2011)
[article]
Titre : The ionosphere : effects, GPS modeling and the benefits for space geodetic techniques Type de document : Article/Communication Auteurs : Manuel Hernández-Pajares, Auteur ; M. Juan, Auteur ; Jaume Sanz, Auteur ; et al., Auteur Année de publication : 2011 Article en page(s) : pp 887 - 907 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] données GNSS
[Termes IGN] données GPS
[Termes IGN] ionosphère
[Termes IGN] modèle ionosphérique
[Termes IGN] perturbation ionosphérique
[Termes IGN] propagation du signal
[Termes IGN] qualité du signal
[Termes IGN] signal GNSS
[Termes IGN] signal GPS
[Termes IGN] surveillance
[Termes IGN] teneur totale en électronsRésumé : (Auteur) The main goal of this paper is to provide a summary of our current knowledge of the ionosphere as it relates to space geodetic techniques, especially the most informative technology, global navigation satellite systems (GNSS), specifically the fully deployed and operational global positioning system (GPS). As such, the main relevant modeling points are discussed, and the corresponding results of ionospheric monitoring are related, which were mostly computed using GPS data and based on the direct experience of the authors. We address various phenomena such as horizontal and vertical ionospheric morphology in quiet conditions, traveling ionospheric disturbances, solar flares, ionospheric storms and scintillation. Finally, we also tackle the question of how improved knowledge of ionospheric conditions, especially in terms of an accurate understanding of the distribution of free electrons, can improve space geodetic techniques at different levels, such as higher-order ionospheric effects, precise GNSS navigation, single-antenna GNSS orientation and real-time GNSS meteorology. Numéro de notice : A2011-501 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-011-0508-5 Date de publication en ligne : 11/09/2011 En ligne : https://doi.org/10.1007/s00190-011-0508-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31395
in Journal of geodesy > vol 85 n° 12 (December 2011) . - pp 887 - 907[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2011121 RAB Revue Centre de documentation En réserve L003 Disponible Validation of international reference ionosphere models using in situ measurements from GRACE K-band ranging system and CHAMP planar Langmuir probe / C. Lee in Journal of geodesy, vol 85 n° 12 (December 2011)
[article]
Titre : Validation of international reference ionosphere models using in situ measurements from GRACE K-band ranging system and CHAMP planar Langmuir probe Type de document : Article/Communication Auteurs : C. Lee, Auteur ; S. Han, Auteur ; Dieter Bilitza, Auteur ; J. Chung, Auteur Année de publication : 2011 Article en page(s) : pp 921 - 929 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse comparative
[Termes IGN] analyse diachronique
[Termes IGN] atmosphère solaire
[Termes IGN] bande K
[Termes IGN] données CHAMP
[Termes IGN] données GRACE
[Termes IGN] International Reference Ionosphere
[Termes IGN] modèle ionosphérique
[Termes IGN] teneur totale en électrons
[Termes IGN] zone équatoriale
[Termes IGN] zone polaireRésumé : (Auteur) The in situ measurements of electron contents from GRACE K-band (dual-frequency) ranging system and CHAMP planar Langmuir probe were used to validate the international reference ionosphere (IRI) models. The comparison using measurements from year 2003 to 2007 shows a general agreement between data and the model outputs. The improvement in the newer IRI model (IRI-2007) is evident with the measurements from the GRACE satellites orbiting at the higher altitude. We present the comparison between the models and data comprehensively for various cases in solar activity, local time, season, and latitude. The IRI models do not well predict the electron density in the years 2006 and later, when the solar activity is extremely low. The IRI models generally overestimate the electron density during local winter while they underestimate during local summer. In the equatorial region, the large difference at local sunrise lasts for all years and all seasons. The IRI models do not perform well in predicting the anomaly in the polar region such as the Weddell Sea Anomaly. These discrepancies are likely due to smoothed (12-month averaged) solar activity indices used in the IRI models and due to insufficient spherical harmonic representation not able to capture small spatial scales. In near future, further improvement on the IRI models is expected by assimilating those in situ satellite data by implementing higher resolution (spatial and temporal) parameterizations. Numéro de notice : A2011-503 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-011-0442-6 Date de publication en ligne : 30/11/2019 En ligne : https://doi.org/10.1007/s00190-011-0442-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31397
in Journal of geodesy > vol 85 n° 12 (December 2011) . - pp 921 - 929[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2011121 RAB Revue Centre de documentation En réserve L003 Disponible Accuracy assessment of the GPS-TEC calibration constants by means of a simulation technique / Jacques Conte in Journal of geodesy, vol 85 n° 10 (October 2011)
[article]
Titre : Accuracy assessment of the GPS-TEC calibration constants by means of a simulation technique Type de document : Article/Communication Auteurs : Jacques Conte, Auteur ; F. Azpilicueta, Auteur ; C. Brunini, Auteur Année de publication : 2011 Article en page(s) : pp 707 - 714 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] analyse diachronique
[Termes IGN] GPS en mode différentiel
[Termes IGN] ionosphère
[Termes IGN] propagation ionosphérique
[Termes IGN] rayonnement solaire
[Termes IGN] teneur totale en électrons
[Termes IGN] variation saisonnièreRésumé : (Auteur) During the last 2 decades, Global Positioning System (GPS) measurements have become a very important data-source for ionospheric studies. However, it is not a direct and easy task to obtain accurate ionospheric information from these measurements because it is necessary to perform a careful estimation of the calibration constants affecting the GPS observations, the so-called differential code biases (DCBs). In this paper, the most common approximations used in several GPS calibration methods, e.g. the La Plata Ionospheric Model (LPIM), are applied to a set of specially computed synthetic slant Total Electron Content datasets to assess the accuracy of the DCB estimation in a global scale scenario. These synthetic datasets were generated using a modified version of the NeQuick model, and have two important features: they show a realistic temporal and spatial behavior and all a-priori DCBs are set to zero by construction. Then, after the application of the calibration method the deviations from zero of the estimated DCBs are direct indicators of the accuracy of the method. To evaluate the effect of the solar activity radiation level the analysis was performed for years 2001 (high solar activity) and 2006 (low solar activity). To take into account seasonal changes of the ionosphere behavior, the analysis was repeated for three consecutive days close to each equinox and solstice of every year. Then, a data package comprising 24 days from approximately 200 IGS permanent stations was processed. In order to avoid unwanted geomagnetic storms effects, the selected days correspond to periods of quiet geomagnetic conditions. The most important results of this work are: i) the estimated DCBs can be affected by errors around +8 TECu for high solar activity and +3 TECu for low solar activity; and ii) DCB errors present a systematic behavior depending on the modip coordinate, that is more evident for the positive modip region. Numéro de notice : A2011-435 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-011-0477-8 Date de publication en ligne : 15/05/2011 En ligne : https://doi.org/10.1007/s00190-011-0477-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31213
in Journal of geodesy > vol 85 n° 10 (October 2011) . - pp 707 - 714[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2011101 RAB Revue Centre de documentation En réserve L003 Disponible Simulation study of the influence of the ionospheric layer height in the thin layer ionospheric model / C. Brunini in Journal of geodesy, vol 85 n° 9 (September 2011)
[article]
Titre : Simulation study of the influence of the ionospheric layer height in the thin layer ionospheric model Type de document : Article/Communication Auteurs : C. Brunini, Auteur ; E. Camilion, Auteur ; F. Azpilicueta, Auteur Année de publication : 2011 Article en page(s) : pp 637 - 645 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] altitude
[Termes IGN] données GNSS
[Termes IGN] erreur systématique
[Termes IGN] modèle ionosphérique
[Termes IGN] propagation ionosphérique
[Termes IGN] simulation
[Termes IGN] teneur totale en électrons
[Termes IGN] variation saisonnièreRésumé : (Auteur) This work aims to contribute to the understanding of the influence of the ionospheric layer height (ILH) on the thin layer ionospheric model (TLIM) used to retrieve ionospheric information from the GNSS observations. Particular attention is paid to the errors caused on the estimation of the vertical total electron content (vTEC) and the GNSS satellites and receivers inter-frequency biases (IFB), by the use of an inappropriate ILH. The work relies upon numerical simulations performed with an empirical model of the Earth’s ionosphere: the model is used to create realistic but controlled ionospheric scenarios and the errors are evaluated after recovering those scenarios with the TLIM. The error assessment is performed in the Central and the northern part of the South American continents, a region where large errors are expected due to the combined actions of the Appleton Anomaly of the ionosphere and the South-Atlantic anomaly of the geomagnetic field. According to this study, there does not exist a unique ILH that cancels the vTEC error for the whole region under consideration. The ILH that cancels the regional mean vTEC error varies with the solar activity and season. The latitude-dependent conversion error propagates to the parameters of the model used to represent the latitudinal variation on the vTEC on the ionospheric layer, and to the IFB, when these values are simultaneously estimated from the observed sTEC. Besides, the ILH that cancels the regional mean vTEC error is different from the one that cancels the IFB error and the difference between both ILH varies with the solar activity and season. Numéro de notice : A2011-377 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-011-0470-2 Date de publication en ligne : 19/04/2011 En ligne : https://doi.org/10.1007/s00190-011-0470-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31156
in Journal of geodesy > vol 85 n° 9 (September 2011) . - pp 637 - 645[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2011091 RAB Revue Centre de documentation En réserve L003 Disponible GNSS and the Ionosphere: What's in Store for the Next Solar Maximum? / A. Jensen in GPS world, vol 22 n° 2 (February 2011)
[article]
Titre : GNSS and the Ionosphere: What's in Store for the Next Solar Maximum? Type de document : Article/Communication Auteurs : A. Jensen, Auteur ; C. Mitchell, Auteur Année de publication : 2011 Article en page(s) : pp 40 - 48 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] dégradation du signal
[Termes IGN] ionosphère
[Termes IGN] perturbation ionosphérique
[Termes IGN] qualité du signal
[Termes IGN] signal aléatoire
[Termes IGN] signal GNSS
[Termes IGN] vent solaireRésumé : (Editeur) Although the sun can become disturbed at any time, solar activity is correlated with the approximately 11-year cycle of spots on the sun's surface. We are just coming out of a minimum in the solar cycle and headed for the next maximum, predicted to occur around the middle of 2013. How significantly will GNSS users be affected? In this month's column, two ionosphere experts tell us what might be in store. Numéro de notice : A2011-058 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30839
in GPS world > vol 22 n° 2 (February 2011) . - pp 40 - 48[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 067-2011021 RAB Revue Centre de documentation En réserve L003 Disponible Ionospheric response to the geomagnetic storm on august 21, 2003 over China using GNSS-based tomographic technique / D. Wen in IEEE Transactions on geoscience and remote sensing, vol 48 n° 8 (August 2010)PermalinkGPS slant total electron content accuracy using the single layer model under different geomagnetic regions and ionospheric conditions / C. Brunini in Journal of geodesy, vol 84 n° 5 (May 2010)PermalinkWide-area RTK: high precision positioning on a continental scale / Manuel Hernández-Pajares in Inside GNSS, vol 5 n° 2 (March - April 2010)PermalinkImproving the GNSS positioning stochastic model in the presence of ionospheric scintillation / M. Aquino in Journal of geodesy, vol 83 n° 10 (October 2009)PermalinkAccuracy assessment of the GPS-based slant total electron content / C. Brunini in Journal of geodesy, vol 83 n° 8 (August 2009)PermalinkMonitoring storm-enhanced density using IGS reference station data / Anthea Coster in Journal of geodesy, vol 83 n° 3-4 (March - April 2009)Permalinkvol 83 n° 3-4 - March - April 2009 - The International GNSS Service (IGS) in a changing landscape of Global Navigation Satellite Systems (Bulletin de Journal of geodesy) / R. KleesPermalinkPermalinkTsunami detection by GPS: how ionospheric observations might improve the global warning system / Giovanni Occhipinti in GPS world, vol 19 n° 2 (February 2008)PermalinkMulti-dimensional B-spline modeling of spatio-temporal Ionospheric signals / C. Zeilhofer (2008)Permalink