Geophysical journal international / Royal astronomical society . vol 184 n° 1Paru le : 01/01/2011 |
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Ajouter le résultat dans votre panierWavelet modelling of the gravity field by domain decomposition methods: an example over Japan / Isabelle Panet in Geophysical journal international, vol 184 n° 1 (January 2011)
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Titre : Wavelet modelling of the gravity field by domain decomposition methods: an example over Japan Type de document : Article/Communication Auteurs : Isabelle Panet , Auteur ; Yuki Kuroishi, Auteur ; Matthias Holschneider, Auteur Année de publication : 2011 Article en page(s) : pp 203 - 219 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse harmonique
[Termes IGN] bruit blanc
[Termes IGN] bruit rose
[Termes IGN] harmonique sphérique
[Termes IGN] itération
[Termes IGN] Japon
[Termes IGN] modèle de géopotentiel local
[Termes IGN] potentiel de pesanteur terrestre
[Termes IGN] transformation en ondelettesRésumé : (auteur) With the advent of satellite gravity, large gravity data sets of unprecedented quality at low and medium resolution become available. For local, high resolution field modelling, they need to be combined with the surface gravity data. Such models are then used for various applications, from the study of the Earth interior to the determination of oceanic currents. Here we show how to realize such a combination in a flexible way using spherical wavelets and applying a domain decomposition approach. This iterative method, based on the Schwarz algorithms, allows to split a large problem into smaller ones, and avoids the calculation of the entire normal system, which may be huge if high resolution is sought over wide areas. A subdomain is defined as the harmonic space spanned by a subset of the wavelet family. Based on the localization properties of the wavelets in space and frequency, we define hierarchical subdomains of wavelets at different scales. On each scale, blocks of subdomains are defined by using a tailored spatial splitting of the area. The data weighting and regularization are iteratively adjusted for the subdomains, which allows to handle heterogeneity in the data quality or the gravity variations. Different levels of approximations of the subdomains normals are also introduced, corresponding to building local averages of the data at different resolution levels. We first provide the theoretical background on domain decomposition methods. Then, we validate the method with synthetic data, considering two kinds of noise: white noise and coloured noise. We then apply the method to data over Japan, where we combine a satellite-based geopotential model, EIGEN-GL04S, and a local gravity model from a combination of land and marine gravity data and an altimetry-derived marine gravity model. A hybrid spherical harmonics/wavelet model of the geoid is obtained at about 15 km resolution and a corrector grid for the surface model is derived. Numéro de notice : A2011-604 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1365-246X.2010.04840.x Date de publication en ligne : 01/01/2011 En ligne : https://doi.org/10.1111/j.1365-246X.2010.04840.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91678
in Geophysical journal international > vol 184 n° 1 (January 2011) . - pp 203 - 219[article]Documents numériques
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