Descripteur
Documents disponibles dans cette catégorie (422)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
Subseasonal GNSS positioning errors / Jim Ray in Geophysical research letters, vol 40 n° 22 (November 2013)
[article]
Titre : Subseasonal GNSS positioning errors Type de document : Article/Communication Auteurs : Jim Ray, Auteur ; Jake Griffiths, Auteur ; Xavier Collilieux , Auteur ; Paul Rebischung , Auteur Année de publication : 2013 Article en page(s) : pp 5854 - 5860 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] bruit rose
[Termes IGN] coordonnées GNSS
[Termes IGN] crénelage
[Termes IGN] données GLONASS
[Termes IGN] élément d'orientation externe
[Termes IGN] variation saisonnière
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) Global Navigation Satellite System (GNSS) station coordinate errors over seasonal and longer time scales are known to be spatially and temporally correlated with flicker noise spectra. Overlaying this are strong annual and semiannual variations that cannot be explained by any single phenomenon. Next most prominent are harmonics of the GPS draconitic year with periods of (351.4/N) days. One explanation is that errors in the standard model for Earth orientation parameter (EOP) tidal variations near 12 and 24 h periods are absorbed into the resonant GPS orbit and daily EOP estimates, resulting mainly in draconitic and fortnightly alias signatures for 24 h product sampling. With the change in International GNSS Service (IGS) station coordinates from weekly to daily resolution in August 2012, it is now possible to study subseasonal performance. All IGS Analysis Centers (ACs) show fortnightly signals, but the resolution will not be sufficient to distinguish direct from aliased subdaily tidal error sources till two more years of data are available. Nevertheless, aliased errors from the subdaily EOP tide model are expected. All but one of the ACs that includes GLONASS data have signals at ~8 day periods, the ground repeat period for GLONASS orbits. This most likely arises from larger geographically correlated orbit errors for GLONASS. Two ACs possess unique short-period features that appear to be caused by peculiarities of their analysis strategies. Numéro de notice : A2013-795 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article DOI : 10.1002/2013GL058160 Date de publication en ligne : 08/11/2013 En ligne : http://dx.doi.org/10.1002/2013GL058160 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80235
in Geophysical research letters > vol 40 n° 22 (November 2013) . - pp 5854 - 5860[article]Documents numériques
en open access
Subseasonal GNSS Positionning ErrorsAdobe Acrobat PDF Monitoring precipitable water vapor in real-time using global navigation satellite systems / Seung-Woo Lee in Journal of geodesy, vol 87 n° 10-12 (October - December 2013)
[article]
Titre : Monitoring precipitable water vapor in real-time using global navigation satellite systems Type de document : Article/Communication Auteurs : Seung-Woo Lee, Auteur ; Jan Kouba, Auteur ; Bob Schutz, Auteur ; et al., Auteur Année de publication : 2013 Article en page(s) : pp 923 - 934 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] analyse diachronique
[Termes IGN] données GNSS
[Termes IGN] précipitation
[Termes IGN] surveillance météorologique
[Termes IGN] temps de propagation
[Termes IGN] temps réel
[Termes IGN] vapeur d'eauRésumé : (Auteur) This paper addresses real-time monitoring of the precipitable water vapor (PWV) from GNSS measurements and presents some results obtained from 6-month long GNSS PWV experiments using international and domestic GNSS networks. In the real-time GNSS PWV monitoring system a server/client structure is employed to facilitate formation of PWV networks and single-differenced GNSS measurements are utilized to mitigate errors in GNSS satellites’ orbits and clocks. An issue relating to baseline length between the server and clients is discussed in detail and as a result the PWV monitor is configured to perform in two modes depending on the baseline length. The server estimates sequentially the zenith wet delay of the individual stations, which is then converted into the PWV of the stations. We evaluate system performance by comparing the real-time PWV solution with reference solutions including meteorological measurements obtained with radiosondes and deferred-time precision GNSS PWV solutions. Results showed that the standard deviation of difference between the real-time PWV and the reference solutions ranged from 2.1 to 3.4 mm in PWV for a 6-month long comparison, which was improved to 1.4 to 2.9 mm by reducing comparison period to 20 days in winter. Numéro de notice : A2013-667 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-013-0655-y Date de publication en ligne : 11/08/2013 En ligne : https://doi.org/10.1007/s00190-013-0655-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32803
in Journal of geodesy > vol 87 n° 10-12 (October - December 2013) . - pp 923 - 934[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 266-2013101 SL Revue Centre de documentation Revues en salle Disponible Troposphere 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)
[article]
Titre : Troposphere delays from space geodetic techniques, water vapor radiometers, and numerical weather models over a series of continuous VLBI campaigns Type de document : Article/Communication Auteurs : Kamil Teke, Auteur ; Tobias Nilsson, Auteur ; Johannes Böhm , Auteur ; Thomas Hobiger, Auteur ; et al., Auteur ; Pascal Willis , Auteur Année de publication : 2013 Article en page(s) : pp 981 - 1001 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] campagne VLBI
[Termes IGN] données DORIS
[Termes IGN] données GNSS
[Termes IGN] données ITGB
[Termes IGN] gradient de troposphère
[Termes IGN] interférométrie à très grande base
[Termes IGN] modèle météorologique
[Termes IGN] propagation troposphérique
[Termes IGN] retard troposphériqueRésumé : (Auteur) Continuous, very long baseline interferometry (VLBI) campaigns over 2 weeks have been carried out repeatedly, i.e., CONT02 in October 2002, CONT05 in September 2005, CONT08 in August 2008, and CONT11 in September 2011, to demonstrate the highest accuracy the current VLBI was capable at that time. In this study, we have compared zenith total delays (ZTD) and troposphere gradients as consistently estimated from the observations of VLBI, Global Navigation Satellite Systems (GNSS), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) at VLBI sites participating in the CONT campaigns. We analyzed the CONT campaigns using the state-of-the-art software following common processing strategies as closely as possible. In parallel, ZTD and gradients were derived from numerical weather models, i.e., from the global European Centre for Medium-Range Weather Forecasts (ECMWF) analysis fields, the High Resolution Limited Area Model (European sites), the Japan Meteorological Agency-Operational Meso-Analysis Field (MANAL, over Japan), and the Cloud Resolving Storm Simulator (Tsukuba, Japan). Finally, zenith wet delays were estimated from the observations of water vapor radiometers (WVR) at sites where the WVR observables are available during the CONT sessions. The best ZTD agreement, interpreted as the smallest standard deviation, was found between GNSS and VLBI techniques to be about 5–6 mm at most of the co-located sites and CONT campaigns. We did not detect any significant improvement in the ZTD agreement between various techniques over time, except for DORIS and MANAL. On the other hand, the agreement and thus the accuracy of the troposphere parameters mainly depend on the amount of humidity in the atmosphere. Numéro de notice : A2013-670 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-013-0662-z Date de publication en ligne : 10/10/2013 En ligne : https://doi.org/10.1007/s00190-013-0662-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32806
in Journal of geodesy > vol 87 n° 10-12 (October - December 2013) . - pp 981 - 1001[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 266-2013101 SL Revue Centre de documentation Revues en salle Disponible Assessing the precision in loading estimates by geodetic techniques in Southern Europe / Pierre Valty in Geophysical journal international, vol 194 n° 3 (September 2013)
[article]
Titre : Assessing the precision in loading estimates by geodetic techniques in Southern Europe Type de document : Article/Communication Auteurs : Pierre Valty , Auteur ; Olivier de Viron, Auteur ; Isabelle Panet , Auteur ; Juliette Legrand, Auteur Année de publication : 2013 Article en page(s) : pp 1441 - 1454 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] déformation verticale de la croute terrestre
[Termes IGN] données GPS
[Termes IGN] données GRACE
[Termes IGN] estimation de précision
[Termes IGN] série temporelle
[Termes IGN] surcharge atmosphérique
[Termes IGN] surcharge océanique
[Termes IGN] varianceRésumé : (auteur) This paper investigates the precision of the estimation of geophysical fluid load deformation computed from GRACE space gravity, GPS vertical displacement and geophysical fluids models [Global Circulation Models (GCMs) for ocean, atmosphere and hydrology], using the three-cornered hat method. This method allows the estimation of the variance of the errors of each technique, when the same quantity is monitored by three instruments with independent errors. Applied on a network of stations, several points of view can be considered: the technique level (in order to determine the error of each technique: GRACE, GPS and GCMs), the solution level (allowing to compare the precision of the same technique when different strategies/models are used), and the station level (in order to emphasize local anomalies and geographical patterns). In particular, our results show a precision of the loading vertical displacement at the level of 1 mm when using GRACE or the fluid models, and of 2 mm using GPS. We do not find significant differences between the precision of different solutions of the same techniques, even when there are strong differences in the data processing. Numéro de notice : A2013-808 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article DOI : 10.1093/gji/ggt173 Date de publication en ligne : 31/05/2013 En ligne : http://dx.doi.org/10.1093/gji/ggt173 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80093
in Geophysical journal international > vol 194 n° 3 (September 2013) . - pp 1441 - 1454[article]Documents numériques
en open access
Assessing the precision in loading estimates ... - pdf éditeurAdobe Acrobat PDF Mapping GPS positional errors using spatial linear mixed models / A.F. Militino in Journal of geodesy, vol 87 n° 7 (July 2013)
[article]
Titre : Mapping GPS positional errors using spatial linear mixed models Type de document : Article/Communication Auteurs : A.F. Militino, Auteur ; M.D. Ugarte, Auteur ; et al., Auteur Année de publication : 2013 Article en page(s) : pp 675 - 685 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] carte thématique
[Termes IGN] données GPS
[Termes IGN] erreur de positionnement
[Termes IGN] estimation statistique
[Termes IGN] modèle linéaire
[Termes IGN] Navarre (Espagne)
[Termes IGN] précision des mesures
[Termes IGN] réseau géodésiqueRésumé : (Auteur) Nowadays, GPS receivers are very reliable because of their good accuracy and precision; however, uncertainty is also inherent in geospatial data. Quality of GPS measurements can be influenced by atmospheric disturbances, multipathing, synchronization of clocks, satellite geometry, geographical features of the observed region, low broadcasting coverage, inadequate transmitting formats, or human or instrumental unknown errors. Assuming that the scenario and technical conditions that can influence the quality of GPS measurements are optimal, that functional and stochastic models that process the signals to a geodetic measurement are correct, and that all the GPS observables are taken in the same conditions, it is still possible to estimate the positional errors as the difference between the real coordinates and those measured by the GPS. In this paper, three spatial linear mixed models, one for each axis, are used for modelling real-time kinematic GPS accuracy and precision, of a multiple-reference-station network in dual-frequency with carrier phase measurements. Along the paper, the proposed models provide an estimate of the “accuracy” in terms of bias defined as the difference between real coordinates and measured coordinates after being processed and “precision” through the standard errors of the estimated differences. This is done using ten different transmitting formats. Mapping and quantifying these differences can be interesting for users and GPS professionals. The performance of these models is illustrated by mapping positional error estimates within the whole region of Navarre, Spain. Sampled data have been taken in 54 out of the 211 geodetic vertex points of this region. Maps show interesting error patterns depending on transmitting formats, the different axes, and the geographical characteristics of the region. Higher differences are found in regions with bad broadcasting coverage, due to the presence of mountains and high degree of humidity. Numéro de notice : A2013-401 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-013-0638-z Date de publication en ligne : 03/09/2013 En ligne : https://doi.org/10.1007/s00190-013-0638-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32539
in Journal of geodesy > vol 87 n° 7 (July 2013) . - pp 675 - 685[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 266-2013071 SL Revue Centre de documentation Revues en salle Disponible Analyse des déformations dans un réseau géodésique d'auscultation d'ouvrage d'art / A. Belhadj in Bulletin des sciences géographiques, n° 28 (juin 2013)PermalinkAssessment of correct fixing rate for precise point positioning ambiguity resolution on a global scale / Xiaohong Zhang in Journal of geodesy, vol 87 n° 6 (June 2013)PermalinkRéflectométrie GNSS : modélisation des trajets des signaux réfléchis à la surface de la mer / Nicolas Roussel in XYZ, n° 135 (juin - août 2013)PermalinkInfluence of a dense, low-height shrub species on the accuracy of a lidar-derived DEM / Samuel B. Gould in Photogrammetric Engineering & Remote Sensing, PERS, vol 79 n° 5 (May 2013)PermalinkFast error analysis of continuous GNSS observations with missing data / M.S. Bos in Journal of geodesy, vol 87 n° 4 (April 2013)PermalinkSatellite altimetry calibration and deformation monitoring using GNSS / Pascal Willis in Advances in space research, vol 51 n° 8 (April 2013)PermalinkMéthodes de travail dans les réseaux GNSS, 3ème partie Méthodes du "statique multi-stations" / Romain Legros in XYZ, n° 134 (mars - mai 2013)PermalinkMitigating the impact of ionospheric cycle slips in GNSS observations / Simon Banville in Journal of geodesy, vol 87 n° 2 (February 2013)PermalinkApport du système de navigation GLONASS à la surveillance de l'ionosphère au dessus de l'Europe / Emilie Pelletier (2013)PermalinkE-GVAP, un proyecto europeo meteorológico con GNSS. Participación del IGN / Marcelino Valdés Pérez de Vargas in Topografia y cartografia, vol 28 n° 165 (2013)Permalink