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Geodetic VLBI for precise orbit determination of Earth satellites: a simulation study / Grzegorz Klopotek in Journal of geodesy, vol 94 n° 6 (June 2020)  

Public [article]  inJournal of geodesy > vol 94 n° 6 (June 2020) Titre : Geodetic VLBI for precise orbit determination of Earth satellites: a simulation study Type de document : Article/Communication Auteurs : Grzegorz Klopotek, Auteur ; Thomas Hobiger, Auteur ; Rüdiger Haas, Auteur ; Toshimichi Otsubo, Auteur Année de publication : 2020 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] constellation GNSS [Termes IGN] données Galileo [Termes IGN] données Lageos [Termes IGN] données VGOS [Termes IGN] géocentre [Termes IGN] interférométrie à très grande base [Termes IGN] méthode de Monte-Carlo [Termes IGN] orbitographie [Termes IGN] paramètres d'orientation de la Terre [Termes IGN] quasar [Termes IGN] rotation de la Terre Résumé : (auteur) Recent efforts of tracking low Earth orbit and medium Earth orbit (MEO) satellites using geodetic very long baseline interferometry (VLBI) raise questions on the potential of this novel observation concept for space geodesy. Therefore, we carry out extensive Monte Carlo simulations in order to investigate the feasibility of geodetic VLBI for precise orbit determination (POD) of MEO satellites and assess the impact of quality and quantity of satellite observations on the derived geodetic parameters. The MEO satellites are represented in our study by LAGEOS-1/-2 and a set of Galileo satellites. The concept is studied on the basis of 3-day solutions in which satellite observations are included into real schedules of the continuous geodetic VLBI campaign 2017 (CONT17) as well as simulated schedules concerning the next-generation VLBI system, known as the VLBI Global Observing System (VGOS). Our results indicate that geodetic VLBI can perform on a comparable level as other space-geodetic techniques concerning POD of MEO satellites. For an assumed satellite observation precision better than 14.1 mm (47 ps), an average 3D orbit precision of 2.0 cm and 6.3 cm is found for schedules including LAGEOS-1/-2 and Galileo satellites, respectively. Moreover, geocenter offsets, which were so far out of scope for the geodetic VLBI analysis, are close to the detection limit for the simulations concerning VGOS observations of Galileo satellites, with the potential to further enhance the results. Concerning the estimated satellite orbits, VGOS leads to an average precision improvement of 80% with respect to legacy VLBI. In absolute terms and for satellite observation precision of 14.1 mm (47 ps), this corresponds to an average value of 17 mm and 7 mm concerning the 3D orbit scatter and precision of geocenter components, respectively. As shown in this study, a poor satellite geometry can degrade the derived Earth rotation parameters and VLBI station positions, compared to the quasar-only reference schedules. Therefore, careful scheduling of both quasar and satellite observations should be performed in order to fully benefit from this novel observation concept. Numéro de notice : A2020-342 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-020-01381-9 Date de publication en ligne : 11/06/2020 En ligne : https://doi.org/10.1007/s00190-020-01381-9 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95221 [article]

Geodetic VLBI with an artificial radio source on the Moon : a simulation study / Grzegorz Klopotek in Journal of geodesy, vol 92 n° 5 (May 2018)  

Public [article]  inJournal of geodesy > vol 92 n° 5 (May 2018) . - pp 457 – 469 Titre : Geodetic VLBI with an artificial radio source on the Moon : a simulation study Type de document : Article/Communication Auteurs : Grzegorz Klopotek, Auteur ; Thomas Hobiger, Auteur ; Rüdiger Haas, Auteur Année de publication : 2018 Article en page(s) : pp 457 – 469 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] C++ [Termes IGN] émetteur [Termes IGN] interférométrie à très grande base [Termes IGN] Lune [Termes IGN] méthode de Monte-Carlo [Termes IGN] modèle de simulation [Termes IGN] modèle stochastique [Termes IGN] simulation Résumé : (Auteur) We perform extensive simulations in order to assess the accuracy with which the position of a radio transmitter on the surface of the Moon can be determined by geodetic VLBI. We study how the quality and quantity of geodetic VLBI observations influence these position estimates and investigate how observations of such near-field objects affect classical geodetic parameters like VLBI station coordinates and Earth rotation parameters. Our studies are based on today’s global geodetic VLBI schedules as well as on those designed for the next-generation geodetic VLBI system. We use Monte Carlo simulations including realistic stochastic models of troposphere, station clocks, and observational noise. Our results indicate that it is possible to position a radio transmitter on the Moon using today’s geodetic VLBI with a two-dimensional horizontal accuracy of better than one meter. Moreover, we show that the next-generation geodetic VLBI has the potential to improve the two-dimensional accuracy to better than 5 cm. Thus, our results lay the base for novel observing concepts to improve both lunar research and geodetic VLBI. Numéro de notice : A2018-149 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1072-4 Date de publication en ligne : 27/10/2017 En ligne : https://doi.org/10.1007/s00190-017-1072-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89760 [article]