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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]

Determination of the orthometric height difference based on optical fiber frequency transfer technique / Anh The Hoang in Geodesy and Geodynamics, vol 12 n° 6 (November 2021)  

Public [article]  inGeodesy and Geodynamics > vol 12 n° 6 (November 2021) . - pp 405 - 412 Titre : Determination of the orthometric height difference based on optical fiber frequency transfer technique Type de document : Article/Communication Auteurs : Anh The Hoang, Auteur ; Ziyu Shen, Auteur ; Wenbin Shen, Auteur Année de publication : 2021 Article en page(s) : pp 405 - 412 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie [Termes IGN] altimétrie [Termes IGN] altitude orthométrique [Termes IGN] coefficient de géopotentiel [Termes IGN] fibre optique [Termes IGN] fréquence [Termes IGN] précision centimétrique Mots-clés libres : optical fiber frequency transfer Résumé : (auteur) The development of remote frequency transfer techniques, especially the appearance of optical clocks with unprecedented stability, has prompted geoscientists to study their applications in geodesy. Using remote frequency transfer technique, by frequency comparison of two optical clocks at two points P and Q connected by optical fibers, one can measure the signal's frequency shift between them, and the geopotential difference between them can be determined based on the gravity frequency shift equation. Given the orthometric height of P, the orthometric height of Q can be determined. Since the present stability of the optical clock has achieved 1 × 10−18 or better and comparing the frequency transfer via optical fiber provides stability at 10−19 level, the optical clock network enables determining the orthometric height at centimeter-level. This study provides a formulation to determine the height difference at one-centimeter level between two points on the ground based on the optical fiber frequency transfer technique. Numéro de notice : A2021-945 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1016/j.geog.2021.08.003 Date de publication en ligne : 22/09/2021 En ligne : https://doi.org/10.1016/j.geog.2021.08.003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99757 [article]