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Estimation of phase center corrections for GLONASS-M satellite antennas / F. Dilssner in Journal of geodesy, vol 84 n° 8 (August 2010)  

Public [article]  inJournal of geodesy > vol 84 n° 8 (August 2010) . - pp 467 - 480 Titre : Estimation of phase center corrections for GLONASS-M satellite antennas Type de document : Article/Communication Auteurs : F. Dilssner, Auteur ; T. Spinger, Auteur ; Claudia Flohrer, Auteur ; John M. Dow, Auteur Année de publication : 2010 Article en page(s) : pp 467 - 480 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal [Termes IGN] antenne GLONASS [Termes IGN] centre de phase [Termes IGN] correction du signal [Termes IGN] International Terrestrial Reference Frame [Termes IGN] mesurage de phase [Termes IGN] positionnement par GNSS [Termes IGN] satellite GLONASS [Termes IGN] station GLONASS [Termes IGN] traitement du signal Résumé : (Auteur) Driven by the comprehensive modernization of theGLONASS space segment and the increased global availability of GLONASS-capable ground stations, an updated set of satellite-specific antenna phase center corrections for the current GLONASS-M constellation is determined by processing 84 weeks of dual-frequency data collected between January 2008 and August 2009 by a worldwide network of 227 GPS-only and 115 combined GPS/GLONASS tracking stations. The analysis is performed according to a rigorous combined multi-system processing scheme providing full consistency between the GPS and the GLONASS system. The solution is aligned to a realization of the International Terrestrial Reference Frame 2005. The estimated antenna parameters are compared with the model values currently used within the International GNSS Service (IGS). It is shown that the z-offset estimates are on average 7 cm smaller than the corresponding IGS model values and that the block-specific mean value perfectly agrees with the nominal GLONASS-M z-offset provided by the satellite manufacturer. The existence of azimuth-dependent phase center variations is investigated and uncertainties in the horizontal offset estimates due to mathematical correlations and yaw-attitude modeling problems during eclipse seasons are addressed. Finally, it is demonstrated that the orbit quality benefits from the updated GLONASS-M antenna phase center model and that a consistent set of satellite antenna z-offsets for GPS and GLONASS is imperative to obtain consistent GPS- and GLONASS-derived station heights. Numéro de notice : A2010-439 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-010-0381-7 Date de publication en ligne : 08/04/2010 En ligne : https://doi.org/10.1007/s00190-010-0381-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30632 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-2010081	SL	Revue	Centre de documentation	Revues en salle	Disponible

A first look at the effects of ionospheric signal bending on a globally processed GPS network / E. Petrie in Journal of geodesy, vol 84 n° 8 (August 2010)  

Public [article]  inJournal of geodesy > vol 84 n° 8 (August 2010) . - pp 491 - 499 Titre : A first look at the effects of ionospheric signal bending on a globally processed GPS network Type de document : Article/Communication Auteurs : E. Petrie, Auteur ; M. King, Auteur ; P. Moore, Auteur ; David Lavallée, Auteur Année de publication : 2010 Article en page(s) : pp 491 - 499 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal [Termes IGN] atténuation du signal [Termes IGN] correction ionosphérique [Termes IGN] propagation ionosphérique [Termes IGN] réfraction atmosphérique [Termes IGN] retard troposphérique zénithal [Termes IGN] signal GPS Résumé : (Auteur) This study provides a first attempt at quantifying potential signal bending effects on the GPS reference frame, coordinates and zenith tropospheric delays (ZTDs). To do this, we homogeneously reanalysed data from a global network of GPS sites spanning 14 years (1995.0–2009.0). Satellite, Earth orientation, tropospheric and ground station coordinate parameters were all estimated. We tested the effect of geometric bending and dTEC bending corrections, which were modelled at the observation level based, in part, on parameters from the International Reference Ionosphere 2007 model. Combined, the two bending corrections appear to have a minimal effect on site coordinates and ZTDs except for low latitude sites. Considering five days (DOY 301–305, 28 October–1 November 2001) near ionospheric maximum in detail, they affect mean ZTDs by up to ~1.7 mm at low latitudes, reducing to negligible levels at high latitudes. Examining the effect on coordinates in terms of power-spectra revealed the difference to be almost entirely white noise, with noise amplitude ranging from 0.3 mm (high latitudes) to 2.4 mm (low latitudes). The limited effect on station coordinates is probably due to the similarity in the elevation dependence of the bending term with that of tropospheric mapping functions. The smoothed z-translation from the GPS reference frame to ITRF2005 changes by less than 2 mm, though the effect combines positively with that from the second order ionospheric refractive index term. We conclude that, at the present time, and for most practical purposes, the geometric and dTEC bending corrections are probably negligible at current GPS/reference frame precisions. Numéro de notice : A2010-440 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-010-0386-2 Date de publication en ligne : 01/06/2010 En ligne : https://doi.org/10.1007/s00190-010-0386-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30633 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-2010081	SL	Revue	Centre de documentation	Revues en salle	Disponible

The effect of EGM2008-based normal, normal-orthometric and Helmert orthometric height systems on the Australian levelling network / M. Filmer in Journal of geodesy, vol 84 n° 8 (August 2010)  

Public [article]  inJournal of geodesy > vol 84 n° 8 (August 2010) . - pp 501 - 513 Titre : The effect of EGM2008-based normal, normal-orthometric and Helmert orthometric height systems on the Australian levelling network Type de document : Article/Communication Auteurs : M. Filmer, Auteur ; Will E. Featherstone, Auteur ; M. Kuhn, Auteur Année de publication : 2010 Article en page(s) : pp 501 - 513 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] altitude [Termes IGN] altitude orthométrique [Termes IGN] Australian Height Datum [Termes IGN] Australie [Termes IGN] correction orthométrique [Termes IGN] Earth Gravity Model 2008 [Termes IGN] réseau altimétrique national [Termes IGN] système de référence altimétrique Résumé : (Auteur) This paper investigates the normal-orthometric correction used in the definition of the Australian Height Datum, and also computes and evaluates normal and Helmert orthometric corrections for the Australian National Levelling Network (ANLN). Testing these corrections in Australia is important to establish which height system is most appropriate for any new Australian vertical datum. An approximate approach to assigning gravity values to ANLN benchmarks (BMs) is used, where the EGM2008-modelled gravity field is used to ‘re-construct’ observed gravity at the BMs. Network loop closures (for first- and second-order levelling) indicate reduced misclosures for all height corrections considered, particularly in the mountainous regions of south eastern Australia. Differences between Helmert orthometric and normal-orthometric heights reach 44 cm in the Australian Alps, and differences between Helmert orthometric and normal heights are about 26 cm in the same region. Normal-orthometric heights differ from normal heights by up to 18 cm in mountainous regions >2,000 m. This indicates that the quasigeoid is not compatible with normal-orthometric heights in Australia. Numéro de notice : A2010-441 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-010-0388-0 Date de publication en ligne : 11/06/2010 En ligne : https://doi.org/10.1007/s00190-010-0388-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30634 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-2010081	SL	Revue	Centre de documentation	Revues en salle	Disponible