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A recursive procedure for computation and quality control of GPS differential corrections / X. Jin (1995)
Titre : A recursive procedure for computation and quality control of GPS differential corrections Type de document : Monographie Auteurs : X. Jin, Auteur Editeur : Delft [Pays-Bas] : Delft University of Technology Année de publication : 1995 Collection : LGR-SERIES num. 8 Importance : 83 p. Format : 21 x 30 cm Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] contrôle qualité
[Termes IGN] correction du signal
[Termes IGN] correction ionosphérique
[Termes IGN] erreur moyenne quadratique
[Termes IGN] erreur systématique
[Termes IGN] filtre de Kalman
[Termes IGN] GPS en mode différentiel
[Termes IGN] modèle ionosphérique
[Termes IGN] précision du positionnement
[Termes IGN] propagation ionosphérique
[Termes IGN] traitement de données GNSSIndex. décimale : 30.61 Systèmes de Positionnement par Satellites du GNSS Résumé : (Auteur) The DGPS technique can considerably improve the accuracy of stand-alone GPS positioning, since biases inherent in the latter technique are greatly reduced or even eliminated. But the improvement depends on the distance between the user and the reference station (spatial correlation), the latency of differential corrections (temporal correlation), and the quality of differential corrections. Therefore, how to correctly generate differential corrections is one of the keys to the DGPS positioning technique. Currently, there already exist several algorithms for the generation of differential corrections, for instance, the algorithm based on carrier filtered code observations and the algorithm based on code observations and sequential differences of carrier observations.
This research derives a new algorithm for generating differential corrections along with a recursive quality control procedure, which has some distinct features. First, it directly uses code and carrier observations in the measurement model of a Kalman filter, so that the measurements are not correlated in time if code and carrier observations can be assumed to have no time correlation. This makes it possible to use a simple stochastic observation model and to use the standard algorithm of the Kalman filter. Second, the algorithm accounts for biases like multipath errors and instrumental delays in code observations. It explicitly shows how code biases affect differential corrections when dual or single frequency data are used. Third, the algorithm can be easily integrated with a recursive quality control procedure, so that the quality of the estimated states can be guaranteed with certain probability. Fourth, in addition to the generation of differential corrections, it also produces the change of ionospheric delays and that of code biases with time. It can, therefore, be used to investigate properties of ionospheric delays and code biases. Finally, all state estimates including differential correction are not affected by the opposite influence of ionospheric delay on code and carrier observations.
On the basis of data collected by TurboRogue SNR-8000, Trimble 4000 SSE and Trirable 4000 SST receivers, this research also investigates the relationship between satellite elevation and the accuracy of code observations. Since this investigation uses code predicted residuals, which are dominated by code observation noises, the estimation of code observation accuracy is not affected by systematic errors caused by, for example, multipath and instrumental delays in code observations. It turns out that the deterioration of GPS code accuracy with decreasing elevation is very obvious at low elevation. When satellite elevation increases, the accuracy becomes more and more stable. The change of the code accuracy with satellite elevation can quite well be modelled by an exponential function of the form y=ao+a1.exp{-x/xo}, where y (the RMS error), ao and a1 have units of metres, and x (elevation) and xo are in degrees. For different types of receivers and different types of code observables, the parameters ao, a1 and xo may be different.
It is shown that by using code and carrier data with a sampling interval of one second, the dynamic behaviour of SA clock errors and that of ionospheric delays can well be modelled by quadratic and linear functions, respectively. The modelling accuracy is at least within a few millimetres.
Biases in code measurements are found and they may behave linearly and periodically with time. By using the same receiver, code biases related to different observation conditions have different behaviours and those related to the same satellite but observed in different frequencies (i.e. L1 and L2) may also not be the same.
Model testing experiments with simulated errors show that cycle slips as small as one cycle can be indeed successfully detected and identified in real time. The recursive quality control procedure allows for detection and identification of single as well as multiple model errors. But there exists a problem that the mean of the test statistic is always smaller than its expectation. It has been shown that this problem still remains after the relationship between satellite elevation and the accuracy of code observations is taken into account.
Based on the differential corrections generated by the new algorithm, it is shown that with increasing differential-correction latencies, the accuracy of differential-correction prediction decreases quadratically when SA clock errors are present and linearly when SA clock errors are absent. For latencies up to 5, 10 and 15 seconds, the accuracies are usually within 0.05, 0.2 and 0.5 in, respectively. Using differential-correction acceleration in differential-correction prediction can improve or worsen the accuracy when SA clock errors are present or absent, respectively. But the deteriorated accuracies related to satellites without SA clock errors are still better than the improved ones related to satellites with SA clock errors. For latencies within 15 seconds, the accuracy of differential-correction prediction can usually be reduced to below 0.2 metres if differential-correction accelerations are used.Numéro de notice : 18210 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=55351 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 18210-01 30.61 Livre Centre de documentation Géodésie Disponible Introduction à la géodésie spatiale, 1. 1ère partie Méthodes modernes en positionnement géodésique / Pascal Willis (1994)
Titre de série : Introduction à la géodésie spatiale, 1 Titre : 1ère partie Méthodes modernes en positionnement géodésique Type de document : Guide/Manuel Auteurs : Pascal Willis , Auteur Editeur : Paris : Institut Géographique National - IGN (1940-2007) Année de publication : 1994 Collection : Publications techniques en géodésie Sous-collection : Cours et conférences num. 27756 Importance : 24 p. Format : 21 x 30 cm Langues : Français (fre) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] correction ionosphérique
[Termes IGN] correction troposphérique
[Termes IGN] positionnement par géodésie spatiale
[Termes IGN] propagation ionosphérique
[Termes IGN] propagation troposphériqueIndex. décimale : 30.60 Géodésie spatiale Numéro de notice : 60611A Affiliation des auteurs : IGN (1940-2011) Thématique : POSITIONNEMENT Nature : Manuel de cours IGN Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=48674 Voir aussiRéservation
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Code-barres Cote Support Localisation Section Disponibilité 60611-01A 30.60 Livre Centre de documentation Géodésie Disponible 60611-02A 7D Livre SGM K001 Exclu du prêt Dynamic GPS height determination in the decimeter level for bathymetric applications / Robert Lemmens (1993)
Titre : Dynamic GPS height determination in the decimeter level for bathymetric applications Type de document : Monographie Auteurs : Robert Lemmens, Auteur Editeur : Delft [Pays-Bas] : Delft University of Technology Année de publication : 1993 Collection : LGR-SERIES num. 4 Importance : 110 p. Format : 21 x 30 cm Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] bathymétrie
[Termes IGN] GPS en mode différentiel
[Termes IGN] positionnement différentiel
[Termes IGN] positionnement dynamique
[Termes IGN] précision décimétrique
[Termes IGN] propagation ionosphérique
[Termes IGN] résolution d'ambiguïté
[Termes IGN] synchronisation
[Termes IGN] temps réel
[Termes IGN] trajet multipleIndex. décimale : 30.70 Navigation et positionnement Résumé : (Auteur) This research treats the feasibility of using GPS for accurate height determination of the echo sounder transducer in bathymetric applications. Positioning should be possible in the decimeter level after proper resolution of the carrier phase integer cycle ambiguity. On-the-fly ambiguity resolution techniques are used to accomplish this in a dynamic environment. To test dynamic GPS relative positioning performance, a short-baseline experiment was carried out with a wave simulator which produced an accurate reference trajectory. Using L1 carrier phase observations and C/A-code observations with a 7-satellite configuration, heights in the centimeter level were achieved after an initialization period of a few minutes. Several parts of the experiment show the importance of redundant satellites and the vulnerability of the ambiguity resolution to periodic errors and cycle slips. Dynamics in height direction of 10 cm/s do not seem to affect the ambiguity resolution process, but increase the noise level of the resulting positions. In practice baselines of a few tens of kilometers also need knowledge of atmospheric delays. Assuming these effects are well modeled, which seems feasible at the moment, and multipath is reduced, height determination is possible with an accuracy of about one decimeter for baselines of a few tens of kilometers and 1-2 decimeter for longer baselines. A high confidence level of the positions can be obtained by thorough quality control, as can be achieved by statistical testing on cycle slips and outliers. The reliability of the system will be increased by several redundant observations like simultaneously measuring 7 or more satellites, multiple reference stations, using an external timebase, etc. Finally to explore full GPS accuracy in the bathymetric survey, aspects of integrating GPS, the echo sounder and additional measurements are considered. Although relative GPS heights as obtained in this research are very well applicable in several survey applications, the decimeter accuracy of absolute heights seems still difficult to achieve when these heights are needed with respect to an absolute levelling datum, because the local relation between the levelling datum and the WGS84 ellipsoid is often not well known. Other aspects like sensor offset and time synchronization also appear to be important when integrating GPS in a bathymetric surveying system. Numéro de notice : 18207 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=55349 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 18207-01 30.70 Livre Centre de documentation Géodésie Disponible Modeling the ionosphere for an active control network of GPS stations / Y. Georgiadiou (1993)
Titre : Modeling the ionosphere for an active control network of GPS stations Type de document : Monographie Auteurs : Y. Georgiadiou, Auteur Editeur : Delft [Pays-Bas] : Delft University of Technology Année de publication : 1993 Collection : LGR-SERIES num. 7 Importance : 28 p. Format : 21 x 30 cm Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] correction ionosphérique
[Termes IGN] mesurage de phase
[Termes IGN] modèle ionosphérique
[Termes IGN] propagation ionosphérique
[Termes IGN] réseau de contrôle GPS
[Termes IGN] station GPS
[Termes IGN] traitement de données GNSSIndex. décimale : 30.60 Géodésie spatiale Résumé : (Auteur) The present study is a contribution towards the development of a regional ionospheric model based on GPS for the area covered by the proposed Active GPS Reference System (AGRS) of the Netherlands. The AGRS project is currently underway at the Faculty of Geodetic Engineering of the Delft University of Technology and is expected to support a variety of practical and scientific applications when it becomes operational.
One of the practical applications of the AGRS is related to ionospheric modelling. The parameters of an ionospheric model will be estimated in realtime using the data from the permanently observing Active Stations of the network. The intention is to make these data available to geodetic users of the AGRS, thus allowing them to increase the distance to the reference stations, e.g. for rapid static applications, without having to extend the site occupation times. The ionospheric model is scheduled to be implemented at the Centre for Processing, Storage and Distribution of data (CPSD). The CPSD will receive, process and store data from all Active Stations of the network.Numéro de notice : 18209 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=55350 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 18209-01 30.60 Livre Centre de documentation Géodésie Disponible Permanent satellite tracking networks for geodesy and geodynamics / G.L. Mader (1993)
Titre : Permanent satellite tracking networks for geodesy and geodynamics Type de document : Actes de congrès Auteurs : G.L. Mader, Éditeur scientifique Editeur : Berlin, Heidelberg, Vienne, New York, ... : Springer Année de publication : 1993 Collection : International Association of Geodesy Symposia, ISSN 0939-9585 num. 109 Conférence : IUGG 1991, 20th general Assembly and symposium GM 5 Geodynamics, UGGI - IAG 11/08/1991 24/08/1991 Vienne Autriche Importance : 193 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-540-55827-9 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] données GPS
[Termes IGN] Global Positioning System
[Termes IGN] ionosphère
[Termes IGN] orbite
[Termes IGN] positionnement par GPS
[Termes IGN] poursuite de satellite
[Termes IGN] propagation ionosphérique
[Termes IGN] réseau géodésique permanent
[Termes IGN] tectoniqueNuméro de notice : 67427 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Actes Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=37061 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 67427-01 CG.91 Livre Centre de documentation En réserve M-103 Disponible Introduction à la géodésie spatiale : Méthodes modernes en positionnement géodésique, mai 1991 / Pascal Willis (1992)PermalinkPermalinkUtilisation des mesures du système GPS pour la localisation / Kouadio Severin M'bra (1991)PermalinkDetermination of surface reflectance and estimates of atmospheric optical depth and single scattering albedo from Landsat Thematic Mapper data / J.E. Conel in International Journal of Remote Sensing IJRS, vol 11 n° 5 (May 1990)PermalinkCombination of terrestrial and GPS data for Earth deformation studies / D.B. Grant (1990)PermalinkFirst direct geodetic link between Europe, Africa and south-America with a multi station VLBI array / Gérard Petit in Bulletin géodésique, vol 63 n° 4 (décembre 1989)PermalinkAtmospheric effects on geodetic space measurements / F.K. Brunner (1988)PermalinkEin neues Korrekturmodell für Mikrowellen-Entfernungsmessungen zu Satelliten / M. Rahnemoon (1988)PermalinkZur Nutzung des Global Positioning Systems in Geodäsie und Geodynamik / H. Landau (1988)PermalinkAtmospheric corrections for remote sensing / E.M. Rollin (1985)Permalink