Centre dedocumentation
scientifique

Evaluation of global ocean tide models based on tidal gravity observations in China / Hongbo Tan in Geodesy and Geodynamics, vol 12 n° 6 (November 2021)  

Public [article]  inGeodesy and Geodynamics > vol 12 n° 6 (November 2021) . - pp 451 - 458 Titre : Evaluation of global ocean tide models based on tidal gravity observations in China Type de document : Article/Communication Auteurs : Hongbo Tan, Auteur ; Olivier Francis, Auteur ; Guiju Wu, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 451 - 458 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] Chine [Termes IGN] effet de charge [Termes IGN] marée océanique [Termes IGN] modèle océanographique [Termes IGN] surcharge océanique Résumé : (auteur) Previous studies show that the calculated loading effects from global ocean tide models do not match actual measurements of gravity attraction and loading effects in Southeast Asia. In this paper, taking advantage of a unique network of gravity tidal stations all over the Chinese mainland, we compare the observed and modeled tidal loading effects on the basis of the most recent global ocean tide models. The results show that the average efficiencies of the ocean tidal loading correction for O1, K1, M2 are 77%, 73% and 59%, respectively. The loading correction efficiencies using recent ocean tidal models are better than the 40 years old Schwiderskis model at coastal stations, but relative worse at stations far from ocean. Numéro de notice : A2021-885 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1016/j.geog.2021.08.001 Date de publication en ligne : 13/08/2021 En ligne : https://doi.org/10.1016/j.geog.2021.08.001 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99208 [article]

Metamorphic transformation rate over large spatial and temporal scales constrained by geophysical data and coupled modelling / Gyorgy Hetényl in Journal of metamorphic geology, vol 39 n° 9 (December 2021)  

Public [article]  inJournal of metamorphic geology > vol 39 n° 9 (December 2021) . - pp 1131 - 1143 Titre : Metamorphic transformation rate over large spatial and temporal scales constrained by geophysical data and coupled modelling Type de document : Article/Communication Auteurs : Gyorgy Hetényl, Auteur ; Kristel Chanard , Auteur ; Lukas P. Baumgartner, Auteur ; Frédéric Herman, Auteur Année de publication : 2021 Projets : 3-projet - voir note / Article en page(s) : pp 1131 - 1143 Note générale : bibliographie We are grateful to the Swiss National Science Foundation for funding project OROG3NY through grant PP00P2_157627. Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] anomalie de pesanteur [Termes IGN] croute terrestre [Termes IGN] géodynamique [Termes IGN] Inde [Termes IGN] modèle numérique [Termes IGN] roche métamorphique Résumé : (auteur) Metamorphic transformation rates are classically determined on decimetre-scale field samples and from laboratory experiments at smaller scales. Here we present a geophysical approach based on field data and joint geophysical–petrological modelling to quantify the average rate of metamorphic transformations at the 10–100-kilometre and million-year scales. The model simulates the eclogitization of Indian lower crust as it penetrates beneath southern Tibet. Metamorphic transformation of the lower crust is tracked by its densification, the effect of which is then compared to observed gravity anomalies. From the modelling we find that the Indian lower crust's overall densification requires a partially hydrated initial composition. Moreover, the modelled evolution of this densification compared to what is predicted by pressure–temperature–density grids is consistent with delayed, far-from-equilibrium metamorphism. The Indian lower crust descends underneath the Himalaya until beneath southern Tibet in a thermodynamically metastable state until the first dehydration reactions are reached. This observation is used to determine the average rate of metastable rock transformation to an eclogite facies assemblage, constrained at between ~6 × 10−9 and 5 × 10−7 g/cm2/year, and reaction affinity at 0.8–1.6 kJ/mol oxygen. Compared to field and laboratory data, this range of results matches the effective rates typically associated with regional metamorphism. This fit and correlation across the scales legitimates the use of transformation rates determined at small scales in large-scale geodynamic studies. Numéro de notice : A2021-789 Affiliation des auteurs : UMR IPGP-Géod+Ext (2020- ) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/jmg.12604 En ligne : https://doi.org/10.1111/jmg.12604 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98988 [article]

Baseline-dependent clock offsets in VLBI data analysis / Hana Krásná in Journal of geodesy, vol 95 n° 12 (December 2021)  

Public [article]  inJournal of geodesy > vol 95 n° 12 (December 2021) . - n° 126 Titre : Baseline-dependent clock offsets in VLBI data analysis Type de document : Article/Communication Auteurs : Hana Krásná, Auteur ; Frédéric Jaron, Auteur ; Jacob Gruber, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 126 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux [Termes IGN] bande S [Termes IGN] décalage d'horloge [Termes IGN] données ITGB [Termes IGN] horloge atomique [Termes IGN] interférométrie à très grande base [Termes IGN] ligne de base [Termes IGN] paramètres d'orientation de la Terre [Termes IGN] retard ionosphèrique Résumé : (auteur) The primary goal of the geodetic Very Long Baseline Interferometry (VLBI) technique is to provide highly accurate terrestrial and celestial reference frames as well as Earth orientation parameters. In compliance with the concept of VLBI, additional parameters reflecting relative offsets and variations of the atomic clocks of the radio telescopes have to be estimated. In addition, reality shows that in many cases significant offsets appear in the observed group delays for individual baselines which have to be compensated for by estimating so-called baseline-dependent clock offsets (BCOs). For the first time, we systematically investigate the impact of BCOs to stress their importance for all kinds of VLBI data analyses. For our investigations, we concentrate on analyzing data from both legacy networks of the CONT17 campaign. Various aspects of BCOs including their impact on the estimates of geodetically important parameters, such as station coordinates and Earth orientation parameters, are investigated. In addition, some of the theory behind the BCO determination, e.g., the impact of changing the reference clock in the observing network on the BCO estimate is introduced together with the relationship between BCOs and triangle delay closures. In conclusion, missing channels, and here in particular at S band, affecting the ionospheric delay calibration, are identified to be the dominant cause for the occurrence of significant BCOs in VLBI data analysis. Numéro de notice : A2021-815 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-021-01579-5 Date de publication en ligne : 01/11/2021 En ligne : https://doi.org/10.1007/s00190-021-01579-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98896 [article]

Geoid determination through the combined least-squares adjustment of GNSS/levelling/gravity networks – a case study in Linyi, China / Dongmei Guo in Survey review, Vol 53 n° 381 (November 2021)  

Public [article]  inSurvey review > Vol 53 n° 381 (November 2021) . - pp 504 - 512 Titre : Geoid determination through the combined least-squares adjustment of GNSS/levelling/gravity networks – a case study in Linyi, China Type de document : Article/Communication Auteurs : Dongmei Guo, Auteur ; Zhixin Xue, Auteur Année de publication : 2021 Article en page(s) : pp 504 - 512 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] analyse de variance [Termes IGN] Chine [Termes IGN] compensation par moindres carrés [Termes IGN] données GNSS [Termes IGN] géoïde altimétrique [Termes IGN] géoïde local [Termes IGN] levé gravimétrique [Termes IGN] méthode des moindres carrés [Termes IGN] modèle stochastique [Termes IGN] pondération [Termes IGN] réseau de nivellement [Termes IGN] réseau gravimétrique Résumé : (Auteur) A detailed discussion of the adjustment problems used to combine GNSS/levelling/gravity network data is provided in this paper. The two primary problems inherent to heterogeneous data networks, namely, parametric models that describe the datums and systematic distortions among the available data sets and stochastic models that describe the observational residuals, are described. For parametric models, a relationship between the transformation parameters and the effects of datums and systematic distortions inherent among different height data types is established based on a least squares criterion. For stochastic models, the stochastic errors in GNSS/levelling/gravity data are evaluated, and a Helmert variance component estimation approach is introduced to refine weighting models. Finally, the proposed model is applied to determine the hybrid geoid in Linyi, China. The numerical results validate the capability and effectiveness of the proposed combined adjustment technique for hybrid geoid computations, revealing an achievable external accuracy of ±1.22 cm compared with GNSS/levelling measurements, which can be increased by 0.44 cm compared with classic adjustments of GNSS/levelling/geoid height data. Numéro de notice : A2021-913 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2020.1842642 Date de publication en ligne : 16/11/2020 En ligne : https://doi.org/10.1080/00396265.2020.1842642 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99316 [article]

Non-tidal loading of the Baltic Sea in Latvian GNSS time series / Diana Haritonova in Journal of applied geodesy, vol 15 n° 4 (October 2021)  

Public [article]  inJournal of applied geodesy > vol 15 n° 4 (October 2021) . - pp 293 - 304 Titre : Non-tidal loading of the Baltic Sea in Latvian GNSS time series Type de document : Article/Communication Auteurs : Diana Haritonova, Auteur Année de publication : 2021 Article en page(s) : pp 293 - 304 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] Baltique, mer [Termes IGN] coefficient de corrélation [Termes IGN] Continuously Operating Reference Station network [Termes IGN] données GNSS [Termes IGN] effet de charge [Termes IGN] Lettonie [Termes IGN] marégraphe [Termes IGN] niveau de la mer [Termes IGN] série temporelle [Termes IGN] station de référence [Termes IGN] surcharge océanique Résumé : (auteur) The objective of this study is to investigate the effect of the Baltic Sea non-tidal loading in the territory of Latvia using observations of the GNSS continuously operating reference stations (CORS) of LatPos, EUPOS®-Riga, EPN and EstPos networks. The GNSS station daily coordinate time series obtained in a double-difference (DD) mode were used. For representation of the sea level dynamics, the Latvian tide gauge records were used. Performed correlation analysis is based on yearly data sets of these observations for the period from 2012 up to 2020. The approach discloses how the non-tidal loading can induce variations in the time series of the regional GNSS station network. This paper increases understanding of the Earth’s surface displacements occurring due to the non-tidal loading effect in Latvia, and is intended to raise the importance and necessity of improved Latvian GNSS time series by removing loading effects. Numéro de notice : A2021-750 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2021-0024 Date de publication en ligne : 23/06/2021 En ligne : https://doi.org/10.1515/jag-2021-0024 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98719 [article]

Joint inversion of ground gravity data and satellite gravity gradients between Nepal and Bhutan: New insights on structural and seismic segmentation of the Himalayan arc / Rodolphe Cattin in Physics and chemistry of the Earth (A/B/C), vol 123 (October 2021)  

Permalink

Influence of aperiodic non-tidal atmospheric and oceanic loading deformations on the stochastic properties of global GNSS vertical land motion time series / Kevin Gobron in Journal of geophysical research : Solid Earth, vol 126 n° 9 (September 2021)  

Permalink

Tropospheric and range biases in Satellite Laser Ranging / Mateusz Drożdżewski in Journal of geodesy, vol 95 n° 9 (September 2021)  

Permalink

Establishing vertical separation models for vulnerable coastlines in developing territories / Cassandra Nanlal in Marine geodesy, vol 44 n° 5 (September 2021)  

Permalink

Temperature and humidity effects on CG-6 gravity observations / P. I. A. Weerasinghe in Journal of applied geodesy, vol 15 n° 3 (July 2021)  

Permalink

Comparison and evaluation of high-resolution marine gravity recovery via sea surface heights or sea surface slopes / Shengjun Zhang in Journal of geodesy, vol 95 n° 6 (June 2021)  

Permalink

Gravitational field modelling near irregularly shaped bodies using spherical harmonics: a case study for the asteroid (101955) Bennu / Blažej Bucha in Journal of geodesy, vol 95 n° 5 (May 2021)  

Permalink

High-resolution geoid modeling using least squares modification of Stokes and Hotine formulas in Colorado / Mustafa Serkan Işık in Journal of geodesy, vol 95 n° 5 (May 2021)  

Permalink

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)  

Permalink

Assessment of degree-2 order-1 gravitational changes from GRACE and GRACE Follow-on, Earth rotation, satellite laser ranging, and models / Jianli Chen in Journal of geodesy, vol 95 n° 4 (April 2021)  

Permalink