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Vers la prise en compte de la dépendance spatio temporelle des séries de position GNSS dans leur analyse / Clément Benoist (2016)
Titre : Vers la prise en compte de la dépendance spatio temporelle des séries de position GNSS dans leur analyse Type de document : Article/Communication Auteurs : Clément Benoist , Auteur ; Paul Rebischung , Auteur ; Zuheir Altamimi , Auteur Editeur : Saint-Mandé : Institut national de l'information géographique et forestière - IGN (2012-) Année de publication : 2016 Conférence : Journées Recherche de l'IGN 2016, 25es Journées 24/03/2016 25/03/2016 Champs-sur-Marne France open access abstracts Importance : 1 p. Note générale : bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] bruit rose
[Termes IGN] densité spectrale de puissance
[Termes IGN] filtre de Kalman
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] méthode du maximum de vraisemblance (estimation)
[Termes IGN] modèle numérique
[Termes IGN] station GNSS
[Termes IGN] station permanenteRésumé : (auteur) Sur chaque composante du repère topocentrique (N; E; U), nous modélisons le mouvement des stations GNSS par une composante linéaire, une composante harmonique annuelle et semi-annuelle et un bruit, éventuellement plus raffiné qu’un simple bruit blanc homogène. Nous utilisons notamment le bruit de scintillation, bruit défini par sa densité spectrale de puissance proportionnelle à 1=f ; cela permet d’obtenir une incertitude plus réaliste sur les vitesses des stations. Le modèle tient compte des éventuelles discontinuités de position et de vitesse correspondant, par exemple, à des séismes et à des changements d’antenne. Les caractéristiques du bruit seront estimées, station par station, par maximum de vraisemblance. La suite de la thèse sera d’utiliser un filtre de Kalman tenant compte de la corrélation spatio-temporelle. Cette étude contribue à l’amélioration de l’ITRF, repère terrestre international de référence. Numéro de notice : C2016-013 Affiliation des auteurs : LASTIG LAREG (2012-mi2018) Thématique : POSITIONNEMENT Nature : Poster nature-HAL : Poster-sans-CL DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82949 Documents numériques
en open access
Vers la prise en compte de la dépendance spatio temporelleAdobe Acrobat PDF Wide-area ionospheric delay model for GNSS users in middle- and low-magnetic-latitude regions / An-Lin Tao in GPS solutions, vol 20 n° 1 (January 2016)
[article]
Titre : Wide-area ionospheric delay model for GNSS users in middle- and low-magnetic-latitude regions Type de document : Article/Communication Auteurs : An-Lin Tao, Auteur ; Shau-Shiun Jan, Auteur Année de publication : 2016 Article en page(s) : pp 9 - 21 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse comparative
[Termes IGN] Asie (géographie politique)
[Termes IGN] modèle ionosphérique
[Termes IGN] Quasi-Zenith Satellite System
[Termes IGN] retard ionosphèrique
[Termes IGN] station permanente
[Vedettes matières IGN] Traitement de données GNSSRésumé : (Auteur) A useful ionospheric delay model to compensate for the effect of ionospheric error on GNSS service over continent-wide areas or oceans is the Satellite-Based Augmentation System’s wide-area thin-shell planar fit ionospheric grid model. In order to implement a proper wide-area ionospheric delay model in the Asia-Pacific region to reflect the variation introduced by local ionospheric activity, the present study develops a proper ionospheric delay model to correct ionospheric error in middle- and low-magnetic-latitude regions. Specifically, the proposed ionospheric delay model uses several dual-frequency GNSS reference stations distributed in Taiwan, South Korea, Japan, and China as grid points in place of the conventional grid points generated by ionospheric pierce points. The ionospheric delays observed at the reference stations are processed and provided to the user, who can then construct the ionospheric delay model using weighted least squares with the distances between the user and the stations as weights. This proposed ionospheric delay model lowers the computation load by eliminating the conversion of delays at the ionospheric pierce points to those at the grid points and provides good descriptions of dynamic variations due to the ionospheric activities. Also, a simplified model is developed to further reduce its computation load while providing almost the same service as that of the original proposed model. A selection mechanism between the original proposed model and its simplified version is developed as well. The details of the proposed ionospheric delay model are explained, and experiments conducted using data collected from the reference stations in the Asia-Pacific region are presented. The effectiveness of the proposed model is validated by comparison with the conventional wide-area thin-shell planar fit ionospheric grid model provided by the Japanese Multi-functional Satellite Augmentation System under both nominal and disturbed ionospheric conditions. Numéro de notice : A2016-601 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-014-0435-z En ligne : http://dx.doi.org/10.1007/s10291-014-0435-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81787
in GPS solutions > vol 20 n° 1 (January 2016) . - pp 9 - 21[article]Single-frequency precise point positioning: an analytical approach / Oskar Sterle in Journal of geodesy, vol 89 n° 8 (August 2015)
[article]
Titre : Single-frequency precise point positioning: an analytical approach Type de document : Article/Communication Auteurs : Oskar Sterle, Auteur ; Bojan Stopar, Auteur ; Polona Pavlovčič Prešeren, Auteur Année de publication : 2015 Article en page(s) : pp 793-810 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse comparative
[Termes IGN] analyse de données
[Termes IGN] coordonnées géographiques
[Termes IGN] horloge
[Termes IGN] positionnement ponctuel précis
[Termes IGN] propagation troposphérique
[Termes IGN] récepteur monofréquence
[Termes IGN] station permanente
[Termes IGN] transformation de Helmert
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) An analytical approach to single-frequency precise point positioning (PPP) is discussed in this paper. To obtain highest precision results, all biases must be eliminated or modelled to centimetre level. The use of the GRAPHIC ionosphere-free linear combination that is based on single-frequency phase and code observations eliminates the ionosphere bias; however, the rank deficient Gauss–Markov model is obtained. We explicitly determine rank deficiency of a Gauss–Markov model as a number of all ambiguity clusters, each of them defined as a set of all ambiguities overlapping in time. On the basis of S-transformation we prove that the single-frequency PPP represents an unbiased estimator for station coordinates and troposphere parameters, while it presents a biased estimator for ambiguities and receiver-clock error parameters. Additionally we describe the estimable parameters in each ambiguity cluster as the differences between ambiguity parameters and the sum of receiver-clock parameters with one of the ambiguities. We also show that any other particular solution on the basis of S-transformation is obtained only when the common least-squares estimation in single step is applied. The recursive least-squares estimation with parameter pre-elimination only determines the vector of unknowns as possible to transform through S-transformation, whereas the same does not hold for the cofactor matrix of unknowns. For a case study, we present our method on GPS data from 19 permanent stations (14 IGS and 5 EPN) in Europe, for 89 consecutive days in the beginning of 2013. The static case study revealed the precision of daily coordinates as 7.6, 11.7 and 19.6 mm for N, E and U, respectively. The accuracies of the N, E and U components were determined as 6.9, 13.5 and 31.4 mm, respectively, and were calculated using the Helmert transformation of weighted-mean daily single-frequency PPP and IGb08 coordinates. The estimated convergence times were relatively diverse, expanding from 1.75 h (CAGL) to 5.25 h (GRAZ) for the horizontal position with the 10-cm precision threshold, and from 1.00 h (GRAS) to 3.25 h (BZRG) for the height component with a 20-cm precision threshold. The convergence times were shown to be strongly correlated to the remaining unmodelled biases in the GRAPHIC linear combination, primarily with multipath, where the correlation coefficient for the horizontal position was determined as ρP = 0.68 and for height as ρU = 0.85. The comparison to the model where raw observations are used (C, L) and where the ionosphere bias is mitigated with global ionosphere models (GIM) revealed the supremacy of the proposed single-frequency PPP method based on the GRAPHIC linear combination in both the static and the semi-kinematic case study. In the static case study, the proposed single-frequency PPP model was superior both in terms of precision and accuracy. In the semi-kinematic case study, the usage of raw observations with GIM would improve results only when multipath and noise of code observations would prevail over the remaining ionosphere bias, i.e. after applying GIM. Numéro de notice : A2015-377 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0816-2 Date de publication en ligne : 29/04/2015 En ligne : https://doi.org/10.1007/s00190-015-0816-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76855
in Journal of geodesy > vol 89 n° 8 (August 2015) . - pp 793-810[article]Development of an improved empirical model for slant delays in the troposphere (GPT2w) / Johannes Böhm in GPS solutions, vol 19 n° 3 (July 2015)
[article]
Titre : Development of an improved empirical model for slant delays in the troposphere (GPT2w) Type de document : Article/Communication Auteurs : Johannes Böhm , Auteur ; Gregor Möller, Auteur ; Michael Schindelegger, Auteur ; Grégory Pain, Auteur ; Robert Weber, Auteur Année de publication : 2015 Article en page(s) : pp 433 - 441 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] coordonnées GNSS
[Termes IGN] erreur systématique
[Termes IGN] modèle empirique
[Termes IGN] retard troposphérique
[Termes IGN] station permanente
[Termes IGN] teneur en vapeur d'eauRésumé : (Auteur) Global pressure and temperature 2 wet (GPT2w) is an empirical troposphere delay model providing the mean values plus annual and semiannual amplitudes of pressure, temperature and its lapse rate, water vapor pressure and its decrease factor, weighted mean temperature, as well as hydrostatic and wet mapping function coefficients of the Vienna mapping function 1. All climatological parameters have been derived consistently from monthly mean pressure level data of ERA-Interim fields (European Centre for Medium-Range Weather Forecasts Re-Analysis) with a horizontal resolution of 1°, and the model is suitable to calculate slant hydrostatic and wet delays down to 3° elevation at sites in the vicinity of the earth surface using the date and approximate station coordinates as input. The wet delay estimation builds upon gridded values of the water vapor pressure, the weighted mean temperature, and the water vapor decrease factor, with the latter being tuned to ray-traced zenith wet delays. Comparisons with zenith delays at 341 globally distributed global navigation satellite systems stations show that the mean bias over all stations is below 1 mm and the mean standard deviation is about 3.6 cm. The GPT2w model with the gridded input file is provided at. Numéro de notice : A2015--112 Affiliation des auteurs : ENSG+Ext (2012-2019) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-014-0403-7 Date de publication en ligne : 26/08/2014 En ligne : https://doi.org/10.1007/s10291-014-0403-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90646
in GPS solutions > vol 19 n° 3 (July 2015) . - pp 433 - 441[article]Documents numériques
en open access
Development of an improved ... - pdf éditeurAdobe Acrobat PDF Divisional ambiguity resolution for long range reference stations in network RTK / J. Deng in Survey review, vol 47 n° 343 (July 2015)
[article]
Titre : Divisional ambiguity resolution for long range reference stations in network RTK Type de document : Article/Communication Auteurs : J. Deng, Auteur ; S.L. Wang, Auteur Année de publication : 2015 Article en page(s) : pp 272 - 278 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] analyse comparative
[Termes IGN] fractionnement
[Termes IGN] ligne de base
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] résolution d'ambiguïté
[Termes IGN] station permanenteRésumé : (auteur) Increasing the distance between reference stations of network RTK can improve the flexibility of the reference stations sitting, reduce the number of reference stations and cut down construction and maintenance costs. However, it also decreases the correlation of spatial error and affects the real time performance and effectiveness of the network RTK positioning. Thus, the key techniques of long range network RTK need to be further optimised. Ambiguity resolution between reference stations is one of the most critical techniques. In this paper a divisional ambiguity resolution for long range reference stations of network RTK is proposed, so as to deal with the long fixed time and low success rate, especially for low elevation satellites. Based on conventional two-step ambiguity resolution, firstly, this new method calculates the wide-lane ambiguity by building M-W combination of pseudo-range and carrier observations. Second, the conventional ambiguity resolution as a whole is changed and satellites are divided into high elevation ones and low elevation ones, then the integer ambiguity of high elevation satellites is resolved by means of ionosphere-free combination with the relative zenith wet delay as a parameter. Finally, the Kalman filter model is established by the observation equation of high elevation satellites with calculated ambiguity and low elevation satellites, assisting to obtain the ambiguity of low elevation satellites quickly. The example selects a 196 km long baseline for comparative analysis. Result shows that it takes 733 s to resolve the ambiguity of all satellites by conventional ambiguity resolution in whole, and 252 s by divisional ambiguity resolution proposed in this paper. The new method saves about two thirds of resolution time, and also greatly improves the efficiency of ambiguity resolution of low elevation satellites for long baseline. Numéro de notice : A2015-921 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270614Y.0000000123 En ligne : https://doi.org/10.1179/1752270614Y.0000000123 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79732
in Survey review > vol 47 n° 343 (July 2015) . - pp 272 - 278[article]L'ITRF fête ses trente ans / Anonyme in Géomatique expert, n° 105 (juillet - août 2015)PermalinkContribution de l'Institut National de l'Information Géographique et Forestière à la réalisation du repère de référence terrestre de GALILEO / Jonathan Chenal in XYZ, n° 143 (juin - août 2015)PermalinkGalileo E1 and E5a Performance for multi-frequency, multi-constellation GBAS / Mihaela-Simona Circiu in GPS world, vol 26 n° 4 (April 2015)PermalinkChamp de vitesse GPS du Nord-Est de la France : apport des stations permanentes pour une précision submillimétrique / Eric Henrion in XYZ, n° 142 (mars - mai 2015)PermalinkPermalinkPermalinkGéodésie multi-technique pour la surveillance haute fréquence de glissements de terrains / Pierre Boetzle (2015)PermalinkPermalinkPermalinkSurcharges océaniques dans les signaux GPS : la quète de l'extrêmement petit / Christine Heimlich in XYZ, n° 139 (juin - août 2014)Permalink