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The international DORIS service contribution to ITRF2020 / Guilhem Moreaux in Advances in space research, vol inconnu (2023)
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Titre : The international DORIS service contribution to ITRF2020 Type de document : Article/Communication Auteurs : Guilhem Moreaux, Auteur ; Franck G. Lemoine, Auteur ; Hugues Capdeville, Auteur ; Michiel Otten, Auteur ; Petr Štěpánek, Auteur ; Jérôme Saunier , Auteur ; Pascale Ferrage, Auteur
Année de publication : 2023 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] combinaison au niveau des observations
[Termes IGN] DORIS
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] mouvement du pôleRésumé : (autuer) For the realization of the 2020 International Terrestrial Reference Frame (ITRF2020), the International DORIS Service delivered to the International Earth Rotation and Reference Systems Service (IERS) a set of 1456 weekly solution files from 1993.0 to 2021.0 including station coordinates and Earth orientation parameters (EOPs). The data come from fourteen DORIS satellites: TOPEX/Poseidon, SPOT-2, SPOT-3, SPOT-4, SPOT-5, Envisat, Jason-1, Jason-2, Cryosat-2, Saral, HY-2A, Jason-3, Sentinel-3A and Sentinel-3B. In their processing, the four analysis centers which contributed to the DORIS combined solution used the latest time variable gravity models, the new mean pole and diurnal-subdiurnal tidal EOP models recommended by IERS. In addition, all the analysis centers included in their processing precise SPOT-5 solar panel angle values and quaternions for, at least, the Jason satellites. Furthermore, a new Alcatel phase center variation model was implemented for the ITRF2020 processing. The main objective of this study is to present the combination process and to analyze the impact of the new modeling on the performance of the new combined solution. Comparisons with the IDS contribution to ITRF2014 show that i) the application of the new phase center variations for the Alcatel DORIS ground antennas in the data processing combined with the gradual replacement over time of the Alcatel by Starec antennas implies a scale drift from 1993.0 to 2002.5 and ii) thanks to a better modeling of the surface forces on the satellites, the new combined solution shows smaller annual and 118-day signals in the geocenter. A new DORIS terrestrial reference frame was computed to evaluate the intrinsic quality of the new combined solution. That evaluation shows that over almost the full time span the intrinsic IDS scale values lie in a range of mm. After mid-2008, the new DORIS reference frame has an internal position consistency in North-East-Up better than 7.5 mm. Numéro de notice : A2023-083 Affiliation des auteurs : IGN+Ext (2020- ) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2022.07.012 Date de publication en ligne : 15/07/2022 En ligne : https://doi.org/10.1016/j.asr.2022.07.012 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101349
in Advances in space research > vol inconnu (2023)[article]Iterative data assimilation approach for the refinement of marine geoid models using sea surface height and dynamic topography datasets / Sander Varbla in Journal of geodesy, vol 97 n° 3 (March 2023)
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Titre : Iterative data assimilation approach for the refinement of marine geoid models using sea surface height and dynamic topography datasets Type de document : Article/Communication Auteurs : Sander Varbla, Auteur ; Artu Ellmann, Auteur Année de publication : 2023 Article en page(s) : n° 24 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] collocation par moindres carrés
[Termes IGN] données altimétriques
[Termes IGN] geoïde marin
[Termes IGN] hauteurs de mer
[Termes IGN] itération
[Termes IGN] levé gravimétrique
[Termes IGN] simulation hydrodynamiqueRésumé : (auteur) The modelling errors of marine geoid models may reach up to a few decimetres in the shorter wavelength spectrum due to gravity data void areas and/or inaccurate data. Various data acquisition methods can provide sea surface heights more accurately. Similarly, hydrodynamic model data in conjunction with tide gauge readings allow the derivation of reliable dynamic topography. Geometrical marine geoid heights, independent of the usual gravity-based marine geoid models, can be obtained by removing the estimated dynamic topography from sea surface height measurements. This study exploits such geometry information to refine marine geoid models. A data assimilation approach was developed that iteratively combines sea surface height and dynamic topography datasets with an initial gravimetric geoid model. A case study is presented using sea surface heights from shipborne GNSS campaigns and an airborne laser scanning survey for refining the EIGEN-6C4 global geopotential model. Comparisons with a high-resolution regional marine geoid model reveal that the initial discrepancies of up to around two decimetres reduce to sub-decimetre within the study area. It is concluded that the developed iterative data assimilation approach can significantly improve the accuracy of marine geoid models, especially in regions where gravity data are of poor quality or unavailable. Numéro de notice : A2023-157 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-023-01711-7 Date de publication en ligne : 15/03/2023 En ligne : https://doi.org/10.1007/s00190-023-01711-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102846
in Journal of geodesy > vol 97 n° 3 (March 2023) . - n° 24[article]Comparison of different global DTMs and GGMs over Sri Lanka / Weeramuni Javana Praboni De Silva in Journal of applied geodesy, vol 17 n° 1 (January 2023)
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Titre : Comparison of different global DTMs and GGMs over Sri Lanka Type de document : Article/Communication Auteurs : Weeramuni Javana Praboni De Silva, Auteur ; Herath Mudiyanselage Indika Prasanna, Auteur Année de publication : 2023 Article en page(s) : pp 29 - 38 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] géoïde altimétrique
[Termes IGN] MERIT
[Termes IGN] MNS ASTER
[Termes IGN] MNS SRTM
[Termes IGN] modèle de géopotentiel
[Termes IGN] Sri Lanka
[Vedettes matières IGN] AltimétrieRésumé : (auteur) Digital Elevation Models (DEMs) are real-world geographical databases that are important in studying many Earth related topics. Because the vertical accuracy of global DEMs differs across regions due to various reasons, acquiring reliable heights for a region using global height models is crucial. The objective of this study is to compare and assess the most reliable global height model for Sri Lanka. The official height system in Sri Lanka is the Mean Sea Level (MSL) based orthometric height system. In this study, the quality of ASTER, SRTM, NASADEM, MERIT, and DEMs compiled from digitized contour data of Sri Lanka was evaluated using the known heights of the Fundamental Benchmarks (FBMs) of Sri Lanka. In addition, recently published high-resolution Global Geopotential Models (GGMs) were used for the accuracy assessments of gravity related quantities computed using DEMs. The SGG-UGM-2 GGM, which showed the minimum STD and RMSE of geoid undulation difference was found as the best fit GGM over Sri Lanka. It was found that the NASADEM at its highest resolution, which gave the lowest RMSE of 2.954 m was the best global DEM for Sri Lanka. Numéro de notice : A2023-050 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2022-0026 Date de publication en ligne : 07/11/2022 En ligne : https://doi.org/10.1515/jag-2022-0026 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102376
in Journal of applied geodesy > vol 17 n° 1 (January 2023) . - pp 29 - 38[article]Modeling the gravitational effects of ocean tide loading at coastal stations in the China earthquake gravity network based on GOTL software / Chuandong Zhu in Journal of applied geodesy, vol 17 n° 1 (January 2023)
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Titre : Modeling the gravitational effects of ocean tide loading at coastal stations in the China earthquake gravity network based on GOTL software Type de document : Article/Communication Auteurs : Chuandong Zhu, Auteur ; Liuqing Pang, Auteur ; Didi Sheng, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : pp 15 - 27 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] champ de pesanteur local
[Termes IGN] Chine
[Termes IGN] fonction de Green
[Termes IGN] littoral
[Termes IGN] marée océanique
[Termes IGN] modèle de géopotentiel
[Termes IGN] modèle numérique de surface
[Termes IGN] surcharge océaniqueRésumé : (auteur) The gravitational effects of ocean tide loading, which are one of the main factors affecting gravity measurements, consist of three components: (1) direct attraction from the tidal water masses, (2) radial displacement of the observing station due to the tidal load, and (3) internal redistribution of masses due to crustal deformation. In this study, software for gravitational effects of ocean tide loading was developed by evaluating a convolution integral between the ocean tide model and Green’s functions that describe the response of the Earth to tide loading. The effects of three-dimensional station coordinates, computational grid patterns, ocean tide models, Green’s functions, coastline, and local tide gauge were comprehensively considered in the programming process. Using a larger number of high-precision coastlines, ocean tide models, and Green’s functions, the reliability and applicability of the software were analyzed at coastal stations in the China Earthquake Gravity Network. The software can provide the amplitude and phase for ocean tide loading and produce a predicted gravity time series. The results can effectively reveal the variation characteristics of ocean tide loading in space and time. The computational gravitational effects of ocean tide loading were compared and analyzed for different ocean tide models and Green’s functions. The results show that different ocean tide models and Green’s functions have certain effects on the calculated values of loading gravity effects. Furthermore, a higher-precision local ocean tide model, digital elevation model, and local tidal gauge record can be further imported into our software to improve the accuracy of loading gravity effects in the global and local zones. The software is easy to operate and can provide a comprehensive platform for correcting the gravitational effects of ocean tide loading at stations in the China Earthquake Gravity Network. Numéro de notice : A2023-112 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2022-0023 Date de publication en ligne : 03/11/2022 En ligne : https://doi.org/10.1515/jag-2022-0023 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102471
in Journal of applied geodesy > vol 17 n° 1 (January 2023) . - pp 15 - 27[article]Détermination de la déviation de la verticale sur le barrage de Plan d’Aval, sans aucune instrumentation spéciale, avec une précision de 0,4 mgon / Thomas Touzé in XYZ, n° 173 (décembre 2022)
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Titre : Détermination de la déviation de la verticale sur le barrage de Plan d’Aval, sans aucune instrumentation spéciale, avec une précision de 0,4 mgon Type de document : Article/Communication Auteurs : Thomas Touzé, Auteur Année de publication : 2022 Article en page(s) : pp 30 - 34 Note générale : Bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] barrage
[Termes IGN] déviation de la verticale
[Termes IGN] données GNSS
[Termes IGN] incertitude de position
[Termes IGN] lever tachéométrique
[Termes IGN] surveillance d'ouvrageRésumé : (Editeur) Dans cet article, nous proposons une nouvelle méthode de détermination de la déviation de la verticale à partir de mesures tachéométriques corrigées de la réfraction et de lignes de base GNSS. Si l’état de l’art est bien respecté, une précision de l’ordre de 0,3 mgon (1’’) sur une visée de 1 km semble tout à fait atteignable. Nous présentons ainsi les résultats obtenus lors de la surveillance de deux barrages EDF dans les Alpes ayant permis de déterminer la déviation de la verticale avec une incertitude à 68 % de 0,4 mgon (1.3’’) et en cohérence avec la valeur déduite du géoïde. Numéro de notice : A2022-914 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueNat DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102277
in XYZ > n° 173 (décembre 2022) . - pp 30 - 34[article]Réservation
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