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Application of SWACI products as ionospheric correction for single-point positioning: a comparative study / David Minkwitz in Journal of geodesy, vol 88 n° 5 (May 2014)
[article]
Titre : Application of SWACI products as ionospheric correction for single-point positioning: a comparative study Type de document : Article/Communication Auteurs : David Minkwitz, Auteur ; Tajana Gerzen, Auteur ; Volker Wilken, Auteur ; Norbert Jakowski, Auteur Année de publication : 2014 Article en page(s) : pp 463 - 478 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse comparative
[Termes IGN] correction ionosphérique
[Termes IGN] dégradation du signal
[Termes IGN] ionosphère
[Termes IGN] positionnement par GNSS
[Termes IGN] précision du positionnement
[Termes IGN] teneur totale en électrons
[Termes IGN] traitement de données GNSSRésumé : (Auteur) In Global Navigation Satellite Systems (GNSS) using L-band frequencies, the ionosphere causes signal delays that correspond with link related range errors of up to 100 m. In a first order approximation the range error is proportional to the total electron content (TEC) of the ionosphere. Whereas this first order range error can be corrected in dual-frequency measurements by a linear combination of carrier phase- or code-ranges of both frequencies, single-frequency users need additional information to mitigate the ionospheric error. This information can be provided by TEC maps deduced from corresponding GNSS measurements or by ionospheric models. In this paper we discuss and compare different ionospheric correction methods for single-frequency users. The focus is on the comparison of the positioning quality using dual-frequency measurements, the Klobuchar model, the NeQuick model, the IGS TEC maps, the Neustrelitz TEC Model (NTCM-GL) and the reconstructed NTCM-GL TEC maps both provided via the ionosphere data service SWACI (http://swaciweb.dlr.de) in near real-time. For that purpose, data from different locations covering several days in 2011 and 2012 are investigated, including periods of quiet and disturbed ionospheric conditions. In applying the NTCM-GL based corrections instead of the Klobuchar model, positioning accuracy improvements up to several meters have been found for the European region in dependence on the ionospheric conditions. Further in mid- and low-latitudes the NTCM-GL model provides results comparable to NeQuick during the considered time periods. Moreover, in regions with a dense GNSS ground station network the reconstructed NTCM-GL TEC maps are partly at the same level as the final IGS TEC maps. Numéro de notice : A2014-255 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0698-8 Date de publication en ligne : 21/02/2014 En ligne : https://doi.org/10.1007/s00190-014-0698-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33158
in Journal of geodesy > vol 88 n° 5 (May 2014) . - pp 463 - 478[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2014051 SL Revue Centre de documentation Revues en salle Disponible Comparisons of atmospheric mass variations derived from ECMWF reanalysis and operational fields, over 2003–2011 / E. Forootan in Journal of geodesy, vol 88 n° 5 (May 2014)
[article]
Titre : Comparisons of atmospheric mass variations derived from ECMWF reanalysis and operational fields, over 2003–2011 Type de document : Article/Communication Auteurs : E. Forootan, Auteur ; Olga Didova, Auteur ; M. Schumacher, Auteur ; J. Kusche, Auteur ; B. Elsaka, Auteur Année de publication : 2014 Article en page(s) : pp 503 - 514 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] analyse comparative
[Termes IGN] analyse diachronique
[Termes IGN] atmosphère terrestre
[Termes IGN] données GRACE
[Termes IGN] levé gravimétrique
[Termes IGN] masse d'air
[Termes IGN] variationRésumé : (Auteur) There are two spurious jumps in the atmospheric part of the Gravity Recovery and Climate Experiment-Atmosphere and Ocean De-aliasing level 1B (GRACE-AOD1B) products, which occurred in January-February of the years 2006 and 2010, as a result of the vertical level and horizontal resolution changes in the ECMWFop (European Centre for Medium-Range Weather Forecasts operational analysis). These jumps cause a systematic error in the estimation of mass changes from GRACE time-variable level 2 products, since GRACE-AOD1B mass variations are removed during the computation of GRACE level 2. In this short note, the potential impact of using an improved set of 6-hourly atmospheric de-aliasing products on the computations of linear trends as well as the amplitude of annual and semi-annual mass changes from GRACE is assessed. These improvements result from 1) employing a modified 3D integration approach (ITG3D), and 2) using long-term consistent atmospheric fields from the ECMWF reanalysis (ERA-Interim). The monthly averages of the new ITG3D-ERA-Interim de-aliasing products are then compared to the atmospheric part of GRACE-AOD1B, covering January 2003 to December 2010. These comparisons include the 33 world largest river basins along with Greenland and Antarctica ice sheets. The results indicate a considerable difference in total atmospheric mass derived from the two products over some of the mentioned regions. We suggest that future GRACE studies consider these through updating uncertainty budgets or by applying corrections to estimated trends and amplitudes/phases Numéro de notice : A2014-258 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0696-x Date de publication en ligne : 07/02/2014 En ligne : https://doi.org/10.1007/s00190-014-0696-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33161
in Journal of geodesy > vol 88 n° 5 (May 2014) . - pp 503 - 514[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2014051 SL Revue Centre de documentation Revues en salle Disponible Climatological study of ionospheric irregularities over the European mid-latitude sector with GPS / Gilles Wautelet in Journal of geodesy, vol 88 n° 3 (March 2014)
[article]
Titre : Climatological study of ionospheric irregularities over the European mid-latitude sector with GPS Type de document : Article/Communication Auteurs : Gilles Wautelet, Auteur ; René Warnant, Auteur Année de publication : 2014 Article en page(s) : pp 223 - 240 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] analyse diachronique
[Termes IGN] Belgique
[Termes IGN] données GPS
[Termes IGN] Europe (géographie politique)
[Termes IGN] perturbation ionosphérique
[Termes IGN] teneur totale en électrons
[Termes IGN] variation
[Termes IGN] variation temporelleRésumé : (Auteur) High-frequency variability of the ionosphere, or irregularities, constitutes the main threat for real-time precise positioning techniques based on Global Navigation Satellite Systems (GNSS) measurements. Indeed, during periods of enhanced ionospheric variability, GNSS users in the field—who cannot verify the integrity of their measurements—will experience positioning errors that can reach several decimeters, while the nominal accuracy of the technique is cm-level. In the frame of this paper, a climatological analysis of irregularities over the European mid-latitude region is presented. Based on a 10 years GPS dataset over Belgium, the work analyzes the occurrence rate (as a function of the solar cycle, season and local time) as well as the amplitude of ionospheric irregularities observed at a single GPS station. The study covers irregularities either due to space weather events (solar origin) or of terrestrial origin. If space weather irregularities are responsible for the largest effects in terms of ionospheric error, their occurrence rate highly depends on solar activity. Indeed, the occurrence rate of ionospheric irregularities is about 9 % during solar maximum, whereas it drops to about 0 % during medium or low solar activity periods. Medium-scale ionospheric disturbances (MSTIDs) occurring during daytime in autumn/winter are the most recurrent pattern of the time series, with yearly proportions slightly varying with the solar cycle and an amplitude of about 10 % of the TEC background. Another recurrent irregularity type, though less frequent than MSTIDs, is the noise-like variability in TEC observed during summer nighttime, under quiet geomagnetic conditions. These summer nighttime irregularities exhibit amplitudes ranging between 8 and 15 % of the TEC background. Numéro de notice : A2014-133 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-013-0678-4 Date de publication en ligne : 11/12/2013 En ligne : https://doi.org/10.1007/s00190-013-0678-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33038
in Journal of geodesy > vol 88 n° 3 (March 2014) . - pp 223 - 240[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2014031 SL Revue Centre de documentation Revues en salle Disponible GNSS ambiguity resolution with controllable failure rate for long baseline network RTK / Bofeng Li in Journal of geodesy, vol 88 n° 2 (February 2014)
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Titre : GNSS ambiguity resolution with controllable failure rate for long baseline network RTK Type de document : Article/Communication Auteurs : Bofeng Li, Auteur ; Yunzhong Shen, Auteur ; Yanming Feng, Auteur ; et al., Auteur Année de publication : 2014 Article en page(s) : pp 99 - 112 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Continuously Operating Reference Station network
[Termes IGN] filtre de Kalman
[Termes IGN] modèle ionosphérique
[Termes IGN] perturbation ionosphérique
[Termes IGN] résolution d'ambiguïté
[Termes IGN] station de référence
[Termes IGN] traitement de données GNSS
[Vedettes matières IGN] Traitement de données GNSSRésumé : (Auteur) Many large-scale GNSS CORS networks have been deployed around the world to support various commercial and scientific applications. To make use of these networks for real-time kinematic positioning services, one of the major challenges is the ambiguity resolution (AR) over long inter-station baselines in the presence of considerable atmosphere biases. Usually, the widelane ambiguities are fixed first, followed by the procedure of determination of the narrowlane ambiguity integers based on the ionosphere-free model in which the widelane integers are introduced as known quantities. This paper seeks to improve the AR performance over long baseline through efficient procedures for improved float solutions and ambiguity fixing. The contribution is threefold: (1) instead of using the ionosphere-free measurements, the absolute and/or relative ionospheric constraints are introduced in the ionosphere-constrained model to enhance the model strength, thus resulting in the better float solutions; (2) the realistic widelane ambiguity precision is estimated by capturing the multipath effects due to the observation complexity, leading to improvement of reliability of widelane AR; (3) for the narrowlane AR, the partial AR for a subset of ambiguities selected according to the successively increased elevation is applied. For fixing the scalar ambiguity, an error probability controllable rounding method is proposed. The established ionosphere-constrained model can be efficiently solved based on the sequential Kalman filter. It can be either reduced to some special models simply by adjusting the variances of ionospheric constraints, or extended with more parameters and constraints. The presented methodology is tested over seven baselines of around 100 km from USA CORS network. The results show that the new widelane AR scheme can obtain the 99.4 % successful fixing rate with 0.6 % failure rate; while the new rounding method of narrowlane AR can obtain the fix rate of 89 % with failure rate of 0.8 %. In summary, the AR reliability can be efficiently improved with rigorous controllable probability of incorrectly fixed ambiguities. Numéro de notice : A2014-138 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-013-0670-z Date de publication en ligne : 15/11/2013 En ligne : https://doi.org/10.1007/s00190-013-0670-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33043
in Journal of geodesy > vol 88 n° 2 (February 2014) . - pp 99 - 112[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2014021 SL Revue Centre de documentation Revues en salle Disponible Ionospheric modeling using GPS: Greater fidelity using a 3D approach / Wei Zhang in GPS world, vol 25 n° 2 (February 2014)
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Titre : Ionospheric modeling using GPS: Greater fidelity using a 3D approach Type de document : Article/Communication Auteurs : Wei Zhang, Auteur ; Attila Komjathy, Auteur ; Simon Banville, Auteur ; Richard B. Langley, Auteur Année de publication : 2014 Article en page(s) : pp 59 - 65 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] données localisées 3D
[Termes IGN] fonction orthogonale
[Termes IGN] modèle ionosphérique
[Termes IGN] signal GPS
[Termes IGN] temps réelRésumé : (Auteur) In this month's column, we look at the performance of this 3D approach to modeling the ionosphere including times when the ionosphere is particularly interesting. Numéro de notice : A2014-096 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33001
in GPS world > vol 25 n° 2 (February 2014) . - pp 59 - 65[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 067-2014021 RAB Revue Centre de documentation En réserve L003 Disponible Modeling and sensing the vertical structure of the atmospheric path delay by microwave radiometry to correct SAR interferograms / Patrizia Basili in IEEE Transactions on geoscience and remote sensing, vol 52 n° 2 (February 2014)PermalinkAtmospheric water vapour sensing by means of differential absorption spectrometry using solar and lunar radiation / Stefan Walter Münch (2014)PermalinkDORIS tropospheric estimation at IGN : Current strategies, GPS intercomparisons and perspectives / Pascal Willis (2014)PermalinkPermalinkModélisation de la propagation troposphérique des signaux de positionnement par satellites : un tour d'horizon / Camille Desjardins (2014)PermalinkUpdating ESA’s Earth System Model for Gravity Mission Simulation Studies, 2. Comparison with the Original Model / I. Bergmann–Wolf (2014)PermalinkPerformance evaluation of USTEC product for single-frequency precise point positioning / Mahmoud Abd-El-Rahman in Geomatica, vol 67 n° 4 (December 2013)PermalinkTroposphere delays from space geodetic techniques, water vapor radiometers, and numerical weather models over a series of continuous VLBI campaigns / Kamil Teke in Journal of geodesy, vol 87 n° 10-12 (October - December 2013)PermalinkA sky status indicator to detect rain-affected atmospheric thermal emissions observed at ground / Ada Vittoria Bosisio in IEEE Transactions on geoscience and remote sensing, vol 51 n° 9 (September 2013)PermalinkA technique for routinely updating the ITU-R database using radio occultation electron density profiles / Claudio Brunini in Journal of geodesy, vol 87 n° 9 (September 2013)PermalinkComparison of IASI water vapour products over complex terrain with COPS campaign data / Guido Masiello in Meteorologische Zeitschrift, vol 22 n° 4 (August 2013)PermalinkHow reliable are citizen-derived scientific data? Assessing the quality of contrail observations made by the general public / Amy Fowler in Transactions in GIS, vol 17 n° 4 (August 2013)PermalinkAre numerical weather model outputs helpful to reduce tropospheric delay signals in InSAR data? / Youhei Kinoshita in Journal of geodesy, vol 87 n° 3 (March 2013)PermalinkMéthodes de travail dans les réseaux GNSS, 3ème partie Méthodes du "statique multi-stations" / Romain Legros in XYZ, n° 134 (mars - mai 2013)PermalinkApport du système de navigation GLONASS à la surveillance de l'ionosphère au dessus de l'Europe / Emilie Pelletier (2013)PermalinkExperimental study on the atmospheric delay based on GPS, SAR Interferometry, and numerical weather model data / P. Mateus in IEEE Transactions on geoscience and remote sensing, vol 51 n° 1 Tome 1 (January 2013)PermalinkGalileo IOV-3 broadcasts E1, E5, E6 signals / Oliver Montenbruck in GPS world, vol 24 n° 1 (January 2013)PermalinkGéosciences / Christian Robert (2013)PermalinkMémo visuel de géologie / Yves Lagabrielle (2013)PermalinkPermalink