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Auteur Nicolas Bergeot |
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Affiner la recherche Interroger des sources externesComparison of regional and global GNSS positions, velocities and residual time series / Juliette Legrand (2012)
Titre : Comparison of regional and global GNSS positions, velocities and residual time series Type de document : Article/Communication Auteurs : Juliette Legrand, Auteur ; Nicolas Bergeot, Auteur ; Carine Bruyninx, Auteur ; Guy Wöppelmann Editeur : Berlin, Heidelberg, Vienne, New York, ... : Springer Année de publication : 2012 Collection : International Association of Geodesy Symposia, ISSN 0939-9585 num. 136 Conférence : IAG 2009 Symposium, Geodesy for Planet Earth 31/08/2009 04/09/2009 Buenos Aires Argentine Proceedings Springer Importance : pp 95 - 103 Format : 16 x 24 cm Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] European Terrestrial Reference Frame
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] résidu
[Termes IGN] retard troposphérique zénithal
[Termes IGN] série temporelleRésumé : (auteur) More than 10 years (1996–2008) of weekly GPS solutions of 299 globally distributed stations have been used to quantify the impact of the reference frame definition and especially the size of the network on the estimated station positions, velocities, and residual position time series. For that purpose, weekly regional solutions (covering the European region) and global solutions have been respectively stacked to obtain regional and global station positions, velocities, and residual position time series. In both cases, the estimated long-term solutions have been tied to the ITRF2005 under minimal constraints using a selected set of reference stations. This study shows that: (1) regional position and velocity solutions can present biases with respect to each other and to global solutions, while in comparison, global solutions are much more stable; (2) the obtained residual position time series are affected by the size of the network with significantly reduced periodic signals in the regional networks, e.g. a 27% reduction of the annual signals in the height component. Numéro de notice : C2009-063 Affiliation des auteurs : LAREG+Ext (1991-2011) Thématique : POSITIONNEMENT Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : 10.1007/978-3-642-20338-1_12 Date de publication en ligne : 26/07/2011 En ligne : https://doi.org/10.1007/978-3-642-20338-1_12 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102021
Titre : Results and comparisons of a local and a regional reprocessed GNSS network Type de document : Article/Communication Auteurs : Juliette Legrand, Auteur ; Carine Bruyninx, Auteur ; Nicolas Bergeot, Auteur Année de publication : 2010 Article en page(s) : pp 257 - 266 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] analyse comparative
[Termes IGN] Belgique
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] polyèdre
[Termes IGN] réseau géodésique localRésumé : (Auteur) This paper compares the results obtained from two homogenously reprocessed GNSS networks which are tied to a global conventional frame, namely the ITRF2005, using minimal constraints. The first network (222 stations) comprises the full EUREF Permanent Network (EPN). The second network is a smaller local network consisting of the national dense Belgian network and 38 EPN stations located in and around Belgium. We show that in reason of the network effect, it is impossible to mix the results of both cumulative solutions. Indeed, the position differences between both networks tied to the ITRF2005 using minimal constraints can reach 6.3 mm for the horizontal and 9.6 mm for the vertical. For the velocities, the differences reach 0.5 mm/yr for the horizontal and 2.4 mm/yr for the vertical. In order to mitigate these differences and to obtain a consistent set of station positions and velocities, the two solutions were combined on a weekly basis and then the combined weekly solutions were stacked to obtain a cumulative solution expressed in ITRF2005. The results demonstrate that the network effect on the local solution can be eliminated. This approach is valid thanks to the agreement between the weekly polyhedrons of both solutions as the same data analysis strategy was applied during both reprocessing. Numéro de notice : A2010-599 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31343
in Bulletin of geodesy and geomatics BGG > vol 69 n° 2 - 3 (December 2010) . - pp 257 - 266[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 013-2010021 RAB Revue Centre de documentation En réserve L003 Disponible
Titre : Impact of regional reference frame definition on geodynamic interpretations Type de document : Article/Communication Auteurs : Juliette Legrand, Auteur ; Nicolas Bergeot, Auteur ; Carine Bruyninx, Auteur ; Guy Wöppelmann Année de publication : 2010 Article en page(s) : pp 116 - 122 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] champ de vitesse
[Termes IGN] données GNSS
[Termes IGN] Europe (géographie physique)
[Termes IGN] géodynamique
[Termes IGN] International Terrestrial Reference FrameRésumé : (auteur) Ten years (1997–2006) of weekly GNSS solutions of 205 globally distributed stations have been used to investigate the impact of the reference frame definition on the estimated station velocities. For that purpose, weekly regional solutions (covering the European region) and global solutions have been, respectively, stacked to obtain regional and global velocity fields. In both cases, the estimated long-term solutions (station positions and velocities) were tied to the ITRF2005 under minimal constraints using a selected set of reference stations. Several sets of global and regional reference stations were tested to evaluate first the impact of the reference frame definition on the global and regional velocity fields and later the impact on the derived geodynamic interpretations.
Results confirm that the regional velocity fields show systematic effects with respect to the global velocity field with differences reaching up to 1.3 mm/year in the horizontal and 2.9 mm/year in the vertical depending on the geographical extent of the network and the chosen set of regional reference stations.
In addition, the estimations of the Euler pole for Western Europe differ significantly when considering a global or a regional strategy. After removing the rigid block rotation, the residual velocity fields show differences which can reach up to 0.8 mm/year in horizontal component.
In Northern Europe, the vertical ground motion is dominated by the Glacial Isostatic Adjustment (GIA). A proper modeling of this effect requires sub-mm/year precision for the vertical velocities for latitudes below 56°. We demonstrate that a profile of vertical velocities shows significant discrepancies according to the reference frame definition strategy. In the case of regional solutions, the vertical modeling does not predict any subsidence around 52° as predicted by the global solution and previous studies.
In summary, we evidence the limitation of regional networks to reconstruct absolute velocity fields and conclude that when geodynamics require the highest precisions for the GNSS-based velocities, a global reference frame definition is more reliable.Numéro de notice : A2010-638 Affiliation des auteurs : IGN+Ext (1940-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.jog.2009.10.002 Date de publication en ligne : 14/10/2009 En ligne : https://doi.org/10.1016/j.jog.2009.10.002 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89892
in Journal of geodynamics > vol 49 n° 3-4 (April 2010) . - pp 116 - 122[article]
Titre : Horizontal and vertical interseismic velocity fields in the Vanuatu subduction zone from GPS measurements: Evidence for a central Vanuatu locked zone Type de document : Article/Communication Auteurs : Nicolas Bergeot, Auteur ; Marie-Noëlle Bouin Année de publication : 2009 Article en page(s) : 20 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] champ de vitesse
[Termes IGN] coordonnées GPS
[Termes IGN] subduction
[Termes IGN] tectonique des plaques
[Termes IGN] VanuatuRésumé : (auteur) We analyzed interseismic velocity fields along the Vanuatu arc subduction zone from more than 45 GPS station measurements spanning 15 years. Convergence with respect to the Australian plate (AP) is normal to the trench, with amplitudes that vary greatly from a maximum of 170 mm a−1 at Vanikoro to 27 mm a−1 facing the D'Entrecasteaux Ridge (DER). Motions expressed relative to the Pacific plate (PP) highlight arc segmentation. Both the northern and southern segments undergo back‐arc spreading in a roughly NE‐SW direction, rotating anticlockwise and clockwise, respectively, while the central block moves eastward at a faster rate with respect to the PP than to the AP. More convergence is therefore accommodated at the eastern bound of the arc than at the Vanuatu trench. A right lateral strike‐slip movement (26 ± 1 mm a−1) along a zone normal to the trench (direction N70°) is necessary to accommodate the rate variation between the central and southern parts of the arc. Horizontal and vertical rates indicate partitioning between Malekula–southernmost Santo and central‐northern Santo blocks. Simple elastic modeling of the interseismic stage deformation gives locked zone characteristics (25° dip and 50 km width) and a 54 mm a−1 long‐term convergence rate between the AP and the central part of the Vanuatu arc from GPS horizontal and vertical velocities estimated south of the DER. The modeling does not fit the observed velocities facing the DER, probably because it does not account for the inelastic deformation associated with buoyant ridge subduction and back‐arc thrusting. Numéro de notice : A2009-586 Affiliation des auteurs : IGN+Ext (1940-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1029/2007JB005249 Date de publication en ligne : 23/06/2009 En ligne : https://doi.org/10.1029/2007JB005249 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90613
in Journal of geophysical research : Solid Earth > Vol 114 n° B6 (June 2009) . - 20 p.[article]Documents numériques
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Horizontal and vertical interseismic velocity fields ... - pdf éditeurAdobe Acrobat PDF
