Descripteur
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
géoïde
Commentaire :
Terme(s) générique(s) :
géographie mathématique, géophysique, mesure. >> astronomie, gravité, arpentage. >>Terme(s) spécifique(s) : astronomie géodésique, aéronautique en géodésie, astronautique en géodésie, astronomie sphérique, azimut, isostasie, latitude, longitude, position géographique, satellite artificiel en géodésie, triangulation. Equiv. LCSH : Geodesy. Domaine(s) : 520; 550. Voir aussi |
Documents disponibles dans cette catégorie (514)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
Kriging and moving window kriging on a sphere in geometric (GNSS/levelling) geoid modelling / M. Ligas in Survey review, vol 50 n° 359 (March 2018)
[article]
Titre : Kriging and moving window kriging on a sphere in geometric (GNSS/levelling) geoid modelling Type de document : Article/Communication Auteurs : M. Ligas, Auteur ; M. Kulczycki, Auteur Année de publication : 2018 Article en page(s) : pp 155 - 162 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] Earth Gravity Model 2008
[Termes IGN] Etats-Unis
[Termes IGN] géoïde local
[Termes IGN] krigeageRésumé : (auteur) A comparison of kriging and moving window kriging (MWK) on a sphere is performed on GNSS/levelling data. The study was to give the answer on whether there is a significant gain in prediction accuracy when we apply an MWK instead of ‘classical’ kriging and also to what extent the use of global geopotential model EGM2008 improves prediction. The quality of prediction for all kriging and data variants has been investigated on three regions (being on the territory of the conterminous USA) characterised with a different spatial extent and density of sampling. Numerical tests revealed that in case of high-sampling density there was no accuracy gain when using MWK instead of classical kriging (cK). In contrast, for less numerous datasets and a much larger spatial extent (low-sampling density) MWK adapts itself to data much better than cK. Incorporation of EGM2008-based undulations as a long-wavelength trend for both cases (classical and moving window) significantly improved prediction quality. Numéro de notice : A2018-181 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/00396265.2016.1247131 Date de publication en ligne : 09/11/2016 En ligne : https://doi.org/10.1080/00396265.2016.1247131 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89825
in Survey review > vol 50 n° 359 (March 2018) . - pp 155 - 162[article]Regional geoid computation by least squares modified Hotine’s formula with additive corrections / Silja Märdla in Journal of geodesy, vol 92 n° 3 (March 2018)
[article]
Titre : Regional geoid computation by least squares modified Hotine’s formula with additive corrections Type de document : Article/Communication Auteurs : Silja Märdla, Auteur ; Artu Ellmann, Auteur ; Jonas Ågren, Auteur ; Lard Erik Sjöberg, Auteur Année de publication : 2018 Article en page(s) : pp 253 - 270 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] anomalie de pesanteur
[Termes IGN] formule de Stokes
[Termes IGN] géoïde local
[Termes IGN] méthode des moindres carrés
[Termes IGN] quasi-géoïdeRésumé : (Auteur) Geoid and quasigeoid modelling from gravity anomalies by the method of least squares modification of Stokes’s formula with additive corrections is adapted for the usage with gravity disturbances and Hotine’s formula. The biased, unbiased and optimum versions of least squares modification are considered. Equations are presented for the four additive corrections that account for the combined (direct plus indirect) effect of downward continuation (DWC), topographic, atmospheric and ellipsoidal corrections in geoid or quasigeoid modelling. The geoid or quasigeoid modelling scheme by the least squares modified Hotine formula is numerically verified, analysed and compared to the Stokes counterpart in a heterogeneous study area. The resulting geoid models and the additive corrections computed both for use with Stokes’s or Hotine’s formula differ most in high topography areas. Over the study area (reaching almost 2 km in altitude), the approximate geoid models (before the additive corrections) differ by 7 mm on average with a 3 mm standard deviation (SD) and a maximum of 1.3 cm. The additive corrections, out of which only the DWC correction has a numerically significant difference, improve the agreement between respective geoid or quasigeoid models to an average difference of 5 mm with a 1 mm SD and a maximum of 8 mm. Numéro de notice : A2018-060 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1061-7 Date de publication en ligne : 11/09/2017 En ligne : https://doi.org/10.1007/s00190-017-1061-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89393
in Journal of geodesy > vol 92 n° 3 (March 2018) . - pp 253 - 270[article]The first Australian gravimetric quasigeoid model with location-specific uncertainty estimates / Will E. Featherstone in Journal of geodesy, vol 92 n° 2 (February 2018)
[article]
Titre : The first Australian gravimetric quasigeoid model with location-specific uncertainty estimates Type de document : Article/Communication Auteurs : Will E. Featherstone, Auteur ; Jack C. McCubbine, Auteur ; Nicholas J. Brown, Auteur ; S.J. Claessens, Auteur ; M. S. Filmer, Auteur ; J.F. Kirby, Auteur Année de publication : 2018 Article en page(s) : pp 149 - 168 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] Australie
[Termes IGN] géoïde gravimétrique
[Termes IGN] géoïde local
[Termes IGN] propagation d'erreur
[Termes IGN] quasi-géoïdeRésumé : (Auteur) We describe the computation of the first Australian quasigeoid model to include error estimates as a function of location that have been propagated from uncertainties in the EGM2008 global model, land and altimeter-derived gravity anomalies and terrain corrections. The model has been extended to include Australia’s offshore territories and maritime boundaries using newer datasets comprising an additional ∼280,000 land gravity observations, a newer altimeter-derived marine gravity anomaly grid, and terrain corrections at 1′′×1′′ resolution. The error propagation uses a remove–restore approach, where the EGM2008 quasigeoid and gravity anomaly error grids are augmented by errors propagated through a modified Stokes integral from the errors in the altimeter gravity anomalies, land gravity observations and terrain corrections. The gravimetric quasigeoid errors (one sigma) are 50–60 mm across most of the Australian landmass, increasing to ∼100 mm in regions of steep horizontal gravity gradients or the mountains, and are commensurate with external estimates. Numéro de notice : A2018-059 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1053-7 En ligne : https://doi.org/10.1007/s00190-017-1053-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89392
in Journal of geodesy > vol 92 n° 2 (February 2018) . - pp 149 - 168[article]Applying the GOCE-based GGMs for the quasi-geoid modelling of Finland / Timo Saari in Journal of applied geodesy, vol 12 n° 1 (January 2018)
[article]
Titre : Applying the GOCE-based GGMs for the quasi-geoid modelling of Finland Type de document : Article/Communication Auteurs : Timo Saari, Auteur ; Mirjam Bilker-Koivula, Auteur Année de publication : 2018 Article en page(s) : pp - 15 - 28 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] données GOCE
[Termes IGN] Finlande
[Termes IGN] géoïde local
[Termes IGN] levé gravimétrique
[Termes IGN] nivellement par GPS
[Termes IGN] pesanteur terrestre
[Termes IGN] quasi-géoïdeMots-clés libres : GOCE Quasi-geoid GPS-levelling Gravity EIGEN-6C4 NKG2015 Résumé : (auteur) The gravity satellite mission GOCE made its final observations in the fall of 2013. Since the reentry to the Earth’s atmosphere, the full cycle of the GOCE data has been published by ESA. At first, we evaluated all the GOCE-based global geoid models over Finland using terrestrial gravity and GNSS-levelling data. The most suitable model was selected as a global background model for the Finnish quasi-geoid calculations. Next, we combined the chosen model with terrestrial gravity data of Finland and surrounding areas. Quasi-geoid models with different modifications were calculated using the GOCE DIR5 model up to spherical harmonic degree and order (d/o) 240 and 300, and the high resolution EIGEN-6C4 (includes the complete GOCE data) model up to degree and order 1000 and 2190. The calculated quasi-geoid models were validated to the measurements on site with two independent GPS-levelling datasets. The best quasi-geoid models with GOCE gave standard deviations of 2.6 cm (FIN_DIR5 d/o 240) and 2.3 cm (FIN_DIR5 d/o 300) in Finland. For the high resolution model FIN_EIGEN-6C4, the results were 1.8 cm (d/o 1000) and 1.7 cm (d/o 2190). In addition, the results were compared with the latest geoid models available in Finland (FIN2005N00, NKG2004, NKG2015, EGG2008). The sub-2-centimetre (and near 2 cm, when using the GOCE-based models) accuracy is an improvement over the previous and current Finnish geoid models. Numéro de notice : A2018-014 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2017-0020 En ligne : https://doi.org/10.1515/jag-2017-0020 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89093
in Journal of applied geodesy > vol 12 n° 1 (January 2018) . - pp - 15 - 28[article]Assessing the quality of GEOID12B model through field surveys / Ahmed F. Elaksher in Journal of applied geodesy, vol 12 n° 1 (January 2018)
[article]
Titre : Assessing the quality of GEOID12B model through field surveys Type de document : Article/Communication Auteurs : Ahmed F. Elaksher, Auteur ; Franck Kamtchang, Auteur ; Christian Wegmann, Auteur ; Adalberto Guerrero, Auteur Année de publication : 2018 Article en page(s) : pp 1 - 14 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] altitude orthométrique
[Termes IGN] anomalie de pesanteur
[Termes IGN] Etats-Unis
[Termes IGN] géoïde local
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] quasi-géoïdeRésumé : (auteur) Elevation differences have been determined through conventional ground surveying techniques for over a century. Since the mid-80s GPS, GLONASS and other satellite systems have modernized the means by which elevation differences are observed. In this article, we assessed the quality of GEIOD12B through long-occupation GNSS static surveys. A set of NGS benchmarks was occupied for at least one hour using dual-frequency GNSS receivers. Collected measurements were processed using a single CORS station at most 24 kilometers from the benchmarks. Geoid undulation values were driven by subtracting measured ellipsoidal heights from the orthometric heights posted on the NGS website. To assess the quality of GEOID12B, we compared our computed vertical shifts at the benchmarks with those estimated from GEOID12B published by NGS. In addition, Kriging model was used to interpolate local maps for the geoid undulations from the benchmark heights. The maps were compared with corresponding parts of GEOID12B. No biases were detected in the results and only shifts due to random errors were found. Discrepancies in the range of ten centimetres were noticed between our geoid undulation and the values available from NGS. Numéro de notice : A2018-013 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2017-0013 En ligne : https://doi.org/10.1515/jag-2017-0013 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89092
in Journal of applied geodesy > vol 12 n° 1 (January 2018) . - pp 1 - 14[article]Contribution actuelle de la calotte Antarctique à la variation du niveau marin / Clémence Chupin (2018)PermalinkDétermination d’un modèle géopotentiel à haute résolution en zone littorale aidé par des mesures d’horloges atomiques / Hugo Lecomte (2018)PermalinkHeight biases of SRTM DEM related to EGM96: from a global perspective to regional practice / A. Üstün in Survey review, vol 50 n° 358 (January 2018)PermalinkOn the geoid and orthometric height vs. quasigeoid and normal height / Lars E. Sjöberg in Journal of geodetic science, vol 8 n° 1 (January 2018)PermalinkOn the topographic bias and density distribution in modelling the geoid and orthometric heights / Lars E. Sjöberg in Journal of geodetic science, vol 8 n° 1 (January 2018)PermalinkOn the equivalence of spherical splines with least-squares collocation and Stokes’s formula for regional geoid computation / Vegard Ophaug in Journal of geodesy, vol 91 n° 11 (November 2017)PermalinkSpace-wise approach for airborne gravity data modelling / Daniele Sampietro in Journal of geodesy, vol 91 n° 5 (May 2017)PermalinkCalcul du quasi-géoïde QGF16 et de la grille de conversion altimétrique RAF16 : état d'avancement et perspectives / François L'écu in XYZ, n° 150 (mars - mai 2017)PermalinkLe chemin vers un système de référence altimétrique global et unifié / Laura Sánchez in XYZ, n° 150 (mars - mai 2017)PermalinkDétermination pratique de modèles de géoïde et autres surfaces de référence altimétrique / Jean-Louis Carme in XYZ, n° 150 (mars - mai 2017)Permalink