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interférométrie à très grande baseSynonyme(s)vlbi Interférométrie à très longue base |
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Titre : Combinaison de techniques de géodésie spatiale : contributions aux réalisations des systèmes de référence et à la détermination de la rotation de la Terre Type de document : Thèse/HDR Auteurs : Arnaud Pollet , Auteur ; Nicole Capitaine, Directeur de thèse ; David Coulot , Encadrant Editeur : Paris, Meudon et Nançay : Observatoire de Paris Année de publication : 2011 Importance : 209 p. Format : 21 x 30 cm Note générale : bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] données DORIS
[Termes IGN] données GPS
[Termes IGN] données ITGB
[Termes IGN] données TLS (télémétrie)
[Termes IGN] GINS
[Termes IGN] orientation de la Terre
[Termes IGN] repère de référence
[Termes IGN] retard troposphérique zénithal
[Termes IGN] rotation de la Terre
[Termes IGN] série temporelle
[Termes IGN] station permanenteIndex. décimale : THESE Thèses et HDR Résumé : (auteur) Les travaux de cette thèse portent sur les combinaisons d’observations obtenues par les techniques de géodésie spatiale DORIS, GPS, SLR et VLBI. Cette approche de combinaison au niveau des observations fait actuellement l’objet de différentes expériences, notamment dans le cadre du groupe de travail COL (Combination at the Observation Level) de l’IERS. Afin d’obtenir les meilleurs résultats possibles, la définition d’un repère terrestre combiné homogène est nécessaire. Je me suis donc attaché ici à obtenir la meilleure réalisation possible du système de référence terrestre. Dans ce but, différentes approches ont été testées. Un nouveau modèle de combinaison a été développé, qui permet l’obtention d’un repère terrestre homogène. L’apport des rattachements locaux entre instruments co-localisés et leur impact sur l’homogénéité des repères combinés hebdomadaires ont également été analysés. Pour cela, j’ai adapté une méthode de traitement des données GPS par sous-réseaux afin de disposer d’un réseau GPS dense et d’un grand nombre de stations co-localisées. Pour renforcer les liens entre les techniques, l’utilisation de délais troposphériques zénithaux communs et de liens spatiaux via des satellites multi-techniques a été étudié et j’ai démontré leur pertinence. Enfin, une telle combinaison a été réalisée sur l’année 2005. Ce travail a ainsi permis d’obtenir des séries temporelles d’EOP et de positions de stations bénéficiant de l’homogénéité des traitements réalisés et de la meilleure résolution temporelle (notamment en ce qui concerne les EOP) et exactitude de chacune des quatre techniques utilisées dans la combinaison. Numéro de notice : 14860 Affiliation des auteurs : LAREG (1991-2011) Thématique : POSITIONNEMENT Nature : Thèse française Note de thèse : Thèse : : St Mandé, IGN : 2011 Organisme de stage : LAREG (IGN) nature-HAL : Thèse DOI : sans En ligne : https://hal.science/tel-00069016v1 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75787
Titre : Impact of a priori gradients on VLBI-derived terrestrial reference frames Type de document : Article/Communication Auteurs : Johannes Böhm , Auteur ; H. Spicakova, Auteur ; L. Urquhart, Auteur ; et al., Auteur Editeur : Bonn : Universität Bonn Année de publication : 2011 Collection : Schriftenreihe des Instituts für Geodäsie und Geoinformation, ISSN 2699-6685 num. 22 Conférence : EVGA 2011, 20th working meeting of the European VLBI Group for Geodesy and Astrometry 29/03/2011 30/03/2011 Bonn Allemagne OA proceedings Importance : pp 128 - 132 Format : 21 x 30 cm Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] analyse diachronique
[Termes IGN] données ITGB
[Termes IGN] gradient de troposphère
[Termes IGN] International Terrestrial Reference FrameRésumé : (Auteur) We compare the influence of two different a priori gradient models on the terrestrial reference frame (TRF) as determined from Very Long Baseline Interferometry (VLBI) observations. One model has been determined by vertical integration over horizontal gradients of refractivity as derived from data of the Goddard Data Assimilation Office (DAO), whereas the second model (APG) has been determined by ray-tracing through monthly mean pressure level re-analysis data of the European Centre for Medium-Range Weather Forecasts. We compare VLBI solutions from 1990.0 to 2011.0 with fixed DAO and APG gradients to a solution with gradients being estimated, and we find better agreement of station coordinates when fixing DAO gradients compared to fixing APG gradients. As a consequence, we recommend that gradients are constrained to DAO gradients, in particular in the early years of VLBI observations (up to about 1990), when the number of stations per session is small and the sky distribution is far from uniform. Later than 1990, the gradients can be constrained loosely and the a priori model is of minor importance. Numéro de notice : C2011-052 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Communication DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=64322 Documents numériques
en open access
14256_evga2011_boehm.pdfAdobe Acrobat PDF
Titre : International VLBI Service for Geodesy and Astrometry 2010 annual report Type de document : Rapport Auteurs : Dirk Behrend, Éditeur scientifique ; Karen D. Baver, Éditeur scientifique Editeur : Washington : National Aeronautics and Space Administration NASA Année de publication : 2011 Importance : 350 p. Format : 21 x 28 cm Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] astrométrie
[Termes IGN] géodynamique
[Termes IGN] interférométrie à très grande base
[Termes IGN] orientation de la Terre
[Termes IGN] radioastronomie
[Termes IGN] repère de référence
[Termes IGN] rotation de la Terre
[Termes IGN] système de référence céleste
[Termes IGN] système de référence mondialNuméro de notice : 14744 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Rapport d'activité En ligne : http://ivscc.gsfc.nasa.gov/publications/annualreport.html Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=40607
Titre : Sub-daily parameter estimation in VLBI data analysis : Dissertation carried out in order to obtain the academic degree ”doctor of the technical sciences” under the supervision of o.Univ.-Prof. Dipl.-Ing. Dr.techn. Harald Schuh, presented at the Vienna University of Technology, Faculty of Mathematics and Geoinformation, Institute of Geodesy and Geophysics Type de document : Thèse/HDR Auteurs : Kamil Teke, Auteur ; Harald Schuh, Directeur de thèse Editeur : Vienne [Autriche] : Vienna University of Technology Année de publication : 2011 Importance : 275 p. Format : 21 x 30 cm Note générale : Bibliographie
thèse étrangèreLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse comparative
[Termes IGN] compensation par moindres carrés
[Termes IGN] données ITGB
[Termes IGN] estimation des paramètres
[Termes IGN] estimation statistique
[Termes IGN] horloge
[Termes IGN] propagation troposphérique
[Termes IGN] rotation de la TerreIndex. décimale : THESE Thèses et HDR Résumé : (Auteur) The main objective of the work carried out within the scope of this thesis is the contribution to the VLBI2010 project of the International Very Long Baseline Interferometry (VLBI) Service for Geodesy and Astrometry (IVS) by means of developing a parameter estimation module (vie lsm) of Vienna VLBI Software (VieVS) which is capable of estimating accurate sub-daily VLBI geodetic parameters. The vie lsm module is based on the classical Gauss Markoff Least-Squares (LS) adjustment method by using continuous piece-wise linear offset (CPWLO) functions which are estimated at unique epochs, e.g. at integer hours, or at integer fractions or integer multiples of integer hours. The interval for CPWLO modelling of the parameters is usually set to values between one day to five minutes.
To investigate the sub-daily tidal motions of the VLBI antennas during IVS-CONT05, hourly CPWLO Terrestrial Reference Frame (TRF) coordinates of the antennas were estimated. Although all tidal displacements are computed from state-of-the-art geophysical models and reduced from the observations a priori to the adjustment, the radial amplitudes from the estimated hourly antenna coordinates can reach up to 1 cm (Kokee, HartRAO, Gilcreek, Westford, Svetloe, and Wettzell). To analyze the high frequency (sub-daily) Earth rotation parameter (HF-ERP) estimates of VieVS during IVS-CONT08, hourly CPWLO ERP were estimated. The Fourier spectra of the hourly VLBI and Global Positioning System (GPS) ERP estimates and the HFERP models during IVS-CONT08 are in a good agreement at prograde and retrograde 12 hours both for length of day (LOD) and polar motion. However, at 24 hour prograde polar motion the amplitude from GPS is larger by about 100 ìas than VLBI and larger by about 160 ìas than HF-ERP models. Additionally, VieVS LOD and polar motion estimates are noisier than from GPS. This may be due to the fact that no relative constraints between the CPWLO ERP estimates in VLBI analysis were introduced. The estimation of hourly source coordinates was rather intended as test study. As long as hourly CPWLO coordinates of two sources are estimated and the remaining sources are fixed to their a priori Celestial Reference Frame (CRF) i coordinates, parametrization of the Earth Orientation Parameters (EOP) is not critical for the estimated source coordinates. However, investigations on this issue need to be carried out in future, e.g. a lot can be learned from correlations between hourly source coordinates and the observation geometry.
The second aim of this thesis, which is also a very good test of the CPWLO estimates of troposphere zenith delays and gradients, is the contribution to combination studies in the framework of the Global Geodetic Observing System (GGOS) of the International Association of Geodesy (IAG) by multi-technique comparison of zenith total delays (ZTD) and troposphere gradients. In the scope of this issue, VLBI VieVS estimates of troposphere ZTD and gradients during IVS-CONT08 were compared with those derived from observations with the GPS, Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS), and water vapor radiometers (WVR) co-located with the VLBI radio telescopes. ZTD and gradients estimated by space geodetic techniques are compared to those computed by ray-tracing through the profiles of various Numerical Weather Models (NWM), such as the European Centre for Medium-Range Weather Forecasts (ECMWF) (all sites), the Japan Meteorological Agency (JMA) and Cloud Resolving Storm Simulator (CReSS) (Tsukuba in Japan), and the High Resolution Limited Area Model (HIRLAM) (European sites). The best inter space geodetic technique agreement of ZTD during IVS-CONT08 is found between the combined IVS and the International GNSS Service (IGS) solutions with a mean standard deviation of about 6 mm over all sites, whereas the agreement with numerical weather models is between 6 and 20 mm. The standard deviations are generally larger at low latitude sites because of higher humidity, and the latter is also the reason why the standard deviations are larger at northern hemisphere stations during IVS-CONT08 in comparison to IVS-CONT02 which was observed in October 2002. The assessment of the troposphere gradients from the different techniques is not as clear because of different time intervals, different estimation properties, or different observable. However, the best inter-technique agreement is found between the IVS combined gradients and the GPS solutions with standard deviations between 0.2 mm and 0.7 mm. As mentioned before all the comparisons and validation tests on the troposphere products during IVS-CONT08 presented in this thesis provide important information with respect to the planned combination and integration of various observing techniques in the framework of the Global Geodetic Observing System (GGOS) of the International Association of Geodesy (IAG).Note de contenu : 1 Introduction
1.1 VLBI Basics
1.2 Contribution of the thesis and research objectives
1.3 Outline of the thesis
2 VLBI delay model
2.1 Gravitational delay
2.2 Vacuum delay and geometric delay
2.3 Partial derivatives of the VLBI delay model with respect to EOP, antenna and source coordinates
2.4 Continuous piece-wise linear offset (CPWLO) functions for sub-daily parameter estimation
3 Least Squares (LS) Adjustment
3.1 Gauss Markoff model
3.2 Constraining parameters
3.3 Free Network Solution
3.4 Stacking normal equation systems
3.5 Parameter estimation in vie lsm
3.5.1 Handling outliers
4 VLBI clock error
4.1 Modelling and estimating VLBI clock errors based on CPWLO functions
4.1.1 Clock error model
4.1.2 Determining and modelling clock breaks
4.1.3 Clock break error on the VLBI observations and its propagation on estimated VLBI parameters
4.2 Frequency stabilities of the VLBI clocks
5 Troposphere delay
5.1 Troposphere mapping functions
5.2 Troposphere gradients
5.3 Troposphere delays in VieVS
6 Multi-technique comparison of troposphere zenith delays and gradients during IVSCONT
6.1 IVS-CONT08 co-located sites, techniques and solutions
6.1.1 Space geodetic solutions
6.1.2 Water Vapor Radiometer (WVR)
6.1.3 Numerical Weather Models (NWM)
6.2 Agreement criteria for the comparisons and troposphere ties
6.3 Intra-technique comparisons of ZTD
6.4 Inter-technique comparisons of ZTD
6.5 Comparison with IVS-CONT02
6.6 Troposphere gradients comparisons
7 VLBI Baseline Length Repeatability Tests of IVS-R1 and -R4 Sessions
7.1 IVS-R1 and -R4 sessions
7.2 Comparison of baseline length repeatabilities derived from different mapping functions and cut-off angles
8 Analyses of the TRF, EOP, and CRF VLBI estimates
8.1 Analysis of the tidal motions at VLBI antennas: Sub-daily CPWLO coordinate estimates versus tide models during IVS-CONT05
8.2 Analyses of the sub-daily ERP during IVS-CONT08: model versus observations
8.3 Analyses of the sub-daily coordinate time series of several defining sources in ICRF2 during IVS-CONT08
9 Conclusions and OutlookNuméro de notice : 14249 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère DOI : sans En ligne : https://repositum.tuwien.at/handle/20.500.12708/982 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=62653 The crustal dynamics data information system: a resource to support scientific analysis using space geodesy / Carey E. Noll in Advances in space research, vol 45 n° 12 (15/06/2010)
[article]
Titre : The crustal dynamics data information system: a resource to support scientific analysis using space geodesy Type de document : Article/Communication Auteurs : Carey E. Noll, Auteur Année de publication : 2010 Article en page(s) : pp 1421 - 1440 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] déformation de la croute terrestre
[Termes IGN] données DORIS
[Termes IGN] données géodésiques
[Termes IGN] données GNSS
[Termes IGN] données ITGB
[Termes IGN] données multisources
[Termes IGN] géodésie spatiale
[Termes IGN] Global Geodetic Observing System
[Termes IGN] métadonnéesRésumé : (Auteur) Since 1982, the Crustal Dynamics Data Information System (CDDIS) has supported the archive and distribution of geodetic data products acquired by the National Aeronautics and Space Administration (NASA) as well as national and international programs. The CDDIS provides easy, timely, and reliable access to a variety of data sets, products, and information about these data. These measurements, obtained from a global network of nearly 650 instruments at more than 400 distinct sites, include DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite), GNSS (Global Navigation Satellite System), SLR and LLR (Satellite and Lunar Laser Ranging), and VLBI (Very Long Baseline Interferometry). The CDDIS data system and its archive have become increasingly important to many national and international science communities, particularly several of the operational services within the International Association of Geodesy (IAG) and its observing system the Global Geodetic Observing System (GGOS), including the International DORIS Service (IDS), the International GNSS Service (IGS), the International Laser Ranging Service (ILRS), the International VLBI Service for Geodesy and Astrometry (IVS), and the International Earth rotation and Reference frame Service (IERS). Investigations resulting from the data and products available through the CDDIS support research in many aspects of Earth system science and global change. Each month, the CDDIS archives more than one million data and derived product files totaling over 90 Gbytes in volume. In turn, the global user community downloads nearly 1.2 Tbytes (over 10.5 million files) of data and products from the CDDIS each month. The requirements of analysts have evolved since the start of the CDDIS; the specialized nature of the system accommodates the enhancements required to support diverse data sets and user needs. This paper discusses the CDDIS, including background information about the system and its user communities, archive contents, available metadata, and future plans. Numéro de notice : A2010-360 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2010.01.018 En ligne : https://doi.org/10.1016/j.asr.2010.01.018 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30554
in Advances in space research > vol 45 n° 12 (15/06/2010) . - pp 1421 - 1440[article]Asymmetric tropospheric delays from numerical weather models for UT1 determination from VLBI Intensive sessions on the baseline Wettzell–Tsukuba / Johannes Böhm in Journal of geodesy, vol 84 n° 5 (May 2010)PermalinkPermalinkSpace-time reference systems for monitoring global change and for precise navigation / Axel Nothnagel (2010)PermalinkLocal effects of redundant terrestrial and GPS-based tie vectors in ITRF-like combinations / Claudio Abbondanza in Journal of geodesy, vol 83 n° 11 (November 2009)PermalinkLocal effects of redundant terrestrial and GPS-based tie vectors in ITRF-like combinations / Claudio Abbondanza in Journal of geodesy, vol 83 n° 11 (November 2009)PermalinkPermalinkPermalinkThe impact of errors in polar motion and nutation on UT1 determinations from VLBI Intensive observations / Axel Nothnagel in Journal of geodesy, vol 82 n° 12 (December 2008)PermalinkOn the accuracy assessment of celestial reference frame realizations / Z. Malkin in Journal of geodesy, vol 82 n° 6 (June 2008)PermalinkPermalink