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Three-Corner Hat for the assessment of the uncertainty of non-linear residuals of space-geodetic time series in the context of terrestrial reference frame analysis / Claudio Abbondanza in Journal of geodesy, vol 89 n° 4 (April 2015)  

Public [article]  inJournal of geodesy > vol 89 n° 4 (April 2015) . - pp 313-329 Titre : Three-Corner Hat for the assessment of the uncertainty of non-linear residuals of space-geodetic time series in the context of terrestrial reference frame analysis Type de document : Article/Communication Auteurs : Claudio Abbondanza, Auteur ; Zuheir Altamimi , Auteur ; T.M. Chin, Auteur ; Richard S. Gross, Auteur ; Michael B. Heflin, Auteur ; J. W. Parker, Auteur ; X. Wu, Auteur Année de publication : 2015 Article en page(s) : pp 313-329 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux [Termes IGN] co-positionnement [Termes IGN] corrélation temporelle [Termes IGN] estimation de cohérence [Termes IGN] hauteur ellipsoïdale [Termes IGN] incertitude de position [Termes IGN] International Terrestrial Reference Frame [Termes IGN] série temporelle [Termes IGN] signal GPS Résumé : (auteur) We discuss the application of the Three-Corner Hat (TCH) to time series of space-geodetic station position residuals with the purpose of characterizing the uncertainties of GPS, VLBI, SLR, DORIS for the International Terrestrial Reference Frame (ITRF) determination. Adopting simulations, we show that, in the absence of time-correlated errors, TCH is able to fully recover the nominal uncertainties of groups of observations whose intrinsic precisions are remarkably dissimilar to one another, as is the case for the space-geodetic techniques. When time-correlated errors are predominant, as it happens with GPS, TCH is affected by the increased variance of the observations and its estimates are positively biased. TCH applied to 16 ITRF co-located sites confirms that GPS, albeit affected by time-correlated errors, is the most precise of the space-geodetic techniques. GPS median uncertainties are 1.1, 1.2 and 2.8 mm, for the north, east and height component, respectively. VLBI performs particularly well in the horizontal component, the median uncertainties being ≈2 mm. The height component is ∼3 times larger than the GPS one. SLR and DORIS median uncertainties exceed by far the 7 mm level on all of the three components. Comparing TCH results with station position repeatabilities, we find that the two metrics are in striking agreement for VLBI and DORIS, but not for SLR and GPS. The inconsistencies between TCH and station repeatabilities for co-located GPS and SLR point to the presence of either specific station-dependent biases or low-quality co-locations. Scaling factors derived adopting the ratio between TCH and median formal errors on the positions suggest the station position covariances have to be up-scaled for VLBI, SLR, DORIS and down-scaled for GPS. Numéro de notice : A2015-340 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0777-x Date de publication en ligne : 18/11/2014 En ligne : https://doi.org/10.1007/s00190-014-0777-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76709 [article]