Descripteur
Termes IGN > sciences naturelles > sciences de la Terre et de l'univers > géosciences > géophysique interne > géodésie > géodésie physique > pesanteur terrestre > anomalie de pesanteur
anomalie de pesanteurVoir aussi |
Documents disponibles dans cette catégorie (169)
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
Mean dynamic topography and geostrophic surface currents in the Fram Strait derived from geodetic data / D. Lysaker in Marine geodesy, vol 32 n° 1 (January - March 2009)
[article]
Titre : Mean dynamic topography and geostrophic surface currents in the Fram Strait derived from geodetic data Type de document : Article/Communication Auteurs : D. Lysaker, Auteur Année de publication : 2009 Article en page(s) : pp 42 - 63 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] anomalie de pesanteur
[Termes IGN] circulation géostrophique
[Termes IGN] collocation par moindres carrés
[Termes IGN] Groenland
[Termes IGN] océanographie dynamique
[Termes IGN] surface de la mer
[Termes IGN] SvalbardRésumé : (Auteur) Two mean dynamic topography (MDT) fields are determined in the Fram Strait between Svalbard and Greenland. New airborne gravity anomalies, older data, and two different mean sea surface (MSS) fields are combined using the least squares collocation (LSC) technique. The results are compared to an oceanographic MDT model and two synthetic MDT fields. The same main currents are seen in all fields. Additionally, smaller scale features are revealed in the new MDT fields. Geostrophic surface currents derived from the MDT models are compared to moorings and Lagrangian drifters. The agreement is desultory. The oceanographic data are an inadequate basis of comparison due to data gaps. Nevertheless, it is the only one available. Copyright Taylor & Francis Numéro de notice : A2009-190 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/01490410802662029 En ligne : https://doi.org/10.1080/01490410802662029 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29820
in Marine geodesy > vol 32 n° 1 (January - March 2009) . - pp 42 - 63[article]Réservation
Réserver ce documentExemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité 230-09011 RAB Revue Centre de documentation En réserve L003 Disponible A data-driven approach to local gravity field modelling using spherical radial basis functions / R. Klees in Journal of geodesy, vol 82 n° 8 (August 2008)
[article]
Titre : A data-driven approach to local gravity field modelling using spherical radial basis functions Type de document : Article/Communication Auteurs : R. Klees, Auteur ; Robert Tenzer, Auteur ; I. Prutkin, Auteur ; Tobias Wittwer, Auteur Année de publication : 2008 Article en page(s) : pp 457 - 471 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] anomalie de pesanteur
[Termes IGN] champ de pesanteur local
[Termes IGN] fonction de base radiale
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] nivellement par GPS
[Termes IGN] Pays-Bas
[Termes IGN] problème des valeurs limitesRésumé : (Auteur) We propose a methodology for local gravity field modelling from gravity data using spherical radial basis functions. The methodology comprises two steps: in step 1, gravity data (gravity anomalies and/or gravity disturbances) are used to estimate the disturbing potential using least-squares techniques. The latter is represented as a linear combination of spherical radial basis functions (SRBFs). A data-adaptive strategy is used to select the optimal number, location, and depths of the SRBFs using generalized cross validation. Variance component estimation is used to determine the optimal regularization parameter and to properly weight the different data sets. In the second step, the gravimetric height anomalies are combined with observed differences between global positioning system (GPS) ellipsoidal heights and normal heights. The data combination is written as the solution of a Cauchy boundary-value problem for the Laplace equation. This allows removal of the non-uniqueness of the problem of local gravity field modelling from terrestrial gravity data. At the same time, existing systematic distortions in the gravimetric and geometric height anomalies are also absorbed into the combination. The approach is used to compute a height reference surface for the Netherlands. The solution is compared with NLGEO2004, the official Dutch height reference surface, which has been computed using the same data but a Stokes-based approach with kernel modification and a geometric six-parameter “corrector surface” to fit the gravimetric solution to the GPS-levelling points. A direct comparison of both height reference surfaces shows an RMS difference of 0.6 cm; the maximum difference is 2.1 cm. A test at independent GPS-levelling control points, confirms that our solution is in no way inferior to NLGEO2004. Copyright Springer Numéro de notice : A2008-319 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-007-0196-3 En ligne : https://doi.org/10.1007/s00190-007-0196-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29312
in Journal of geodesy > vol 82 n° 8 (August 2008) . - pp 457 - 471[article]Réservation
Réserver ce documentExemplaires (2)
Code-barres Cote Support Localisation Section Disponibilité 266-08071 RAB Revue Centre de documentation En réserve L003 Disponible 266-08072 RAB Revue Centre de documentation En réserve L003 Disponible On the non-uniqueness of local quasi-geoids computed from terrestrial gravity anomalies / I. Prutkin in Journal of geodesy, vol 82 n° 3 (March 2008)
[article]
Titre : On the non-uniqueness of local quasi-geoids computed from terrestrial gravity anomalies Type de document : Article/Communication Auteurs : I. Prutkin, Auteur ; R. Klees, Auteur Année de publication : 2008 Article en page(s) : pp 147 - 156 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] anomalie de pesanteur
[Termes IGN] champ de pesanteur local
[Termes IGN] données GPS
[Termes IGN] géoïde local
[Termes IGN] nivellement par GPSRésumé : (Auteur) We consider the problem of local (quasi-)geoid modelling from terrestrial gravity anomalies. Whereas this problem is uniquely solvable (up to spherical harmonic degree one) if gravity anomalies are globally available, the problem is non-unique if gravity anomalies are only available within a local area, which is the typical situation in local/regional gravity field modelling. We derive a mathematical description of the kernel of the gravity anomaly operator. The non-uniqueness can be removed using external height anomaly information, e.g., provided by GPS-levelling. The corresponding problem is formulated as a Cauchy problem for the Laplace equation. The existence and uniqueness of the solution of the Cauchy problem is guaranteed by the Cauchy–Kowalevskaya theorem. We propose several numerical procedures to compute the solution of the Cauchy problem from given differences between gravimetric and geometric height anomalies. We apply the numerical techniques to real data over the Netherlands and Germany. We show that we can compute a unique quasi-geoid from observed gravimetric and geometric height anomalies, which agree with the data within the expected noise level. We conclude that observed differences between gravimetric height anomalies and geometric height anomalies derived from GPS and levelling cannot only be attributed to systematic errors in the data sets, but are also caused by the intrinsic non-uniqueness of the problem of local quasi-geoid modelling from gravity anomalies. Hence, GPS-levelling data are necessary to get a unique solution, which also implies that they should not be used to validate local quasi-geoid solutions computed on the basis of gravity anomalies. Copyright Springer Numéro de notice : A2008-166 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-007-0161-1 En ligne : https://doi.org/10.1007/s00190-007-0161-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29161
in Journal of geodesy > vol 82 n° 3 (March 2008) . - pp 147 - 156[article]Réservation
Réserver ce documentExemplaires (2)
Code-barres Cote Support Localisation Section Disponibilité 266-08031 RAB Revue Centre de documentation En réserve L003 Disponible 266-08032 RAB Revue Centre de documentation En réserve L003 Disponible Generation of study of high-resolution satellite gravity over the Sumatra earthquake region / Samprit Chatterjee in International Journal of Remote Sensing IJRS, vol 28 n° 13-14 (July 2007)
[article]
Titre : Generation of study of high-resolution satellite gravity over the Sumatra earthquake region Type de document : Article/Communication Auteurs : Samprit Chatterjee, Auteur ; R. Bhattacharyya, Auteur ; T.J. Majumdar, Auteur Année de publication : 2007 Article en page(s) : pp 2915 - 2925 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] anomalie de pesanteur
[Termes IGN] carte gravimétrique
[Termes IGN] déformation de la croute terrestre
[Termes IGN] données altimétriques
[Termes IGN] épicentre
[Termes IGN] gravimétrie spatiale
[Termes IGN] prévention des risques
[Termes IGN] risque naturel
[Termes IGN] séisme
[Termes IGN] Sumatra
[Termes IGN] tectonique des plaquesRésumé : (Auteur) We have utilized satellite altimetry data to generate the very high-resolution gravity anomaly maps to infer subsurface geological structures in the area of the devastating earthquake (and the corresponding tsunami) that struck the Indian Ocean near Sumatra (Indonesia) on 26 December 2004. In the present study, a high-resolution three-dimensional (3D) gravity image has been generated over a part of the eastern Indian offshore encompassing the Sumatran earthquake region apart from Ninety East Ridge, Andaman subduction zone, etc. Four latitudinal (2°, 3°, 4° and 8.6° N) gravity profiles have been generated across the epicentre (3° N/M w 9.0)/aftershock regions (4° N/M w 5.8 and 8.6° N/M w 6.0 and 6.6). A drastic change of gravity anomaly patterns (sim130 mGal) near the epicentre and the aftershock regions could be observed, which are however slowly diminishing further away from the epicentre. This gravitational difference might have been caused by the differences in plate tectonic processes. Minor/major gravitational differences in other areas may be due to the changes in densities of different lithospheric zones/sedimentary layers. Hence, our study further supports the idea that negative gravity and topography anomalies can be used as a predictor for occurrences of large earthquakes in subduction zones. Copyright Taylor & Francis Numéro de notice : A2007-336 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160601091829 En ligne : https://doi.org/10.1080/01431160601091829 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28699
in International Journal of Remote Sensing IJRS > vol 28 n° 13-14 (July 2007) . - pp 2915 - 2925[article]Réservation
Réserver ce documentExemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité 080-07081 RAB Revue Centre de documentation En réserve L003 Disponible
Titre : Modelling the vertical gravity gradient for gravity measurements reduction 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 381 - 385 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] anomalie de pesanteur
[Termes IGN] France (administrative)
[Termes IGN] gradient de gravitation
[Termes IGN] réseau gravimétrique localRésumé : (auteur) When establishing the gravity network, precise values of the vertical gravity gradient are needed to reduce measurements at the level of benchmarks. As the determination of the gradient is timeconsuming and expensive, this article presents the first effort of modelling it within the scope of the new French gravity network. Some existing mathematical models based upon derivation of geoid undulation or gravity anomalies integration are listed and commented. Variants using terrain information are also tested. Gradients measured and modelled by several methods are compared, leading to a standard deviation of the differences of 14.5×10−8 s−2 (145 E) with the best method. Numéro de notice : C2006-040 Affiliation des auteurs : LAREG (1991-2011) Thématique : POSITIONNEMENT Nature : Communication DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102797 Documents numériques
peut être téléchargé
Modelling the vertical gravity gradient ... - pdf éditeurAdobe Acrobat PDF The ellipsoidal correction to the Stokes kernel for precise geoid determination / M. Najafi-Alamdari in Journal of geodesy, vol 80 n° 12 (December 2006)PermalinkChoix optimal d'un modèle analytique de covariance pour la validation des mesures gravimétriques par la méthode de collocation (application : nord de l'Algérie) / S.A. Benahmed Daho in XYZ, n° 108 (septembre - novembre 2006)PermalinkNew insights on intraplate volcanism in French Polynesia from wavelet analysis of GRACE, CHAMP, and sea surface data / Isabelle Panet in Journal of geophysical research : Solid Earth, vol 111 n° B9 (September 2006)PermalinkA strategy for determining the regional geoid by combining limited ground data with satellite-based global geopotential and topographical models: a case study of Iran / R. Kiamehr in Journal of geodesy, vol 79 n° 10-11 (February 2006)PermalinkEffect of the STRM global DEM on the determination of a high-resolution geoid model: A case study in Iran / R. Kiamehr in Journal of geodesy, vol 79 n° 9 (December 2005)PermalinkWavelet filter analysis of local atmospheric pressure effects on gravity variations / X.G. Hu in Journal of geodesy, vol 79 n° 8 (November 2005)PermalinkCalcul d'un modèle de géoïde gravimétrique, évaluation de ses applications au nivellement par GPS et interprétation géophysique de ses ondulations sur le Cameroun / J. Kamguia (2005)PermalinkGravity, geoid and space missions GGSM 2004, IAG international symposium, Porto, Portugal, August 30 - September 3, 2004 / Christopher Jekeli (2005)PermalinkPhysical geodesy / Bernhard Hofmann-Wellenhof (2005)PermalinkAmélioration du champ de pesanteur et du géoïde autour de la Corse par gravimétrie aéroportée / Henri Duquenne in XYZ, n° 101 (décembre 2004 - février 2005)Permalink