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Optimizing a network-based RTK method for OTF [on-the-fly] positioning / L.P. Fortes in GPS solutions, vol 7 n° 2 (August 2003)
[article]
Titre : Optimizing a network-based RTK method for OTF [on-the-fly] positioning Type de document : Article/Communication Auteurs : L.P. Fortes, Auteur ; M.E. Cannon, Auteur ; et al., Auteur Année de publication : 2003 Article en page(s) : pp 61 - 73 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] covariance
[Termes IGN] erreur
[Termes IGN] filtre de Kalman
[Termes IGN] ionosphère
[Termes IGN] méthode des moindres carrés
[Termes IGN] optimisation (mathématiques)
[Termes IGN] orbite
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] précision centimétrique
[Termes IGN] résolution d'ambiguïté
[Termes IGN] station de référence
[Termes IGN] valeur efficaceRésumé : (Auteur) Differential GPS is able to provide cm-level positoning accuracies, as long as the carrier phase ambiguities are resolved to integer values. Classical methods are based on the use of a single reference station located in the vicinity of the rover. Due to the spatial decorrelation of the errors, the distance between the reference station and the user is generally limited to within 20-30 km or even less, mainly due to the ionosphere. The MultiRef method, developed at the University of Calgary, uses a network of reference stations to generate regional code and carrier phase corrections, which can be transmitted to users in order to increase the distance over which integer ambiguity resolution is possible. In the original method, the correlated errors, due to the satellite orbits, troposphere, and ionosphere are modeled together using the L1 and wide-lane observables. In this paper extensive efforts were carried out towards as optimizing the MultiRef method with the objective of maximizing its performance. Data collected in southeastern Brazil was used in this research. At first, the impact of using covariance function calculated with different data sets was assessed, showing improvement variations of up to 14% in the observation domain compared to using no network corrections, with the exact improvement depending on the data set used in the computation. A new approach, also using least-squares prediction (collation), was proposed to separately model the correlated errors. An additional effort was carried out in the terms of modeling the ionosphere into directional components. Results of the enhanced method showed the same level of improvement as those obtained using the original covariance functions. However, this new approach has advantages with respect to the transmission of the corrections. Finally, an additional step was taken in terms of applying a Kalman filter to the corrections in order to improve their quality. For cases when the corresponding satellite was setting at low elevations, the filter approach improved results up to 44%. A study on the impact of the various covariance functions on the estimated accuracy of the corrections is also included. Numéro de notice : A2003-370 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-003-0054-6 En ligne : https://doi.org/10.1007/s10291-003-0054-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26450
in GPS solutions > vol 7 n° 2 (August 2003) . - pp 61 - 73[article]An overview of multi-reference station methods for cm-level positioning / Georgia Fotopoulos in GPS solutions, vol 4 n° 3 (January 2001)
[article]
Titre : An overview of multi-reference station methods for cm-level positioning Type de document : Article/Communication Auteurs : Georgia Fotopoulos, Auteur ; M.E. Cannon, Auteur Année de publication : 2001 Article en page(s) : pp 1 - 10 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] GPS en mode différentiel
[Termes IGN] interpolation linéaire
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] positionnement différentiel
[Termes IGN] positionnement par GPS
[Termes IGN] résolution d'ambiguïté
[Termes IGN] station de référence
[Termes IGN] station virtuelleRésumé : (Auteur) Over the past few years, a significant amount of research has been conducted on the information of carrier phase correction in order to enhance ambiguity resolution and to increase the distances over wich precise positioning can be achieved. Recently the use of a network of multiple GPS reference stations for generating carrier phase-based corrections has emerged with great promise for use in real-time environments. However, little research has been conducted on the distribution of these correction to potential GPS users located within, and surrounding, the network coverage area. This is an integrated part of real-time kinematic DGPS, and it must be adequately adressed before a pratical realization of the multi-reference station concept is implemented. The focus of this paper is to present a comprehensive summary of some of the multiple reference station methods, with specific attention directed toward the correction generation and dissemination processes. More specifically, the various multi-reference station methodologies have been categorized according to their underlying correction generation framework, but will be discusse in terms of the correction dissemination options presented by various authors. The four main categories of methods investigated in this paper are : (a) partial derivative algorithms, (b) linear interpolation algorithms, (c) condition adjustement algorithms and (d) virtual reference station methodologies. Numéro de notice : A2001-060 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/PL00012849 En ligne : https://doi.org/10.1007/PL00012849 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26399
in GPS solutions > vol 4 n° 3 (January 2001) . - pp 1 - 10[article]ITRF97 and quality analysis of IGS reference stations / Zuheir Altamimi (2001)
Titre : ITRF97 and quality analysis of IGS reference stations Type de document : Article/Communication Auteurs : Zuheir Altamimi , Auteur ; Claude Boucher , Auteur ; Patrick Sillard , Auteur Editeur : Paris : Institut Géographique National - IGN (1940-2007) Année de publication : 2001 Collection : Publications du LAREG Sous-collection : Communications Conférence : IGS 1999, Workshop 05/06/1999 11/06/1999 La Jolla Californie - Etats-Unis Importance : 8 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] qualité des données
[Termes IGN] station de référenceIndex. décimale : 30.10 Systèmes de référence et réseaux géodésiques Résumé : (auteur) A brief description of the 1997 International Terrestrial Reference Frame (ITRF97) is presented, underlying the most important results in terms of quality assessment. The qua-lity of the 52 IGS Reference Stations is reviewed, based on the ITRF97 post fit position and velocity residuals. The noticeable improvement of ITRF97 with respect to ITRF96 leads to the recommendation of the use of ITRF97 instead of ITRF96. Moreover, the quality of the 5 ITRF96 rejected stations is significantly improved with ITRF97, and so all the 52 stations could be used by IGS as Reference Stations. Although ITRF94, ITRF96 and ITRF97 are globally aligned in terms of datum definition, transformation parameters were estimated and commented, between the 3 IGS reference station sets (the 13 ITRF94, 47 ITRF96 and the 52 ITRF97). Numéro de notice : 25191 Affiliation des auteurs : LAREG (1991-2011) Thématique : POSITIONNEMENT Nature : Communication DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93252 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 25191-01 30.10 Livre Centre de documentation Géodésie Disponible Präzise Positionierung in regionalen GPS-Referenzstationsnetzen / Lambert Wanninger (2000)
Titre : Präzise Positionierung in regionalen GPS-Referenzstationsnetzen Titre original : [Positionnement de précision dans les réseaux régionaux de stations GPS] Type de document : Thèse/HDR Auteurs : Lambert Wanninger, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 2000 Collection : DGK - C Sous-collection : Dissertationen num. 508 Importance : 68 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-9556-4 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] ambiguïté entière
[Termes IGN] correction atmosphérique
[Termes IGN] Europe centrale
[Termes IGN] phase GPS
[Termes IGN] positionnement par GPS
[Termes IGN] précision centimétrique
[Termes IGN] réseau géodésique permanent
[Termes IGN] station de référence
[Termes IGN] station GPS
[Termes IGN] station virtuelle
[Termes IGN] traitement de données GNSSIndex. décimale : 30.61 Systèmes de Positionnement par Satellites du GNSS Résumé : (Auteur) Permanent GPS reference stations produce observation corrections to be used for cm-accurate relative positioning and they establish the connection to a geodetic reference frame. In order to supply observation corrections for larger areas at minimum costs, the number of reference stations should be as small as possible, but large enough to guarantee cm-accuracy. The solution lies in the precise modeling of the distance and direction dependent errors.
Error modeling based on GPS phase data requires fixing of the carrier phase ambiguities in the network of reference stations. It could be shown, both theoretically and with real observation data, that a two-dimensional linear interpolation algorithm yields mm-accurate corrections if the reference station distances do not exceed 100 km.
However, if regional scale disturbances exist in the ionosphere or in the troposphere, larger errors can be encountered. For the application in Central Europe, it is therefore recommended to limit the reference station distances to some 50 km.
The realization of this positioning concept is performed in two steps. In the first one, the observations of the reference stations are preprocessed and separated into observation correction of one base station and correction models for the distance and direction dependent errors. In the second step, virtual observations of a reference station at a selected position are calculated. They can then be used for the positioning of a rover receiver in baseline mode using existing software.
The processing of various test data sets showed that in Central Europe and with reference station distances of some 50 km, 1cm accurate horizontal coordinates could be obtained within a few minutes. Since the distance and direction dependent errors can almost completely be corrected, the necessary observation time at a rover site is mainly a function of the rover receiver's data quality.Numéro de notice : 46139 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=58472 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 46139-02 30.61 Livre Centre de documentation Géodésie Disponible 46139-01 30.61 Livre Centre de documentation Géodésie Disponible Les positions des stations du réseau GPS permanent / M. Suing (1999)
Titre : Les positions des stations du réseau GPS permanent Type de document : Mémoire Auteurs : M. Suing, Auteur Editeur : Paris : Institut Géographique National - IGN (1940-2007) Année de publication : 1999 Collection : Publications du LAREG Sous-collection : Mémoire de stage Importance : 59 p. Format : 21 x 30 Note générale : Mémoire de stage de fin d'études ESGT Langues : Français (fre) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] éphémérides de satellite
[Termes IGN] European Terrestrial Reference Frame
[Termes IGN] international GPS service for geodynamics
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] positionnement par GPS
[Termes IGN] réseau géodésique permanent de l'IGN
[Termes IGN] série temporelle
[Termes IGN] station de référence
[Termes IGN] station GPSIndex. décimale : ESGT Mémoires d'ingénieurs de l'ESGT Résumé : (Auteur) En cette période charnière de l'installation du réseau GPS permanent, il peut paraître opportun d'effectuer une première analyse des variations de positions de ces stations au cours du temps et en fonction du mode de calcul. Numéro de notice : 11075 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Mémoire ingénieur ESGT Organisme de stage : LAREG (IGN) Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=49502 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 11075-01 ESGT Livre Centre de documentation En réserve Mezzanine Disponible 11075-02 ESGT Livre Centre de documentation En réserve Mezzanine Disponible The IERS network and the concept of the fundamental geodynamic reference stations / Claude Boucher (1995)PermalinkResults and analysis of the ITRF93 / Zuheir Altamimi (1994)PermalinkThe IFE absolute gravity program "South America" 1988 - 1991 / Wolfgang Torge (1994)PermalinkInternational absolute gravity basestation network / G. Boedecker (1986)PermalinkBestimmung astronomischer Längendifferenzen für das Europäische Längennetz in den Jahren 1977 bis 1979 / K. Kaniuth (1980)Permalink