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Auteur Gunnar Elgered |
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Affiner la recherche Interroger des sources externesDetermination of the local tie vector between the VLBI and GNSS reference points at Onsala using GPS measurements / Tong Ning in Journal of geodesy, vol 89 n° 7 (July 2015)
Titre : Determination of the local tie vector between the VLBI and GNSS reference points at Onsala using GPS measurements Type de document : Article/Communication Auteurs : Tong Ning, Auteur ; Rüdiger Haas, Auteur ; Gunnar Elgered, Auteur Année de publication : 2015 Article en page(s) : pp 711 - 723 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse comparative
[Termes IGN] co-positionnement
[Termes IGN] données GPS
[Termes IGN] données ITGB
[Termes IGN] écart type
[Termes IGN] point de liaison (géodésie)
[Termes IGN] point géodésique
[Termes IGN] précision millimétrique
[Termes IGN] SuèdeRésumé : (auteur) Two gimbal-mounted GNSS antennas were installed on each side of the radome-enclosed 20 m VLBI radio telescope at the Onsala Space Observatory. GPS data with a 1 Hz sampling rate were recorded for five semi-kinematic and four kinematic observing campaigns. These GPS data were analysed together with data from the IGS station ONSA with an in-house Matlab-based GPS software package, using the double-difference analysis strategy. The coordinates of the GNSS antennas on the telescope were estimated for different observation angles of the telescope, at specific epochs, and used to calculate the geodetic reference point of the telescope. The local tie vector between the VLBI and the ONSA GNSS reference points in a geocentric reference frame was hence obtained. The two different types of observing campaigns gave consistent results of the estimated local tie vector and the axis offset of the telescope. The estimated local tie vector obtained from all nine campaigns gave standard deviations of 1.5, 1.0, and 2.9 mm for the geocentric X, Y, and Z components, respectively. The result of the estimated axis offset of the VLBI telescope shows a difference of 0.3 mm, with a standard deviation of 1.9 mm, with respect to a reference value obtained by two local surveys carried out in 2002 and 2008. Our results show that the presented method can be used as a complement to the more accurate but more labour intensive classical geodetic surveys to continuously monitor the local tie at co-location stations with an accuracy of a few millimetres Numéro de notice : A2015-355 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0809-1 Date de publication en ligne : 05/04/2015 En ligne : https://doi.org/10.1007/s00190-015-0809-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76778
in Journal of geodesy > vol 89 n° 7 (July 2015) . - pp 711 - 723[article]
Titre : Advanced global navigation satellite systems tropospheric products for monitoring severe weather events and climate (GNSS4SWEC) Type de document : Article/Communication Auteurs : Guergana Guerova, Auteur ; Jonathan Jones, Auteur ; Jan Douša, Auteur ; Galina Dick, Auteur ; Siebren de Haan, Auteur ; Eric Pottiaux, Auteur ; Olivier Bock Editeur : Paris : Agence Spatiale Européenne ASE / European Space Agency ESA Année de publication : 2013 Projets : GNSS4SWEC / Conférence : ESA 2013, 4th international colloquium Scientific and fundamental aspects of the Galileo programme 04/12/2013 06/12/2013 Prague République tchèque Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] climat
[Termes IGN] données météorologiques
[Termes IGN] Global Navigation Satellite System
[Termes IGN] vapeur d'eau
[Termes IGN] variabilitéRésumé : (auteur) Global Navigation Satellite Systems (GNSS) have revolutionised positioning, navigation, and timing, becoming a common part of our everyday life. Aside from these well-known civilian and commercial applications, GNSS is now an established atmospheric observing system which can accurately sense water vapour, the most abundant greenhouse gas, accounting for 60-70 % of atmospheric warming. Water vapour is under-sampled in the current meteorological and climate observing systems, obtaining and exploiting more high-quality humidity observations is essential to weather forecasting and climate monitoring. The European COST Action ES1206 ”Advanced Global Navigation Satellite Systems tropospheric products for monitoring severe weather events and climate (GNSS4SWEC)” will address new and improved capabilities from concurrent developments in both the GNSS and the meteorological communities. For the first time, the synergy of the three GNSS systems (GPS, GLONASS and Galileo) will be used to develop new, advanced tropospheric products, exploiting the full potential of multi-GNSS water vapour estimates on a wide range of temporal and spatial scales, from real-time monitoring and forecasting of severe weather, to climate research. In addition, the COST Action ES1206 will promote the use of meteorological data in GNSS positioning, navigation, and timing services and it will stimulate knowledge transfer and data sharing throughout Europe. Numéro de notice : C2013-065 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl En ligne : https://www.researchgate.net/profile/Galina-Dick/publication/266146031_Advanced_ [...] Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101264 Documents numériques
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Titre : Retrieval of atmospheric water vapour using a ground-based single-channel microwave radiometer Type de document : Article/Communication Auteurs : P. Jarlemark, Auteur ; Gunnar Elgered, Auteur Année de publication : 2003 Article en page(s) : pp 3821 - 3837 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] atmosphère terrestre
[Termes IGN] erreur moyenne quadratique
[Termes IGN] filtre de Kalman
[Termes IGN] radiomètre à hyperfréquence
[Termes IGN] vapeur d'eauRésumé : (Auteur) Estimates of the amount of atmospheric water vapour derived from algorithms for a ground-based single-channel (21.OGHz) microwave radiometer have been investigated. Ten datasets covering 44 days were used to derive the methods and two other sets (in total 32 days) were used to assess the quality of these. It is shown how the rms estimation error can be reduced by recognizing the rapid variations in sky brightness temperatures during periods when cloud liquid is present. Data was either discarded, guided by the variability, or an adaptive Kalman filter was applied with different parameter values for different degrees of variability. The resulting estimates were compared to the estimates obtained from a dual-channel algorithm (2t.0 and 31.4GHz), which were used as reference. The amount of water vapour was represented as the 'wet delay', the excess radio path length due to the atmospheric water vapour. Applying the Kalman filter to the single-frequency estimates reduced the wet delay rms error from 20 mm to 9 and 14 mm for the two datasets. Further reduction of the rms error was achieved by the removal of data in periods with high variability; discarding about 40% of the data led to rms errors of 5 and 7 mm for the two datasets. Numéro de notice : A2003-281 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/0143116021000023952 En ligne : https://doi.org/10.1080/0143116021000023952 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22576
in International Journal of Remote Sensing IJRS > vol 24 n° 19 (October 2003) . - pp 3821 - 3837[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-03191 RAB Revue Centre de documentation En réserve L003 Exclu du prêt Satellite-Earth range measurements : Correction of the excess path length due to atmospheric water vapour by ground based microwave radiometry / Gunnar Elgered (1985)
Titre : Satellite-Earth range measurements : Correction of the excess path length due to atmospheric water vapour by ground based microwave radiometry Type de document : Rapport Auteurs : Gunnar Elgered, Auteur ; B. Ronnang, Auteur ; E. Winberg, Auteur ; J. Askne, Auteur Editeur : Göteborg [Suède] : Chalmers University of Technology Année de publication : 1985 Collection : Research report num. 147 Importance : 112 p. Format : 21 x 30 cm Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Rayonnement électromagnétique
[Termes IGN] hyperfréquence
[Termes IGN] propagation ionosphérique
[Termes IGN] propagation troposphérique
[Termes IGN] radiomètre à hyperfréquence
[Termes IGN] teneur en vapeur d'eau
[Termes IGN] water vapour radiometerIndex. décimale : 24.30 Rayonnement électromagnétique Résumé : (Auteur) This report deals with the excess delay of radio waves penetrating the neutral atmosphere of the earth, especially the delay due to water vapour, and reviews the state of the art of sounding techniques and instrumentation, in particular microwave radiometry. The physical background of the water vapour radiometer (WVR) method is presented and seven different types of WVR are described in detail. The expected accuracies of wet path delays vary with the local climate as well as with instrumental errors and the operating frequencies of the WVR. It is shown that errors in the wet path delay for zenith observations range from O.M to 0.9 cm rms for optimum WVR frequencies and instrumental errors of 0.5 K rms. Two different WVR designs - one with high accuracy and one with low cost (but less accurate) - are proposed for the ESA POPSAT system. Numéro de notice : 18239 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Rapport Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=41451 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 18239-01 24.30 Livre Centre de documentation Physique Disponible Permalink
