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Continental mass change from GRACE over 2002–2011 and its impact on sea level / O. Baur in Journal of geodesy, vol 87 n° 2 (February 2013)  

Public [article]  inJournal of geodesy > vol 87 n° 2 (February 2013) . - pp 117 - 125 Titre : Continental mass change from GRACE over 2002–2011 and its impact on sea level Type de document : Article/Communication Auteurs : O. Baur, Auteur ; M. Kuhn, Auteur ; Will E. Featherstone, Auteur Année de publication : 2013 Article en page(s) : pp 117 - 125 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] analyse diachronique [Termes IGN] continent [Termes IGN] données GRACE [Termes IGN] eau de fonte [Termes IGN] géocentre [Termes IGN] levé gravimétrique [Termes IGN] masse de la Terre [Termes IGN] niveau de la mer [Termes IGN] niveau moyen des mers [Termes IGN] variation Résumé : (Auteur) Present-day continental mass variation as observed by space gravimetry reveals secular mass decline and accumulation. Whereas the former contributes to sea-level rise, the latter results in sea-level fall. As such, consideration of mass accumulation (rather than focussing solely on mass loss) is important for reliable overall estimates of sea-level change. Using data from the Gravity Recovery And Climate Experiment satellite mission, we quantify mass-change trends in 19 continental areas that exhibit a dominant signal. The integrated mass change within these regions is representative of the variation over the whole land areas. During the integer 9-year period of May 2002 to April 2011, GIA-adjusted mass gain and mass loss in these areas contributed, on average, to -(0.7 + 0.4) mm/year of sea-level fall and + (1.8 + 0.2) mm/year of sea-level rise; the net effect was + (1.1 + 0.6) mm/year. Ice melting over Greenland, Iceland, Svalbard, the Canadian Arctic archipelago, Antarctica, Alaska and Patagonia was responsible for + (1.4+0.2) mm/year of the total balance. Hence, land-water mass accumulation compensated about 20 % of the impact of ice-melt water influx to the oceans. In order to assess the impact of geocentre motion, we converted geocentre coordinates derived from satellite laser ranging (SLR) to degree-one geopotential coefficients. We found geocentre motion to introduce small biases to mass-change and sea-level change estimates; its overall effect is + (0.1 + 0.1) mm/year. This value, however, should be taken with care owing to questionable reliability of secular trends in SLR-derived geocentre coordinates. Numéro de notice : A2013-098 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-012-0583-2 Date de publication en ligne : 14/07/2012 En ligne : https://doi.org/10.1007/s00190-012-0583-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32236 [article]

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Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-2013021	SL	Revue	Centre de documentation	Revues en salle	Disponible

The effect of EGM2008-based normal, normal-orthometric and Helmert orthometric height systems on the Australian levelling network / M. Filmer in Journal of geodesy, vol 84 n° 8 (August 2010)  

Public [article]  inJournal of geodesy > vol 84 n° 8 (August 2010) . - pp 501 - 513 Titre : The effect of EGM2008-based normal, normal-orthometric and Helmert orthometric height systems on the Australian levelling network Type de document : Article/Communication Auteurs : M. Filmer, Auteur ; Will E. Featherstone, Auteur ; M. Kuhn, Auteur Année de publication : 2010 Article en page(s) : pp 501 - 513 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] altitude [Termes IGN] altitude orthométrique [Termes IGN] Australian Height Datum [Termes IGN] Australie [Termes IGN] correction orthométrique [Termes IGN] Earth Gravity Model 2008 [Termes IGN] réseau altimétrique national [Termes IGN] système de référence altimétrique Résumé : (Auteur) This paper investigates the normal-orthometric correction used in the definition of the Australian Height Datum, and also computes and evaluates normal and Helmert orthometric corrections for the Australian National Levelling Network (ANLN). Testing these corrections in Australia is important to establish which height system is most appropriate for any new Australian vertical datum. An approximate approach to assigning gravity values to ANLN benchmarks (BMs) is used, where the EGM2008-modelled gravity field is used to ‘re-construct’ observed gravity at the BMs. Network loop closures (for first- and second-order levelling) indicate reduced misclosures for all height corrections considered, particularly in the mountainous regions of south eastern Australia. Differences between Helmert orthometric and normal-orthometric heights reach 44 cm in the Australian Alps, and differences between Helmert orthometric and normal heights are about 26 cm in the same region. Normal-orthometric heights differ from normal heights by up to 18 cm in mountainous regions >2,000 m. This indicates that the quasigeoid is not compatible with normal-orthometric heights in Australia. Numéro de notice : A2010-441 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-010-0388-0 Date de publication en ligne : 11/06/2010 En ligne : https://doi.org/10.1007/s00190-010-0388-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30634 [article]

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Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-2010081	SL	Revue	Centre de documentation	Revues en salle	Disponible

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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266-06032	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Geoidbestimmung unter Verwendung verschiedener Dichtehypothesen / M. Kuhn (2000)

Public Titre : Geoidbestimmung unter Verwendung verschiedener Dichtehypothesen Titre original : [Estimation de géoïde en utilisant différentes hypothèses de densité] Type de document : Thèse/HDR Auteurs : M. Kuhn, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 2000 Collection : DGK - C Sous-collection : Dissertationen num. 520 Importance : 127 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-9559-5 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] géoïde Index. décimale : 30.41 Géoïde Numéro de notice : 69610 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=62243

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69610-02	30.41	Livre	Centre de documentation	Géodésie	Disponible
69610-01	30.41	Livre	Centre de documentation	Géodésie	Disponible