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A synthetic Earth gravity model designed specially for testing regional gravimetric geoid determination algorithms / I. Baran in Journal of geodesy, vol 80 n° 1 (April 2006)  

Public [article]  inJournal of geodesy > vol 80 n° 1 (April 2006) . - pp 1 - 16 Titre : A synthetic Earth gravity model designed specially for testing regional gravimetric geoid determination algorithms Type de document : Article/Communication Auteurs : I. Baran, Auteur ; M. Kuhn, Auteur ; S.J. Claessens, Auteur ; et al., Auteur Année de publication : 2006 Article en page(s) : pp 1 - 16 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] Australian Height Datum [Termes IGN] Australie [Termes IGN] champ de pesanteur terrestre [Termes IGN] géoïde gravimétrique [Termes IGN] géoïde local [Termes IGN] géoïde terrestre [Termes IGN] modèle numérique de surface [Termes IGN] nivellement Résumé : (Auteur) A synthetic [simulated] Earth gravity model (SEGM) of the geoid, gravity and topography has been constructed over Australia specifically for validating regional gravimetric geoid determination theories, techniques and computer software. This regional high-resolution (1-arc-min by 1-arc-min) Australian SEGM (AusSEGM) is a combined source and effect model. The long-wavelength effect part (up to and including spherical harmonic degree and order 360) is taken from an assumed errorless EGM96 global geopotential model. Using forward modelling via numerical Newtonian integration, the short-wavelength source part is computed from a high-resolution (3-arc-sec by 3-arc-sec) synthetic digital elevation model (SDEM), which is a fractal surface based on the GLOBE v1 DEM. All topographic masses are modelled with a constant mass-density of 2,670 kg/m3. Based on these input data, gravity values on the synthetic topography (on a grid and at arbitrarily distributed discrete points) and consistent geoidal heights at regular 1-arc-min geographical grid nodes have been computed. The precision of the synthetic gravity and geoid data (after a first iteration) is estimated to be better than 30 u Gal and 3 mm, respectively, which reduces to 1 u Gal and 1 mm after a second iteration. The second iteration accounts for the changes in the geoid due to the superposed synthetic topographic mass distribution. The first iteration of AusSEGM is compared with Australian gravity and GPS-levelling data to verify that it gives a realistic representation of the Earth's gravity field. As a by-product of this comparison, AusSEGM gives further evidence of the north-south-trending error in the Australian Height Datum. The freely available AusSEGM-derived gravity and SDEM data, included as Electronic Supplementary Material (ESM) with this paper, can be used to compute a geoid model that, if correct, will agree to in 3 mm with the AusSEGM geoidal heights, thus offering independent verification of theories and numerical techniques used for regional geoid modelling Numéro de notice : A2006-177 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-005-0002-z En ligne : https://doi.org/10.1007/s00190-005-0002-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27904 [article]

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