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Termes IGN > sciences naturelles > sciences de la Terre et de l'univers > géosciences > géophysique interne > géodésie > géodésie physique > figure de la Terre > surface de référence > géoïde > quasi-géoïde
quasi-géoïdeSynonyme(s)modèle de quasi-géoïde |
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Using models of the ocean's mean dynamic topography to identify errors in coastal geodetic levelling / M. S. Filmer in Marine geodesy, vol 37 n° 1 (March - May 2014)
[article]
Titre : Using models of the ocean's mean dynamic topography to identify errors in coastal geodetic levelling Type de document : Article/Communication Auteurs : M. S. Filmer, Auteur Année de publication : 2014 Article en page(s) : pp 47 - 64 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Nivellement
[Termes IGN] données GNSS
[Termes IGN] geoïde marin
[Termes IGN] littoral
[Termes IGN] niveau moyen des mers
[Termes IGN] nivellement géodésique
[Termes IGN] quasi-géoïde
[Termes IGN] trait de côteRésumé : (Auteur) Identifying errors (blunders and systematic errors) in coastal geodetic levelling networks has often been problematic, primarily for two reasons. First, mean sea level (MSL) at tide gauges cannot be directly compared to height differences from levelling because the geoid/quasigeoid and MSL are not parallel, being separated by the ocean's mean dynamic topography (MDT). Second, there is a the lack of redundancy at the edge of the levelling network. This article sets out a methodology to independently identify blunders and/or systematic errors (over long distances) in geodetic levelling using MDT models to account for the separation between the geoid/quasigeoid and MSL at tide gauges. This method is then tested in a case study using an oceanographic MDT model, MSL observations, GNSS data, and a quasigeoid model. The results are significant because the errors found could not be detected by standard levelling misclosure checks alone, with supplementary data from an MDT model, with cross-validation from GNSS-quasigeoid allowing their detection. In addition, it appears that an oceanographic-only MDT is as effective as GNSS and a quasigeoid model for detecting levelling errors, which could be particularly useful for countries with coastal levelling errors in their levelling networks that cannot be identified by conventional levelling closure checks. Numéro de notice : A2015-163 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/01490419.2013.868383 Date de publication en ligne : 29/10/2010 En ligne : https://doi.org/10.1080/01490419.2013.868383 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75850
in Marine geodesy > vol 37 n° 1 (March - May 2014) . - pp 47 - 64[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 230-2014011 RAB Revue Centre de documentation En réserve L003 Disponible GDQM-PL13 – the new gravimetric quasigeoid model for Poland / Malgorzata Szelachowska in Geoinformation issues, vol 6 n° 1 (2014)
[article]
Titre : GDQM-PL13 – the new gravimetric quasigeoid model for Poland Type de document : Article/Communication Auteurs : Malgorzata Szelachowska, Auteur ; Jan Krynski, Auteur Année de publication : 2014 Article en page(s) : pp 5 - 19 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] anomalie de pesanteur
[Termes IGN] collocation par moindres carrés
[Termes IGN] données GNSS
[Termes IGN] géoïde gravimétrique
[Termes IGN] Pologne
[Termes IGN] quasi-géoïdeRésumé : (auteur) The new gravimetric quasigeoid model GDQM-PL13 for Poland was determined. The 1’×1’ mean Faye anomalies, deflections of the vertical for the territory of Poland, gravity anomalies from the neighbouring countries and the EGM2008 were used as input data. The remove-compute-restore (RCR) method and the least squares collocation approach with the planar logarithmic covariance function of gravity anomalies were applied. Height anomalies computed from the GDQM-PL13 have been compared with the corresponding ones obtained from GNSS/levelling data at the stations of the POLREF, EUVN and ASG-EUPOS networks and the precise GNSS/levelling control traverse. The new quasigeoid model was also compared with the gravimetric quasigeoid model GDQ08 developed in 2008 for the area of Poland, with the EGM2008, and with the most recent global geopotential model based on GOCE data. The results of the comparison were analysed and the accuracy of the GDQM-PL13 has been assessed and discussed. Numéro de notice : A2014-764 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans En ligne : http://www.igik.edu.pl/upload/File/wydawnictwa/GI6MSJK1.pdf Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76834
in Geoinformation issues > vol 6 n° 1 (2014) . - pp 5 - 19[article]
Titre : Auvergne dataset: Testing several geoid computation methods Type de document : Article/Communication Auteurs : Pierre Valty , Auteur ; Henri Duquenne (1948-2010) , Auteur ; Isabelle Panet , Auteur 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 465 - 472 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] altitude
[Termes IGN] analyse de données
[Termes IGN] anomalie de pesanteur
[Termes IGN] Auvergne
[Termes IGN] formule de Stokes
[Termes IGN] levé gravimétrique
[Termes IGN] quasi-géoïdeRésumé : (auteur) In 2004, the French Institut Géographique National (IGN), upon the request of the steering committee of the European Gravity and Geoid Project, prepared a dataset to test geoid computation methods. It consists of a set of about 240,000 gravity points, three digital terrestrial models (an accurate one, a low-resolution one and a filtered one) and 75 GPS/levelling points to evaluate the quality of the computed geoid models (Duquenne, A data set to test geoid computation methods. In: Dergisi H (eds.), Proceedings of the 1st international symposium of the international gravity field service “gravity field of the earth”, pp 61–65, 2006). In this paper, we compared the following geoid computation methods using the Auvergne dataset: the remove-compute-restore method using the unmodified Stokes’ kernel, the deterministic (Wong and Gore) and stochastic (KTH) modifications of Stokes’ kernel. For each method, we tested different choices of the parameters (radius of integration of Stokes’ anomalies, degree of modification of Stokes’ kernel, radius of integration of terrain effect, etc.). We analysed the results in order to find out which method performs the best and how the geoid modelling method impacts the results, considering the presence of errors in the dataset. The question that this work intends to answer is whether we should put our efforts rather on the theoretical investigations of geoid modelling methodologies, or on the acquisition of gravity measurements. Numéro de notice : C2009-032 Affiliation des auteurs : LAREG (1991-2011) Thématique : POSITIONNEMENT Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : 10.1007/978-3-642-20338-1_56 Date de publication en ligne : 16/07/2011 En ligne : https://doi.org/10.1007/978-3-642-20338-1_56 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91509
contenu dans Gravity, Geoid and Earth Observation, IAG Commission 2 Gravity Field, Chania, Crete, Greece, 23-27 June 2008 / Stelios Mertikas (2010)
Titre : Quasi-Geoid of New Caledonia: Computation Results and Analysis Type de document : Article/Communication Auteurs : Pierre Valty , Auteur ; Henri Duquenne (1948-2010) , Auteur Editeur : Berlin, Heidelberg, Vienne, New York, ... : Springer Année de publication : 2010 Collection : International Association of Geodesy Symposia, ISSN 0939-9585 num. 135 Conférence : IAG 2008 Commission 2, Gravity, Geoid and Earth Observation GGEO 23/06/2008 27/06/2008 Chania Crète - Grèce Proceedings Springer Importance : pp 427 - 435 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] géoïde local
[Termes IGN] Nouvelle-Calédonie
[Termes IGN] quasi-géoïdeRésumé : (auteur) The archipelago of New Caledonia is located in the Pacific Ocean, near the New Hebrides Trench. The gravity field is extremely rough in this area, free-air gravity anomalies varying from –230 to +200 mgal. Two vain attempts to compute a geoid model in 2000 and 2004 led the Territorial Government of New Caledonia to put IGN (French National Geographic Institute) in charge of a new calculation. Gravity data were provided by several institutions (Bureau Gravimétrique International, Institut de Recherches pour le Développement, Genavire, IGN) and were of various quality, so that data cleaning has been an important stage. Using the GRAVSOFT package, height anomalies have been computed by the residual terrain method combined with Stokes integration. By comparison of the quasi-geoid with levelled GPS points on the main island, accuracy has been estimated to be better than 9 cm, which shows a significant improvement with previous solutions. A grid to convert ellipsoidal heights into heights above mean sea level has been derived from the quasi-geoid and levelled GPS points. Its accuracy is about 4.5 cm. The shifts between vertical reference systems of principal islands of the archipelago have been determined. Differences between the geoid and the mean sea level at tide gauges, and their correlation with oceanic currents have also been studied and discussed in the paper. Numéro de notice : C2008-019 Affiliation des auteurs : LAREG (1991-2011) Thématique : POSITIONNEMENT Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : 10.1007/978-3-642-10634-7_57 Date de publication en ligne : 26/02/2010 En ligne : https://doi.org/10.1007/978-3-642-10634-7_57 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91754
Titre : A data set to test geoid computation methods Type de document : Article/Communication Auteurs : Henri Duquenne (1948-2010) , Auteur Editeur : [s.l.] : [s.n.] Année de publication : 2007 Conférence : IGFS 2006, 1st International Symposium of the International Gravity Field Service 28/08/2006 01/09/2006 Istanbul Turquie OA proceedings Importance : pp 63 - 67 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] contrôle qualité
[Termes IGN] France (administrative)
[Termes IGN] quasi-géoïdeRésumé : (auteur) Upon the request of the steering committee of the European Gravity and Geoid Project, the Institut Géographique National has prepared a data set to test geoid computation methods and programs. The set consists of digital terrain models, gravity data and levelled GPS points prepared in such a way that the computation of a 3°×2° geoid is feasible. The first section describes the motivations for the preparation of this data set and the specifications. In the next two sections, the area characteristics and the data are presented. The fourth section gives an evaluation of the quality of the data set through a first solution for the quasigeoid. Finally a practical way to retrieve the data and future perspectives are outlined. Numéro de notice : C2006-039 Affiliation des auteurs : LAREG (1991-2011) Thématique : POSITIONNEMENT Nature : Communication DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102796 Documents numériques
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A data set to test geoid computation methods - pdf éditeurAdobe Acrobat PDF Recueil d'articles publiés sur le géoïde et le nivellement avec GPS de 1998 à 2004 / Henri Duquenne (2005)PermalinkEvolution de la géodésie en France / Françoise Duquenne in XYZ, n° 101 (décembre 2004 - février 2005)PermalinkComparaison and combination of a gravimetric quasigeoid with a levelled GPS data set by statistical analysis / Henri Duquenne in Physics and chemistry of the Earth, Part A: Solid Earth and Geodesy, vol 24 n° 1 (01/01/1999)PermalinkPermalinkLe modèle de quasi-géoïde français QGF96 et la surface de référence d'altitudes RAF96 / Henri Duquenne (1997)Permalink