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Some considerations on significance analysis for deformation detection via frequentist and Bayesian tests / F. Sacerdote in Journal of geodesy, vol 84 n° 4 (April 2010)  

Public [article]  inJournal of geodesy > vol 84 n° 4 (April 2010) . - pp 233 - 242 Titre : Some considerations on significance analysis for deformation detection via frequentist and Bayesian tests Type de document : Article/Communication Auteurs : F. Sacerdote, Auteur ; N. Cazzaniga, Auteur ; V. Tornatore, Auteur Année de publication : 2010 Article en page(s) : pp 233 - 242 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] analyse de données [Termes IGN] classification bayesienne [Termes IGN] déformation géométrique Résumé : (Auteur) The Bayesian approach to significance testing, that makes use of prior information, has been studied in the last years, particularly to allow the detection of deformations which are small with respect to measurement errors from repeated surveys. Some investigations showed up to now that, under particular conditions concerning both the parameters of the prior distribution and the structure of the control network, Bayesian tests give stronger results than tests based on the frequentist approach, with regard to the detectability of deformations. In the present paper, after illustrating the essential developments and the most relevant results of previous works, new analytical developments and numerical simulations are carried out, to illustrate some critical aspects and advantages of the frequentist and Bayesian methods. It is shown, starting from simple examples involving only Gaussian and truncated Gaussian distributions and from a simplified formulation of the prior deformation model, that the testing procedures based on the frequentist approach, which do not introduce any a priori information, are in many cases of practical interest insensitive to internal consistencies of the displacements (e.g., to the fact that they have a common direction). It is also illustrated that the introduction of prior information, even in a non Bayesian context, more easily allows the detection of little displacements. Besides it is noted that in some cases Bayesian tests detect displacements in the presence of observed non-coherent movements, even if prior probability densities describing coherent movements are introduced. Copyright Springer Numéro de notice : A2010-151 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-009-0360-z Date de publication en ligne : 09/12/2009 En ligne : https://doi.org/10.1007/s00190-009-0360-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30346 [article]

Exemplaires(1)

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266-2010041	MANQUANT	Revue	Centre de documentation	Indéterminé	Disponible

The impact of radio source structure on European geodetic VLBI measurements / V. Tornatore in Journal of geodesy, vol 81 n° 6-8 (June - August 2007)  

Public [article]  inJournal of geodesy > vol 81 n° 6-8 (June - August 2007) . - pp 469 - 478 Titre : The impact of radio source structure on European geodetic VLBI measurements Type de document : Article/Communication Auteurs : V. Tornatore, Auteur ; Patrick Charlot, Auteur Année de publication : 2007 Article en page(s) : pp 469 - 478 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] données ITGB [Termes IGN] European VLBI network [Termes IGN] interférométrie à très grande base [Termes IGN] rayonnement cosmique Résumé : (Auteur) European geodetic very long baseline interferometry (VLBI) sessions (also known as EUROPE sessions) have been carried out on a regular basis for the past 15 years to study relative crustal motions within Europe. These sessions are based on observations of extragalactic radio sources, which serve as distant fiducial marks to establish an accurate and stable celestial reference frame for long-term geodetic measurements. The radio sources, however, are not always point-like on milliarcsecond scales, as VLBI imaging has revealed. In this work, we quantify the magnitude of the expected effect of intrinsic source structure on geodetic bandwidth synthesis delay VLBI measurements for a subset of 14 sources regularly observed during the EUROPE sessions. These sources have been imaged at both X-band (8.4 GHz) and S-band (2.3 GHz) based on dedicated observations acquired with the European VLBI Network (EVN) in November 1996. The results of this calculation indicate that the reference source 0457+024 causes significant structural effects in measurements obtained on European VLBI baselines (about 10 picoseconds on average), whereas most of the other sources produce effects that are only occasionally larger than a few picoseconds. Applying the derived source structure models to the data of the EUROPE5-96 session carried out at the same epoch as the EVN experiment shows no noticeable changes in the estimated VLBI station locations. Copyright Springer Numéro de notice : A2007-242 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-007-0146-0 En ligne : https://doi.org/10.1007/s00190-007-0146-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28605 [article]

Exemplaires(2)

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266-07062	RAB	Revue	Centre de documentation	En réserve L003	Disponible
266-07061	RAB	Revue	Centre de documentation	En réserve L003	Disponible