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Assessment of inner reliability in the Gauss-Helmert model / Andreas Ettlinger in Journal of applied geodesy, vol 14 n° 1 (January 2020)  

Public [article]  inJournal of applied geodesy > vol 14 n° 1 (January 2020) . - pp 13 - 28 Titre : Assessment of inner reliability in the Gauss-Helmert model Type de document : Article/Communication Auteurs : Andreas Ettlinger, Auteur ; Hans Neuner, Auteur Année de publication : 2020 Article en page(s) : pp 13 - 28 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie [Termes descripteurs IGN] coefficient de corrélation [Termes descripteurs IGN] compensation par moindres carrés [Termes descripteurs IGN] détection d'erreur [Termes descripteurs IGN] erreur systématique [Termes descripteurs IGN] fiabilité des données [Termes descripteurs IGN] filtre de Kalman [Termes descripteurs IGN] modèle d'erreur [Termes descripteurs IGN] modèle de Gauss-Helmert [Termes descripteurs IGN] valeur aberrante Résumé : (auteur) In this contribution, the minimum detectable bias (MDB) as well as the statistical tests to identify disturbed observations are introduced for the Gauss-Helmert model. Especially, if the observations are uncorrelated, these quantities will have the same structure as in the Gauss-Markov model, where the redundancy numbers play a key role. All the derivations are based on one-dimensional and additive observation errors respectively offsets which are modeled as additional parameters to be estimated. The formulas to compute these additional parameters with the corresponding variances are also derived in this contribution. The numerical examples of plane fitting and yaw computation show, that the MDB is also in the GHM an appropriate measure to analyze the ability of an implemented least-squares algorithm to detect if outliers are present. Two sources negatively influencing detectability are identified: columns close to the zero vector in the observation matrix B and sub-optimal configuration in the design matrix A. Even if these issues can be excluded, it can be difficult to identify the correct observation as being erroneous. Therefore, the correlation coefficients between two test values are derived and analyzed. Together with the MDB these correlation coefficients are an useful tool to assess the inner reliability – and therefore the detection and identification of outliers – in the Gauss-Helmert model. Numéro de notice : A2020-040 Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1515/jag-2019-0013 date de publication en ligne : 19/10/2019 En ligne : https://doi.org/10.1515/jag-2019-0013 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94511 [article]

Transformation 3D des coordonnées GPS en coordonnées Nord Sahara avec la MRE / Medjahed Sid Ahmed in Géomatique expert, n° 130-131 (octobre-novembre-décembre 2019)

Public [article]  inGéomatique expert > n° 130-131 (octobre-novembre-décembre 2019) . - pp 66 - 71 Titre : Transformation 3D des coordonnées GPS en coordonnées Nord Sahara avec la MRE Type de document : Article/Communication Auteurs : Medjahed Sid Ahmed, Auteur Année de publication : 2019 Article en page(s) : pp 66 - 71 Note générale : bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Géodésie [Termes descripteurs IGN] Algérie [Termes descripteurs IGN] altitude orthométrique [Termes descripteurs IGN] ellipsoïde de Clarke [Termes descripteurs IGN] hauteur ellipsoïdale [Termes descripteurs IGN] Nord Sahara 1959 [Termes descripteurs IGN] régression multiple [Termes descripteurs IGN] système de référence altimétrique [Termes descripteurs IGN] transformation polynomiale [Termes descripteurs IGN] World Geodetic System 1984 Résumé : (éditeur) En Algérie tous les travaux cartographiques sont basés sur le système national NS59 (Nord Sahara 1959)et le référentiel altimétrique NGA (Nivellement général d'Algérie). Pour exploiter localement le GPS, il est essentiel de passer par les transformations entre systèmes de référence. Numéro de notice : A2019-588 Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtSansCL DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94530 [article]

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
IFN-001-P002198	PER	Revue	Nogent-sur-Vernisson	Salle périodiques	Exclu du prêt

A generalized theory of the figure of the Earth : formulae / Chengli Huang in Journal of geodesy, vol 93 n° 3 (March 2019)  

Public [article]  inJournal of geodesy > vol 93 n° 3 (March 2019) . - pp 297 - 317 Titre : A generalized theory of the figure of the Earth : formulae Type de document : Article/Communication Auteurs : Chengli Huang, Auteur ; Yu Liu, Auteur ; Chenjun Liu, Auteur ; Mian Zhang, Auteur Année de publication : 2019 Article en page(s) : pp 297 - 317 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie [Termes descripteurs IGN] croute terrestre [Termes descripteurs IGN] ellipticité (géométrie) [Termes descripteurs IGN] équation de Clairaut [Termes descripteurs IGN] figure de la Terre [Termes descripteurs IGN] surface de référence Résumé : (Auteur) Traditionally a laterally homogeneous and spherical base Earth model (e.g., the PREM model) is considered as input when computing the Earth’s equipotential surfaces, which are then resulted to be in symmetric shape. However, the Earth, known with a complex distribution of interior material and density, especially in the upper mantle and the crust, cannot be treated as a symmetric sphere. Recently, a CRUST1.0 model of crust layer is published and well accepted. But the effect caused by the asymmetric crust (and mantle) on equilibrium figures of the Earth cannot be analyzed by the traditional theories. A generalized theory of the figure of the Earth to third-order precision is firstly proposed in this paper, as well as the iterative calculation strategy to solve the complex equation system. In order to validate this generalized theory, the degeneration of this generalized theory with the PREM model is made and is compared with traditional theories, and it is shown that the result of this generalized theory, after degeneration, is consistent very well with traditional theory. Meanwhile, the effect (including both the direct and indirect effects) of the crust layer, from the CRUST1.0 model, on the figures of equipotential surfaces of the Earth’s interior, as well as their effects on the global dynamics flattening, will be presented as an application of this theory in accompanying paper. Numéro de notice : A2019-150 Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-018-1159-6 date de publication en ligne : 15/06/2018 En ligne : https://doi.org/10.1007/s00190-018-1159-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92488 [article]

A generalized theory of the figure of the Earth : on the global dynamical flattening / Chenjun Liu in Journal of geodesy, vol 93 n° 3 (March 2019)  

Public [article]  inJournal of geodesy > vol 93 n° 3 (March 2019) . - pp 319 - 331 Titre : A generalized theory of the figure of the Earth : on the global dynamical flattening Type de document : Article/Communication Auteurs : Chenjun Liu, Auteur ; Chengli Huang, Auteur ; Yu Liu, Auteur ; Mian Zhang, Auteur Année de publication : 2019 Article en page(s) : pp 319 - 331 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie [Termes descripteurs IGN] aplatissement [Termes descripteurs IGN] croute terrestre [Termes descripteurs IGN] isostasie [Termes descripteurs IGN] manteau terrestre [Termes descripteurs IGN] moment d'inertie [Termes descripteurs IGN] noyau terrestre [Termes descripteurs IGN] rotation de la Terre Résumé : (Auteur) A generalized theory of the figures of the Earth’s interior to a third-order precision of ellipticity is proposed in accompanying paper in which all the odd degree and nonzero order spherical harmonic terms are included. As both the direct and indirect contributions of the asymmetric crust are included, this theory makes a significant improvement for calculating the asymmetric equilibrium figures of the real Earth comparing with the traditional theories which can only deal with the ideal symmetric Earth. The principal moments of inertia (PMOI: A, B, C) and global dynamical flattening (H) are important quantities in studying the rotating Earth. Precession and gravity observations give observation value of H (Hobs≈1/305.4559) with very high precision, while its theoretical calculated value (Htheory≈1/308.5) from traditional theories and a starting symmetric Earth model (like PREM model) is about 1% less than Hobs. Using the new theory in accompanying paper and replacing the homogeneous outermost crust and oceanic layers in PREM with CRUST1.0 model, we recalculate the equilibrium figures of the Earth’s interior and finally get new values of PMOI and Htheory (≈1/304.7167) whose consistency with Hobs are significantly improved to 0.24%. Furthermore, the asymmetric figures of some interesting boundaries, like inner core boundary, core-mantle boundary, are also given as by-products of this work as these boundaries’ figures are key input for studies of their topographic effect on global rotation and geodynamics, like nutation, normal modes, especially like free core nutation. Numéro de notice : A2019-151 Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-018-1163-x date de publication en ligne : 22/06/2018 En ligne : https://doi.org/10.1007/s00190-018-1163-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92490 [article]

Geodesic equations and their numerical solution in Cartesian coordinates on a triaxial ellipsoid / Georgios Panou in Journal of geodetic science, vol 9 n° 1 (January 2019)  

Public [article]  inJournal of geodetic science > vol 9 n° 1 (January 2019) . - pp 1 - 12 Titre : Geodesic equations and their numerical solution in Cartesian coordinates on a triaxial ellipsoid Type de document : Article/Communication Auteurs : Georgios Panou, Auteur ; Romylos Korakitis, Auteur Année de publication : 2019 Article en page(s) : pp 1 - 12 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie [Termes descripteurs IGN] constante [Termes descripteurs IGN] coordonnées cartésiennes géocentriques [Termes descripteurs IGN] coordonnées ellipsoïdales [Termes descripteurs IGN] problème des valeurs limites [Termes descripteurs IGN] transformation de coordonnées Résumé : (auteur) In this work, the geodesic equations and their numerical solution in Cartesian coordinates on an oblate spheroid, presented by Panou and Korakitis (2017), are generalized on a triaxial ellipsoid. A new exact analytical method and a new numerical method of converting Cartesian to ellipsoidal coordinates of a point on a triaxial ellipsoid are presented. An extensive test set for the coordinate conversion is used, in order to evaluate the performance of the two methods. The direct geodesic problem on a triaxial ellipsoid is described as an initial value problem and is solved numerically in Cartesian coordinates. The solution provides the Cartesian coordinates and the angle between the line of constant λ and the geodesic, at any point along the geodesic. Also, the Liouville constant is computed at any point along the geodesic, allowing to check the precision of the method. An extensive data set of geodesics is used, in order to demonstrate the validity of the numerical method for the geodesic problem. We conclude that a complete, stable and precise solution of the problem is accomplished. Numéro de notice : A2019-407 Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jogs-2019-0001 En ligne : https://doi.org/10.1515/jogs-2019-0001 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93524 [article]

A factor model approach for the joint segmentation with between-series correlation / Xavier Collilieux (17/07/2018)  

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Voronoi tessellation on the ellipsoidal earth for vector data / Christos Kastrisios in International journal of geographical information science IJGIS, vol 32 n° 7-8 (July - August 2018)  

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Transformation between surface spherical harmonic expansion of arbitrary high degree and order and double Fourier series on sphere / Toshio Fukushima in Journal of geodesy, vol 92 n° 2 (February 2018)  

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Semi-parametric segmentation of multiple series using a DP-Lasso strategy / Karine Bertin in Journal of Statistical Computation and Simulation, vol 87 n° 6 (2017)  

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Les références de temps et d'espace / Claude Boucher (2017)

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A mixed weighted least squares and weighted total least squares adjustment method and its geodetic applications / Y. Zhou in Survey review, vol 48 n° 351 (October 2016)  

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Eléments de géodésie et de la théorie des moindres carrés / Abdelmajid Ben Hadj Salem (février 2016) 

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IAG history, the years of World Wars and aftermath (1917-1959) / Claude Boucher (2016)  

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Theoretical geodesy / Andrzej Borkowski in Geodesy and cartography, vol 64 n° 2 (December 2015)  

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Updated best practice for EDM calibrations in New South Wales / Volker Janssen in Position, n° 78 (August - September 2015)

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