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Validating geoid models with marine GNSS measurements, sea surface models, and additional gravity observations in the Gulf of Finland / Timo Saari in Marine geodesy, vol 44 n° 3 (May 2021)
[article]
Titre : Validating geoid models with marine GNSS measurements, sea surface models, and additional gravity observations in the Gulf of Finland Type de document : Article/Communication Auteurs : Timo Saari, Auteur ; Mirjam Bilker-Koivula, Auteur ; Hannu Koivula, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 196 - 214 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] Finlande
[Termes IGN] géodésie marine
[Termes IGN] geoïde marin
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] mesurage par GNSS
[Termes IGN] modèle de géopotentiel
[Termes IGN] nivellement
[Termes IGN] surface de la merRésumé : (auteur) Traditionally, geoid models have been validated using GNSS-levelling benchmarks on land only. As such benchmarks cannot be established offshore, marine areas of geoid models must be evaluated in a different way. In this research, we present a marine GNSS/gravity campaign where existing geoid models were validated at sea areas by GNSS measurements in combination with sea surface models. Additionally, a new geoid model, calculated using the newly collected marine gravity data, was validated. The campaign was carried out with the marine geology research catamaran Geomari (operated by the Geological Survey of Finland), which sailed back and forth the eastern part of the Finnish territorial waters of the Gulf of Finland during the early summer of 2018. From the GNSS and sea surface data we were able to obtain geoid heights at sea areas with an accuracy of a few centimetres. When the GNSS derived geoid heights are compared with geoid heights from the geoid models differences between the respective models are seen in the most eastern and southern parts of the campaign area. The new gravity data changed the geoid model heights by up to 15 cm in areas of sparse/non-existing gravity data. Numéro de notice : A2021-387 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/01490419.2021.1889727 Date de publication en ligne : 11/03/2021 En ligne : https://doi.org/10.1080/01490419.2021.1889727 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97670
in Marine geodesy > vol 44 n° 3 (May 2021) . - pp 196 - 214[article]Strategy for the realisation of the International Height Reference System (IHRS) / Laura Sánchez in Journal of geodesy, vol 95 n° 4 (April 2021)
[article]
Titre : Strategy for the realisation of the International Height Reference System (IHRS) Type de document : Article/Communication Auteurs : Laura Sánchez, Auteur ; Jonas Ågren, Auteur ; Jianliang Huang, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 33 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] Association internationale de géodésie
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] coordonnées géodésiques
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] modèle de géopotentiel
[Termes IGN] norme
[Termes IGN] potentiel de pesanteur terrestre
[Termes IGN] système de référence altimétrique
[Termes IGN] système international de référence altimétriqueRésumé : (auteur) In 2015, the International Association of Geodesy defined the International Height Reference System (IHRS) as the conventional gravity field-related global height system. The IHRS is a geopotential reference system co-rotating with the Earth. Coordinates of points or objects close to or on the Earth’s surface are given by geopotential numbers C(P) referring to an equipotential surface defined by the conventional value W0 = 62,636,853.4 m2 s−2, and geocentric Cartesian coordinates X referring to the International Terrestrial Reference System (ITRS). Current efforts concentrate on an accurate, consistent, and well-defined realisation of the IHRS to provide an international standard for the precise determination of physical coordinates worldwide. Accordingly, this study focuses on the strategy for the realisation of the IHRS; i.e. the establishment of the International Height Reference Frame (IHRF). Four main aspects are considered: (1) methods for the determination of IHRF physical coordinates; (2) standards and conventions needed to ensure consistency between the definition and the realisation of the reference system; (3) criteria for the IHRF reference network design and station selection; and (4) operational infrastructure to guarantee a reliable and long-term sustainability of the IHRF. A highlight of this work is the evaluation of different approaches for the determination and accuracy assessment of IHRF coordinates based on the existing resources, namely (1) global gravity models of high resolution, (2) precise regional gravity field modelling, and (3) vertical datum unification of the local height systems into the IHRF. After a detailed discussion of the advantages, current limitations, and possibilities of improvement in the coordinate determination using these options, we define a strategy for the establishment of the IHRF including data requirements, a set of minimum standards/conventions for the determination of potential coordinates, a first IHRF reference network configuration, and a proposal to create a component of the International Gravity Field Service (IGFS) dedicated to the maintenance and servicing of the IHRS/IHRF. Numéro de notice : A2021-260 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-021-01481-0 Date de publication en ligne : 22/02/2021 En ligne : https://doi.org/10.1007/s00190-021-01481-0 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97300
in Journal of geodesy > vol 95 n° 4 (April 2021) . - n° 33[article]What have we learnt from Icesat on Greenland ice sheet change and what to expect from Icesat 2 / Blaženka Bukač in Geodetski vestnik, vol 65 n° 1 (March - May 2021)
[article]
Titre : What have we learnt from Icesat on Greenland ice sheet change and what to expect from Icesat 2 Type de document : Article/Communication Auteurs : Blaženka Bukač, Auteur ; Marijan Grgić, Auteur ; Tomislav Basic, Auteur Année de publication : 2021 Article en page(s) : pp 94 - 109 Note générale : bibliographie Langues : Anglais (eng) Slovène (slv) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] altimétrie satellitaire par laser
[Termes IGN] bilan de masse
[Termes IGN] calotte glaciaire
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] données GRACE
[Termes IGN] données ICEsat
[Termes IGN] glace de mer
[Termes IGN] glacier
[Termes IGN] Groenland
[Termes IGN] levé gravimétriqueRésumé : (auteur) Ice-sheet mass balance and ice behaviour have been effectively monitored remotely by space-borne laser ranging technology, i.e. satellite laser altimetry, and/or satellite gravimetry. ICESat mission launched in 2003 has pioneered laser altimetry providing a large amount of elevation data related to ice sheet change with high spatial and temporal resolution. ICESat-2, the successor to the ICESat mission, was launched in 2018, continuing the legacy of its predecessor. This paper presents an overview of the satellite laser altimetry and a review of Greenland ice sheet change estimated from ICESat data and compared against estimates derived from satellite gravimetry, i.e. changes of the Earth’s gravity field obtained from the GRACE data.I n addition to that, it provides an insight into the characteristics and possibilities of ice sheet monitoring with renewed mission ICESat-2, which was compared against ICESat for the examination of ice height changes on the Jakobshavn glacier. ICESat comparison (2004–2008) shows that an average elevation change in different areas on Greenland varies up to ±0.60 m yr−1. Island’s coastal southern regions are most affected by ice loss, while inland areas record near-balance state. In the same period, gravity anomaly measurements showed negative annual mass balance trends in coastal regions ranging from a few cm up to-0.36 m yr-1 w.e.(water equivalent), while inlandrecords show slightly positive trends. According to GRACE observations, in the following years (2009–2017), negative annual mass balance trends on the coast continued. Numéro de notice : A2021-313 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.15292/geodetski-vestnik.2021.01.94-109 Date de publication en ligne : 15/01/2021 En ligne : https://doi.org/10.15292/geodetski-vestnik.2021.01.94-109 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97516
in Geodetski vestnik > vol 65 n° 1 (March - May 2021) . - pp 94 - 109[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 139-2021011 RAB Revue Centre de documentation En réserve L003 Disponible
Titre : Geodetic sciences : theory, applications and recent developments Type de document : Monographie Auteurs : Bihter Erol, Éditeur scientifique ; Serdar Erol, Éditeur scientifique Editeur : London [UK] : IntechOpen Année de publication : 2021 Importance : 200 p. Format : 16 x 24 cm ISBN/ISSN/EAN : 978-1-83962-768-2 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] altimétrie par radar
[Termes IGN] analyse comparative
[Termes IGN] champ de gravitation
[Termes IGN] données GNSS
[Termes IGN] données GRACE
[Termes IGN] force de gravitation
[Termes IGN] géodynamique
[Termes IGN] marégraphe
[Termes IGN] niveau de la mer
[Termes IGN] observation de la Terre
[Termes IGN] tectonique des plaquesRésumé : (Editeur) Advances in space-borne technologies lead to improvements in observations and have a notable impact on geodesy and its applications. As a consequence of these improvements in data accuracies, spatial and temporal resolutions, as well as the developments in the methodologies, more detailed analyses of the Earth and a deeper understanding of its state and dynamic processes are possible today. From this perspective, this book is a collection of the selected reviews and case-study articles that report the advances in methodology and applications in geodesy. The chapters in the book are mainly dedicated to the Earth’s gravity field theory and applications, sea level monitoring and analysis, navigation satellite systems data and applications, and monitoring networks for tectonic deformations. This collection is a current state analysis of the geodetic research in theory and applications in today’s modern world. Note de contenu :
1. The Earth’s Gravity Field Role in Geodesy and Large-Scale Geophysics
2. On Moho Determination by the Vening Meinesz-Moritz Technique
3. The Gravity Effect of Topography: A Comparison among Three Different Methods
4. Continental Water Storage Changes Sensed by GRACE Satellite Gravimetry
5. Radar Satellite Altimetry in Geodesy - Theory, Applications and Recent Developments
6. Coastal Sea Level Trends from a Joint Use of Satellite Radar Altimetry, GPS and Tide Gauges: Case Study of the Northern Adriatic Sea
7. Beyond Mapping Functions and Gradients
8. GNSS Networks for Geodynamics in the Caribbean, Northwestern South America, and Central AmericaNuméro de notice : 26670 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Recueil / ouvrage collectif DOI : 10.5772/intechopen.87679 Date de publication en ligne : 30/06/2021 En ligne : https://doi.org/10.5772/intechopen.87679 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98927 Height system unification and estimation of the lithospheric structure beneath Vietnam through high-resolution gravity field and quasigeoid modeling / Dinh Toan Vu (2021)
Titre : Height system unification and estimation of the lithospheric structure beneath Vietnam through high-resolution gravity field and quasigeoid modeling Titre original : Unification du système de hauteur et estimation de la structure lithosphérique sous le Vietnam utilisant la modélisation du champ de gravité et du quasigéoïde à haute résolution Type de document : Thèse/HDR Auteurs : Dinh Toan Vu, Auteur ; Sylvain Bonvalot, Directeur de thèse ; Sean L. Bruinsma, Directeur de thèse Editeur : Toulouse : Université de Toulouse Année de publication : 2021 Importance : 234 p. Format : 21 x 30 cm Note générale : bibliographie
Thèse en vue de l'obtention du Doctorat de l'Université de Toulouse délivrée par l'Université Toulouse 3 - Paul SabatierLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] anomalie de pesanteur
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] données GNSS
[Termes IGN] données GOCE
[Termes IGN] géoïde gravimétrique
[Termes IGN] géoïde local
[Termes IGN] lithosphère
[Termes IGN] modèle de géopotentiel local
[Termes IGN] nivellement
[Termes IGN] quasi-géoïde
[Termes IGN] Viet NamIndex. décimale : THESE Thèses et HDR Résumé : (auteur) The goal of this work was twofold. The first part was devoted to the research of the size and physical shape of the Earth in Vietnam through the determination of a local gravimetric quasigeoid model. The second part was to better constrain the Earth's interior structure beneath Vietnam by determining the Moho and Lithosphere-Asthenosphere Boundary (LAB) depth models. For the first objective, a high-resolution gravimetric quasigeoid model for Vietnam and its surrounding areas was determined based on new land gravity data in combination with fill-in data where no gravity data existed. The resulting quasigeoid model was evaluated using 812 GNSS/levelling points in the study region. This comparison indicates that the quasigeoid model has a standard deviation of 9.7 cm and 50 cm in mean bias. This new local quasigeoid model for Vietnam represents a significant improvement over the global models EIGEN-6C4 and EGM2008, which have standard deviations of 19.2 and 29.1 cm, respectively, when compared to the GNSS/levelling data. An essential societal and engineering application of the gravimetric quasigeoid is in GNSS levelling, and a vertical offset model for Vietnam and its surrounding areas was determined based on the GNSS/levelling points and gravimetric-only quasigeoid model for this purpose. The offset model was evaluated using cross-validation technique by comparing with GNSS/levelling data. Results indicate that the offset model has a standard deviation of 5.9 cm in the absolute sense. Thanks to this offset model, GNSS levelling can be carried out over most of Vietnam's territory complying to third-order levelling requirements, while the accuracy requirements for fourth-order levelling networks is met for the entire country. To unify the height system towards the International Height Reference Frame (IHRF), the zero-height geopotential value for the Vietnam Local Vertical Datum W_0^LVD was determined based on two approaches: 1) Using high-quality GNSS/levelling data and the estimated gravimetric quasigeoid model, 2) Using the Geodetic Boundary Value Problem (GBVP) approach based on the GOCE global gravity field model enhanced with terrestrial gravity data. This geopotential value can be used to connect the height system of Vietnam with the neighboring countries. Moreover, the GBVP approach was also used for direct determination of the gravity potential on the surface at three GNSS Continuously Operating Reference Station (CORS) stations at epoch 2018.0 in Vietnam. Based on time series of the vertical component derived from these GNSS observations as well as InSAR data, temporal variations in the geopotential were also estimated on these permanent GNSS stations. This enables monitoring of the vertical datum and detect possible deformation. These stations may thus contribute to increase the density of reference points in the IHRF for this region. For the second objective, the local quasigeoid model was first converted to the geoid. Then, high-resolution Moho and LAB depth models were determined beneath Vietnam based on the local isostatic hypothesis using the geoid height derived from the estimated geoid, elevation data and thermal analysis. From new land gravity data, a complete grid and map of gravity anomalies i.e., Free-air, Bouguer and Isostatic was determined for the whole of Vietnam. The Moho depth was also computed based on the gravity inversion using the Bouguer gravity anomaly grid. All new models are computed at 1' resolution. The resulting Moho and LAB depth models were evaluated using available seismic data as well as global and local lithospheric models available in the study region. [...] Note de contenu : 1- Introduction
2- Theoretical basis
3- Data and map of gravity anomalies
4- The gravimetric quasigeoid solution
5- Quasigeoïd application for GNSS levelling and height system unification
6- Quasigeoid application for determination of the lithospheric structure
7- Conclusion and perspectivesNuméro de notice : 28495 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse française Note de thèse : Thèse de Doctorat : Sciences de la Terre et des Planètes Solides : Toulouse : 2021 Organisme de stage : Geosciences Environnement Toulouse GET DOI : sans En ligne : http://www.theses.fr/2021TOU30050 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99240 A hybrid approach for recovering high-resolution temporal gravity fields from satellite laser ranging / Anno Löcher in Journal of geodesy, vol 95 n° 1 (January 2021)PermalinkPermalinkThe influence of sea-level changes on geodetic datums along the east coast of China / Yang Liu in Marine geodesy, vol 44 n° 1 (January 2021)PermalinkPossibility to determine highly precise geoid for Egypt territory / Moamen Awad Habib Gad in Geodetski vestnik, vol 64 n° 4 (December 2020 - February 2021)PermalinkOptimizing local geoid undulation model using GPS/levelling measurements and heuristic regression approaches / Mosbeh R. Kaloop in Survey review, vol 52 n° 375 (November 2020)PermalinkFrom space to lithosphere: inversion of the GOCE gravity gradients. Supply to the Earth’s interior study / Matthieu Plasman in Geophysical journal international, vol 223 n° 1 (October 2020)PermalinkSpheroidal spline interpolation and its application in geodesy / Mostafa Kiani in Geodesy and cartography, vol 46 n° 3 (October 2020)PermalinkGRACE-FO precise orbit determination and gravity recovery / Z. Kang in Journal of geodesy, vol 94 n° 9 (September 2020)PermalinkUsing quantum optical sensors for determining the Earth’s gravity field from space / Jurgen Müller in Journal of geodesy, vol 94 n° 8 (August 2020)PermalinkA line integral approach for the computation of the potential harmonic coefficients of a constant density polyhedron / Olivier Jamet in Journal of geodesy, Vol 94 n°3 (March 2020)Permalink