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Space geodesy techniques / R.T.K. Jaldehag (1995)
Titre : Space geodesy techniques : an experimental and theoretical study of antenna sources Type de document : Monographie Auteurs : R.T.K. Jaldehag, Auteur Editeur : Göteborg [Suède] : Chalmers University of Technology Année de publication : 1995 Collection : Technical report num. 276 Importance : 100 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-91-7197-168-5 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] antenne
[Termes IGN] coin réflecteur
[Termes IGN] diffusion du rayonnement
[Termes IGN] Global Positioning System
[Termes IGN] interférométrie à très grande base
[Termes IGN] mesure de précision
[Termes IGN] positionnement par GPS
[Termes IGN] positionnement par ITGB
[Termes IGN] rebond post-glaciaire
[Termes IGN] réseau géodésique permanent
[Termes IGN] Suède
[Termes IGN] SWEPOS
[Termes IGN] système de positionnement par satellites
[Termes IGN] trajet multipleIndex. décimale : 30.00 Géodésie - généralités Résumé : (Auteur) This thesis presents work associated with antenna related error sources, as well as antenna design, in space geodesy utilizing the techniques of Very-Long-Baseline Interferometry (VLBI) and the Global Positioning System (GPS). Geodetic VLBI uses large ra-dio telescopes, often in global networks observing at least a few times per year. As the number of dedicated antennas for this purpose is limited, also antennas designed for radio astronomical research are used. However, new feed systems are needed to handle the si-multaneous dual-frequency observations and the large bandwidth in geodetic VLBI. This thesis describes and numerically evaluates such a feed system. The design has the advan-tage of not interfering with existing front-end receivers of traditional Cassegrain antennas. In contrast to VLBI antenna systems, GPS antennas have low directivity in order to receive signals from the satellites in different directions simultaneously. The disadvantage with such antennas is the relatively high susceptibility to scattering from structures close to the antenna. Two studies presented in this thesis show that signal scattering from structures associated with the mounting of the antenna to the pillar and with the pillar itself, might be a significant source of error. As nearby structures are in general located below the antenna, scattering from these structures may be minimized using antennas with reduced side- and back-lobe levels. This thesis presents results from a preliminary study of two new designs of such antennas. The Swedish permanent GPS network, SWEPOS, consists of 20 stations distributed across Sweden. One of the scientific motivations for this network is to monitor crustal motions associated with postglacial rebound. This thesis describes SWEPOS, and results from almost 18 months of daily observations are presented and compared to models of postglacial rebound. The results from SWEPOS have also uncovered two major error sources. One of them is the scattering effect mentioned above. The other, which also is investigated in this thesis, is related to snow accumulated on the top of the pillars and on the radomes that covers the antennas. This accumulation appears to refract and delay the GPS signals, and thus degrade the positioning accuracy. Note de contenu : Preface
PART 1
Chapter 1 Introduction
1.1 Space Geodesy Techniques
1.2 Global Geodynamics
Chapter 2 Geodetic Very-Long-Baseline Interferometry
2.1 Background
2.2 The Main Principles
2.3 Antennas and Feeds
Chapter 3 The Global Positioning System
3.1 Background
3.2 The Main Principles
3.3 Relative Positioning Using the Carrier Phase Observables
3.4 Error Sources
3.4.1 Satellite and Receiver Clocks
3.4.2 Satellite Orbits
3.4.3 Atmospheric Delay
3.4.4 Antenna Related Effects
Chapter 4 Summary and Main Points of Thesis Papers
4.1 Main Points of Paper A
4.2 Main Points of Paper B
4.3 Main Points of Paper C
4.4 Main Points of Paper D
4.5 Main Points of Paper E
4.6 Main Points of Paper F
References
PART 2
Paper A
Paper B
Paper C
Paper D
Paper E
Paper FNuméro de notice : 18238 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=55358 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 18238-01 30.00 Livre Centre de documentation Géodésie Disponible 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
Titre : Global Positioning System : an overview : IAG symposium, Edinburgh, Scotland, August 7-8, 1989 Type de document : Actes de congrès Auteurs : Yehuda Bock, Éditeur scientifique ; Norman Leppard, Éditeur scientifique Editeur : Berlin, Heidelberg, Vienne, New York, ... : Springer Année de publication : 1990 Collection : International Association of Geodesy Symposia, ISSN 0939-9585 num. 102 Conférence : IAG 1989, 125th general meeting & IAG symposia 03/08/1989 12/08/1989 Edimbourg Royaume-Uni Importance : 447 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-0-387-97266-4 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] déformation de la croute terrestre
[Termes IGN] DORIS
[Termes IGN] Global Positioning System
[Termes IGN] GPS en mode cinématique
[Termes IGN] positionnement cinématique
[Termes IGN] trajet multipleIndex. décimale : CG1989 Actes de congrès en 1989 Numéro de notice : 67631 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Actes DOI : 10.1007/978-1-4615-7111-7 En ligne : https://doi.org/10.1007/978-1-4615-7111-7 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=37127 ContientRéservation
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Code-barres Cote Support Localisation Section Disponibilité 67631-01 CG.89 Livre Centre de documentation En réserve M-103 Disponible Multipath and GPS / C. Bosloper (1990)
Titre : Multipath and GPS : short periodic components of the time variation of the differential dispersive delay Type de document : Monographie Auteurs : C. Bosloper, Auteur Editeur : Kensington [Australie] : University of New South Wales Année de publication : 1990 Collection : Unisurv Report num. S-39 Importance : 204 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-0-85839-057-7 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] GPS en mode différentiel
[Termes IGN] propagation du signal
[Termes IGN] signal GPS
[Termes IGN] trajet multipleIndex. décimale : 30.61 Systèmes de Positionnement par Satellites du GNSS Numéro de notice : 63990 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=61248 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 63990-01 30.61 Livre Centre de documentation Géodésie Disponible On principles, methods and recent advances in studies towards a GPS-based control system for geodesy and geodynamics / D. Delikaraoglou (1989)
Titre : On principles, methods and recent advances in studies towards a GPS-based control system for geodesy and geodynamics Type de document : Monographie Auteurs : D. Delikaraoglou, Auteur Editeur : Washington : National Aeronautics and Space Administration NASA Année de publication : 1989 Collection : NASA Technical Memorandum Importance : 105 p. Format : 21 x 30 cm Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] erreur systématique
[Termes IGN] interférométrie à très grande base
[Termes IGN] orbitographie
[Termes IGN] positionnement différentiel
[Termes IGN] positionnement par GPS
[Termes IGN] télémétrie laser sur satellite
[Termes IGN] trajet multipleIndex. décimale : 30.61 Systèmes de Positionnement par Satellites du GNSS Numéro de notice : 18486 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=55404 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 18486-01 30.61 Livre Centre de documentation Géodésie Disponible The GPS microstrip antenna properties, reduction of multipath contamination and other interference by an RF absorbent ground plane / S. Tallqvist (04/11/1985)Permalink