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Fast precise GPS positioning in the presence of ionospheric delays / Dennis Odijk (2002)
Titre : Fast precise GPS positioning in the presence of ionospheric delays Type de document : Monographie Auteurs : Dennis Odijk, Auteur Editeur : Delft : Netherlands Geodetic Commission NGC Année de publication : 2002 Collection : Netherlands Geodetic Commission Publications on Geodesy, ISSN 0165-1706 num. 52 Importance : 242 p. Format : 16 x 24 cm ISBN/ISSN/EAN : 978-90-6132-278-8 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] ambiguïté entière
[Termes IGN] correction ionosphérique
[Termes IGN] correction troposphérique
[Termes IGN] données GPS
[Termes IGN] interpolation
[Termes IGN] krigeage
[Termes IGN] mesurage de phase
[Termes IGN] méthode des moindres carrés
[Termes IGN] modèle de Gauss-Markov
[Termes IGN] modèle ionosphérique
[Termes IGN] modèle stochastique
[Termes IGN] propagation ionosphérique
[Termes IGN] propagation troposphérique
[Termes IGN] réfraction atmosphérique
[Termes IGN] résolution d'ambiguïté
[Termes IGN] signal GPS
[Termes IGN] station virtuelle
[Termes IGN] traitement de données GNSS
[Termes IGN] traitement du signalIndex. décimale : 30.61 Systèmes de Positionnement par Satellites du GNSS Résumé : (Auteur) This thesis deals about geodetic applications of the Global Positioning System (GPS), in which the position of the GPS receiver must be determined with cm precision. This requires a relative measurement setup, together with an advanced processing strategy based on observations of the carrierphase of the signal. To keep it economically interesting, this CPS technique should be based on relatively short time spans in which the satellite observations are collected. The key to precise positioning using short time spans is to take advantage of the integer property of the ambiguities of the phase observations in the processing.
The above procedure has been applied in a successful way for the last decade to applications in which the distance between the receivers is restricted to about 10 km (the socalled rapidstatic and realtime kinematic GPS techniques over short distances). Above this distance, it is known that certain errors in the GPS observations start to significantly bias the computed receiver position when they are not taken care of. The aim of this research therefore is to develop a processing procedure, taking into account the errors in GPS observations due to propagation of the signals through the ionosphere, the atmospheric layer above about 80 kill. Although other errors (due to troposphere and satellite orbit) are of relevance as well, the research is restricted to an improved modelling of the ionospheric error. since it is by far the largest error. For the other errors standard modelling techniques are applied in this research. Using the procedure, it should be possible to determine the desired receiver positions with cmprecision using a short tinle span. The research is restricted to GPS receivers with a mutual distance of a few hundred km (mediumdistance baselines), located in midlatitude regions.
To facilitate a modelling of the ionospheric error, using the theor ' y of atmospheric refraction it is possible to decompose this error into a firstorder effect, which contains the gross of the error, plus some higherorder effects and a term due to bending of the signal path. Under worstcase conditions. the firstorder term may range up to about 80 m (on the GPS L2 frequency), whereas the accumulated effect of higherorder and bending terms can be tip to 4 cm (for L2). For the future L5 frequency (from 2008) these effects are even larger. Fortunately, because of the relative setup and the assumed medium distances, it is proved for this research it is allowed to neglect the higherorder and bending errors.
In the procedure a stochastic modelling of the firstorder ionospheric errors (referred to as ionospheric delays) is chosen. This means that the ionospheric delays are not modelled as completely unknown parameters, but that stochastic prior information is incorporated by means of ionospheric pseudoobservations. This model is referred to as the ionosphereweighted model: The weight of the ionospheric information can be tuned by the a priori standard deviation of the pseudoobservations. When this standard deviation is chosen zero, the ionosphereweighted model reduces to the ionospherefixed model, which is the usual processing model for shortdistance baselines (for which the ionospheric delays may be neglected). On the other hand, with an infinitely large ionospheric standard deviation, the model will be equivalent to the ionospherefloat model, in which the ionospheric delays are assumed as completely unknown parameters. This latter model is closely related to the ionospherefree combination, for which it is known that it cannot be used to achieve fast positioning results. It is shown that the ionosphereweighted model is only suitable for fast ambiguity resolution (and consequently positioning), when the ionospheric standard deviation is small. This requires very precise a priori ionospheric information.
The developed procedure consists of three steps. It is required that a user collects CPS observations in the vicinity of a network of permanent GPS stations. In the first step, the observations at the network stations are processed simultaneously using the ionosphereweighted model. Since in this research the goal is precise positioning within the shortest time span possible, i.e. instantaneous or singleepoch positioning, it is required that the network data is also processed instantaneously. To make instantaneous resolution of the network ambiguities possible, the sample values of the ionospheric pseudoobservations are temporal predictions based on estimates of previous epochs. Test computations using a network with a station spacing of more than 100 km demonstrated that in this way high network ambiguity success rates (close to 100%) can be obtained. In the second step, precise ambiguityfixed network ionospheric delays are spatially interpolated at the approximate location of the user's receiver. In the procedure for this purpose the concept of virtual reference station (VRS) observations is used. In this concept the network estimates (ionospheric delays and other parameters) are transformed to VRS observations. which should correspond to the data a real receiver would have collected at the user's location. The processing of the user's observations relative to this VRS is the third step of the procedure. Because of the presence of possible residual ionospheric delays also in this step the ionosphereweighted model is applied. The difference with the application in the network processing is that the sample values of the pseudoobservations are now taken zero. and the ionospheric standard deviation is computed as a function of the distance to the closest real network station. Using this, test computations demonstrated that instantaneous ambiguity success rates of 90% are feasible. When the ionospherefixed model would be applied, the success rates would not be higher than about 60%.Numéro de notice : 13101 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=54884 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 13101-01 30.61 Livre Centre de documentation Géodésie Disponible Bestimmung des Gesamtelektroneninhalts der Ionosphäre aus PRARE-Entfernungs- und Dopplerbeobachtungen / Frank Flechtner (2000)
Titre : Bestimmung des Gesamtelektroneninhalts der Ionosphäre aus PRARE-Entfernungs- und Dopplerbeobachtungen Titre original : [Détermination du contenu total en électrons de l'ionosphère à partir des observations de télémétrie doppler de PRARE] Type de document : Monographie Auteurs : Frank Flechtner, Auteur Editeur : Postdam : GeoForschungsZentrum Postdam Année de publication : 2000 Collection : Scientific technical reports num. 00/02 Importance : 135 p. Format : 21 x 30 cm Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] données PRARE
[Termes IGN] ionosphère
[Termes IGN] positionnement par PRARE
[Termes IGN] teneur totale en électronsIndex. décimale : 30.84 Applications de géodésie spatiale à l'atmosphère Résumé : (Auteur) Since many years, geodetic and geophysical quantities such as satellite orbits, ground station coordinates, Earth rotation parameters or Earth gravity field models are determined using radio or optical signals transmitted between ground stations and satellites. Beside many other disruptive factors, microwave observations are influenced to a great extent by the spatial and temporal highly variable behaviour of the Ionosphere. This leads usually to a change in signal travel time, but may also cause the complete loss of the signal. The fundamental parameter which describes the condition of the ionosphere is the total electron content (TEC). Because the ionosphere is a dispersive medium, TEC can be determined by measuring the travel time difference between two simultaneously transmitted signals of different frequency. Therefore, the German satellite tracking system PRARE (Precise Range And Range Rate Equipment) on ESA's remote sensing satellite ERS2 is also operated on two coherent frequencies. Unique with PRARE is the fact that the ionospheric parameters can alternatively be calculated from quasisimultaneous independent range and doppler measurements of the PRARE space segment. This method is called Differenced Range Versus Integrated Doppler (DRVID) and makes use of the different refraction index of code and phase measurements in refractive media such as the ionosphere. After a short introduction to the subject of this thesis the main characteristics of the PRARE system are presented, followed by the description of the properties of the Earth's atmospheric layers under special consideration of the refractivity and the spatial and temporal variations of the ionosphere. This more general part is completed by a survey of the presently used methods and models for the derivation of TEC. The data preprocessing of PRARE range and doppler measurements is the basis to derive the PRARE typical DRVID method. It is shown that this procedure is suitable to precisely derive the TEC and to detect multipath on PRARE range observations caused by the solar array of ERS-2. Different ideas for the necessary relative and absolute calibration of PRARE TEC values are discussed and carried out using two global ionospheric models, IRI95 and CODEGIM. The following comparison of simultaneous PRARE DRVID data with each other and with independent twofrequency TOPEX/POSEIDON altimeter observations shows their high reliability and quality. It is shown that especially under increasing solar activity and by further extension of the PRARE ground tracking network over the oceans the singlefrequency ERS-2 altimeter observations can be improved by means of PRARE TEC measurements. Finally, as an additional result of the experience gained during this work, some concrete suggestions for improvement of the PRARE system in case of operation on future satellite missions are presented. Numéro de notice : 15049 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=55053 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 15049-01 30.84 Livre Centre de documentation Géodésie Disponible Mapping and predicting the Earth's ionosphere using the Global Positioning System / Stefan Schaer (1999)
Titre : Mapping and predicting the Earth's ionosphere using the Global Positioning System Type de document : Monographie Auteurs : Stefan Schaer, Auteur Editeur : Zurich : Schweizerischen Geodatischen Kommission / Commission Géodésique Suisse Année de publication : 1999 Collection : Geodätisch-Geophysikalische Arbeiten in der Schweiz, ISSN 0257-1722 num. 59 Importance : 205 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-908440-01-7 Note générale : Bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] carte thématique
[Termes IGN] harmonique sphérique
[Termes IGN] ionosphère
[Termes IGN] modèle atmosphérique
[Termes IGN] propagation ionosphérique
[Termes IGN] série temporelle
[Termes IGN] signal GPS
[Termes IGN] teneur totale en électronsIndex. décimale : 30.84 Applications de géodésie spatiale à l'atmosphère Numéro de notice : 67957 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie En ligne : https://www.sgc.ethz.ch/sgc-volumes/sgk-59.pdf Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=61833 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 67957-01 30.84 Livre Centre de documentation Géodésie Disponible Spécial recherche 1999 / Université Paris-Sud (1999)
Titre : Spécial recherche 1999 : la Terre dans tous ses états Type de document : Monographie Auteurs : Université Paris-Sud, Auteur Editeur : Paris-Orsay : Université de Paris 11 Paris-Sud Centre d'Orsay Année de publication : 1999 Importance : 23 p. Format : 21 x 30 cm Langues : Français (fre) Descripteur : [Vedettes matières IGN] Environnement
[Termes IGN] ionosphère
[Termes IGN] observation de la Terre
[Termes IGN] pollution
[Termes IGN] télédétectionNuméro de notice : 11017 Affiliation des auteurs : non IGN Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=54341 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 11017-01 50.00 Livre Centre de documentation Environnement Disponible IGS network - systems worshop / Carey E. Noll (1998)
Titre : IGS network - systems worshop Type de document : Actes de congrès Auteurs : Carey E. Noll, Éditeur scientifique ; Ken Gowey, Auteur ; Ruth E. Neilan, Auteur Editeur : Pasadena : Jet Propulsion Laboratory JPL Année de publication : 1998 Conférence : JPL 1998, IGS network - systems worshop 02/11/1998 05/11/1998 Annapolis Maryland - Etats-Unis Importance : 362 p. Format : 21 x 30 cm Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Global Orbitography Navigation Satellite System
[Termes IGN] Global Positioning System
[Termes IGN] international GPS service for geodynamics
[Termes IGN] ionosphère
[Termes IGN] positionnement par GPS
[Termes IGN] tectoniqueNuméro de notice : 67428 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Actes Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=37062 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 67428-01 CG.98 Livre Centre de documentation Congrès Disponible Real-time estimation of ionospheric delay using GPS measurements / L.S. Lin (1998)PermalinkLes applications scientifiques du système Doris / Pascal Willis (25/11/1997)PermalinkEvaluation du nouveau modèle du Bernese software / Serge Botton in Bulletin d'information de l'Institut géographique national, n° 68 (octobre 1997)PermalinkSystème DORIS : applications scientifiques / Pascal Willis in XYZ, n° 73 (septembre - novembre 1997)PermalinkProceedings of the national technical meeting Navigation and positioning in the information age, January 14-16, 1997, Santa Monica, California / Institute of navigation (1997)PermalinkEtude du comportement du contenu électronique total et de ses irrégularités dans une région de latitude moyenne / René Warnant (1996)PermalinkAnalysis of GPS data processing techniques / Dorota A. Grejner-Brzezinska (1995)PermalinkA recursive procedure for computation and quality control of GPS differential corrections / X. Jin (1995)PermalinkLes effets de l'atmosphère sur les liaisons radioélectriques / P. Bauer (1994)PermalinkPermalink