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Auteur Liliane Bel |
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Ajouter le résultat dans votre panier Affiner la recherche Interroger des sources externesAccounting for spatiotemporal correlations of GNSS coordinate time series to estimate station velocities / Clément Benoist in Journal of geodynamics, vol 135 (April 2020)
Titre : Accounting for spatiotemporal correlations of GNSS coordinate time series to estimate station velocities Type de document : Article/Communication Auteurs : Clément Benoist Année de publication : 2020 Projets : GEODESIE / Coulot, David, Université de Paris / Clerici, Christine Article en page(s) : n° 101693 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] corrélation
[Termes IGN] covariance
[Termes IGN] données spatiotemporelles
[Termes IGN] repère de référence terrestre conventionnel
[Termes IGN] série temporelle
[Termes IGN] vitesseRésumé : (auteur) It is well known that GNSS permanent station coordinate time series exhibit time-correlated noise. Spatial correlations between coordinate time series of nearby stations are also long-established and generally handled by means of spatial filtering techniques. Accounting for both the temporal and spatial correlations of the noise via a spatiotemporal covariance model is however not yet a common practice. We demonstrate in this paper the interest of using such a spatiotemporal covariance model of the stochastic variations in GNSS time series in order to estimate long-term station coordinates and especially velocities.
We provide a methodology to rigorously assess the covariances between horizontal coordinate variations and use it to derive a simple exponential spatiotemporal covariance model for the stochastic variations in the IGS repro2 station coordinate time series. We then use this model to estimate station velocities for two selected datasets of 10 time series in Europe and 11 time series in the USA. We show that coordinate prediction as well as velocity determination from short time series are improved when using this spatiotemporal model, as compared with the case where spatiotemporal correlations are ignored.Numéro de notice : A2020-460 Affiliation des auteurs : Géodésie+Ext (mi2018-2019) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.jog.2020.101693 Date de publication en ligne : 13/01/2020 En ligne : https://doi.org/10.1016/j.jog.2020.101693 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95385
in Journal of geodynamics > vol 135 (April 2020) . - n° 101693[article]
Titre : Spatial correlations in IGS station position time series Type de document : Article/Communication Auteurs : Clément Benoist Editeur : Munich [Allemagne] : European Geosciences Union EGU Année de publication : 2018 Collection : Geophysical Research Abstracts, ISSN 1607-7962 num. 20 Conférence : EGU 2018, General Assembly 08/04/2018 13/04/2018 Vienne Autriche OA Abstracts only Note générale : EGU2018-19586 Langues : Anglais (eng) Résumé : (auteur) We present a analysis of the 2011 Mw 9.0 Tohoku-oki earthquake gravity variations in a wide space-time window surrounding the event. We identify earthquake-related gravity signals by searching for transient variations near the time of the earthquake in GRACE-reconstructed time series of gravity gradients at different spatial scales. The gravity gradients are expressed in spherical frames rotated along the radial axis in order to enhance gravity variations according to different orientations. Applied to different sets of gravity field models, our analysis allows us to evidence anomalous gravity signals starting a few months before the rupture across the regional subduction system, which cannot be explained by mass redistributions from water cycle sources around Japan nor by GRACE striping. After the rupture, the gravity variations propagate far within the Pacific and the Philippine Sea plates interiors.We further test the presence of the pre-seismic signals by also applying a statistical analysis of the gravity gradient time series, without knowledge on the consecutive rupture. Our findings show that satellite gravity brings unique information to monitor major plate boundaries, which could be used in seismic hazard assessment. Numéro de notice : C2018-073 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Poster nature-HAL : Poster-avec-CL DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91465
