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Estimation of Lesser Antilles vertical velocity fields using a GNSS-PPP software comparison / Pierre Sakic-Kieffer (2022)  

Public contenu dans Beyond 100: The Next Century in Geodesy / J. Freymueller (2022)   Titre : Estimation of Lesser Antilles vertical velocity fields using a GNSS-PPP software comparison Type de document : Article/Communication Auteurs : Pierre Sakic-Kieffer, Auteur ; Benjamin Männel, Auteur ; Markus Bradke, Auteur ; et al., Auteur Editeur : Springer Nature Année de publication : 2022 Conférence : IAG 2019, General Assembly 08/07/2019 18/07/2019 Montreal Canada OA proceedings Importance : pp 169 - 180 Format : 16 x 24 cm Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] Antilles (îles des) [Termes IGN] champ de vitesse [Termes IGN] données GNSS [Termes IGN] positionnement ponctuel précis [Termes IGN] série temporelle [Termes IGN] subsidence Résumé : (auteur) Vertical land motion in insular areas is a crucial parameter to estimate the relative sea-level variations which impact coastal populations and activities. In subduction zones, it is also a relevant proxy to estimate the locking state of the plate interface. This motion can be measured using Global Navigation Satellite Systems (GNSS), such as the Global Positioning System (GPS). However, the influence of the processing software and the geodetic products (orbits and clock offsets) used for the solution remains barely considered for geophysics studies. In this study, we process GNSS observations of Guadeloupe and Martinique network (Lesser Antilles). It consists of 40 stations over a period of 18 years for the oldest site. We provide an updated vertical velocity field determined with two different geodetic software, namely EPOS (Gendt et al, GFZ analysis center of IGS–Annual Report. IGS 1996 Annual Report, pp 169–181, 1998) and GINS (Marty et al, GINS: the CNES/GRGS GNSS scientific software. In: 3rd International colloquium scientific and fundamental aspects of the Galileo programme, ESA proceedings WPP326, vol 31, pp 8–10, 2011) using their Precise Point Positioning modes. We used the same input models and orbit and clock offset products to maintain a maximum of consistency, and then compared the obtained results to get an estimation of the time series accuracy and the software influence on the solutions. General consistency between the solutions is noted, but significant velocity differences exist (at the mm/yr level) for some stations. Numéro de notice : C2019-079 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : sans En ligne : https://link.springer.com/chapter/10.1007/1345_2020_101 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102747

GLONASS FDMA data for RTK positioning: a five-system analysis / Andreas Brack in GPS solutions, vol 25 n° 1 (January 2021)  

Public [article]  inGPS solutions > vol 25 n° 1 (January 2021) . - n° 9 Titre : GLONASS FDMA data for RTK positioning: a five-system analysis Type de document : Article/Communication Auteurs : Andreas Brack, Auteur ; Benjamin Männel, Auteur ; Harald Schuh, Auteur Année de publication : 2021 Article en page(s) : n° 9 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] ambiguïté entière [Termes IGN] fréquence [Termes IGN] modèle ionosphérique [Termes IGN] positionnement cinématique en temps réel [Termes IGN] positionnement par GNSS [Termes IGN] résolution d'ambiguïté [Termes IGN] satellite GLONASS [Termes IGN] signal GLONASS Résumé : (auteur) The use of the GLONASS legacy signals for real-time kinematic positioning is considered. Due to the FDMA multiplexing scheme, the conventional CDMA observation model has to be modified to restore the integer estimability of the ambiguities. This modification has a strong impact on positioning capabilities. In particular, the ambiguity resolution performance of this model is clearly weaker than for CDMA systems, so that fast and reliable full ambiguity resolution is usually not feasible for standalone GLONASS, and adding GLONASS data in a multi-GNSS approach can reduce the ambiguity resolution performance of the combined model. Partial ambiguity resolution was demonstrated to be a suitable tool to overcome this weakness (Teunissen in GPS Solut 23(4):100, 2019). We provide an exhaustive formal analysis of the positioning precision and ambiguity resolution capabilities for short, medium, and long baselines in a multi-GNSS environment with GPS, Galileo, BeiDou, QZSS, and GLONASS. Simulations are used to show that with a difference test-based partial ambiguity resolution method, adding GLONASS data improves the positioning performance in all considered cases. Real data from different baselines are used to verify these findings. When using all five available systems, instantaneous centimeter-level positioning is possible on an 88.5 km baseline with the ionosphere weighted model, and on average, only 3.27 epochs are required for a long baseline with the ionosphere float model, thereby enabling near instantaneous solutions. Numéro de notice : A2021-009 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-020-01043-5 Date de publication en ligne : 24/10/2020 En ligne : https://doi.org/10.1007/s10291-020-01043-5 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96299 [article]

Reference system origin and scale realization within the future GNSS constellation “Kepler” / Susanne Glaser in Journal of geodesy, vol 94 n° 12 (December 2020)  

Public [article]  inJournal of geodesy > vol 94 n° 12 (December 2020) . - n° 117 Titre : Reference system origin and scale realization within the future GNSS constellation “Kepler” Type de document : Article/Communication Auteurs : Susanne Glaser, Auteur ; Grzegorz Michalak, Auteur ; Benjamin Männel, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : n° 117 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] centre de phase [Termes IGN] constellation Galileo [Termes IGN] constellation GNSS [Termes IGN] décorrélation [Termes IGN] géocentre [Termes IGN] International Terrestrial Reference Frame [Termes IGN] Kepler, Johannes [Termes IGN] orbite basse [Termes IGN] orbite terrestre [Termes IGN] orbitographie Résumé : (auteur) Currently, Global Navigation Satellite Systems (GNSS) do not contribute to the realization of origin and scale of combined global terrestrial reference frame (TRF) solutions due to present system design limitations. The future Galileo-like medium Earth orbit (MEO) constellation, called “Kepler”, proposed by the German Aerospace Center DLR, is characterized by a low Earth orbit (LEO) segment and the innovative key features of optical inter-satellite links (ISL) delivering highly precise range measurements and of optical frequency references enabling a perfect time synchronization within the complete constellation. In this study, the potential improvements of the Kepler constellation on the TRF origin and scale are assessed by simulations. The fully developed Kepler system allows significant improvements of the geocenter estimates (realized TRF origin in long-term). In particular, we find improvements by factors of 43 for the Z and of 8 for the X and Y component w. r. t. a contemporary MEO-only constellation. Furthermore, the Kepler constellation increases the reliability due to a complete de-correlation of the geocenter coordinates and the orbit parameters related to the solar radiation pressure modeling (SRP). However, biases in SRP modeling cause biased geocenter estimates and the ISL of Kepler can only partly compensate this effect. The realized scale enabling all Kepler features improves by 34% w. r. t. MEO-only. The dependency of the estimated satellite antenna phase center offsets (PCOs) upon the underlying TRF impedes a scale realization by GNSS. In order to realize the network scale with 1 mm accuracy, the PCOs have to be known within 2 cm for the MEO and 4 mm for the LEO satellites. Independently, the scale can be realized by estimating the MEO PCOs and by simultaneously fixing the LEO PCOs. This requires very accurate LEO PCOs; the simulations suggest them to be smaller than 1 mm in order to keep scale changes below 1 mm. Numéro de notice : A2020-736 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-020-01441-0 Date de publication en ligne : 19/11/2020 En ligne : https://doi.org/1https://doi.org/10.1007/s00190-020-01441-0 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96352 [article]

Integrated processing of ground- and space-based GPS observations: improving GPS satellite orbits observed with sparse ground networks / Wen Huang in Journal of geodesy, vol 94 n° 10 (October 2020)  

Public [article]  inJournal of geodesy > vol 94 n° 10 (October 2020) . - 13 p. Titre : Integrated processing of ground- and space-based GPS observations: improving GPS satellite orbits observed with sparse ground networks Type de document : Article/Communication Auteurs : Wen Huang, Auteur ; Benjamin Männel, Auteur ; Pierre Sakic-Kieffer, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : 13 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales [Termes IGN] modèle d'orbite [Termes IGN] orbite basse [Termes IGN] orbite précise [Termes IGN] orbitographie [Termes IGN] orbitographie par GNSS [Termes IGN] récepteur GPS [Termes IGN] station GPS Résumé : (auteur) The precise orbit determination (POD) of Global Navigation Satellite System (GNSS) satellites and low Earth orbiters (LEOs) are usually performed independently. It is a potential way to improve the GNSS orbits by integrating LEOs onboard observations into the processing, especially for the developing GNSS, e.g., Galileo with a sparse sensor station network and Beidou with a regional distributed operating network. In recent years, few studies combined the processing of ground- and space-based GNSS observations. The integrated POD of GPS satellites and seven LEOs, including GRACE-A/B, OSTM/Jason-2, Jason-3 and, Swarm-A/B/C, is discussed in this study. GPS code and phase observations obtained by onboard GPS receivers of LEOs and ground-based receivers of the International GNSS Service (IGS) tracking network are used together in one least-squares adjustment. The POD solutions of the integrated processing with different subsets of LEOs and ground stations are analyzed in detail. The derived GPS satellite orbits are validated by comparing with the official IGS products and internal comparison based on the differences of overlapping orbits and satellite positions at the day-boundary epoch. The differences between the GPS satellite orbits derived based on a 26-station network and the official IGS products decrease from 37.5 to 23.9 mm (34% improvement) in 1D-mean RMS when adding seven LEOs. Both the number of the space-based observations and the LEO orbit geometry affect the GPS satellite orbits derived in the integrated processing. In this study, the latter one is proved to be more critical. By including three LEOs in three different orbital planes, the GPS satellite orbits improve more than from adding seven well-selected additional stations to the network. Experiments with a ten-station and regional network show an improvement of the GPS satellite orbits from about 25 cm to less than five centimeters in 1D-mean RMS after integrating the seven LEOs. Numéro de notice : A2020-630 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-020-01424-1 Date de publication en ligne : 10/10/2020 En ligne : https://doi.org/10.1007/s00190-020-01424-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96049 [article]

Recent activities of the GGOS standing committee on Performance simulations and Architectural Trade-Offs (PLATO) / Benjamin Männel (2018)  

Public Titre : Recent activities of the GGOS standing committee on Performance simulations and Architectural Trade-Offs (PLATO) Type de document : Article/Communication Auteurs : Benjamin Männel, Auteur ; Daniela Thaller, Auteur ; Markus Rothacher, Auteur ; Johannes Böhm , Auteur ; Jurgen Müller, Auteur ; Susanne Glaser, Auteur ; Rolf Dach, Auteur ; Richard Biancale, Auteur ; Mathis Blossfeld, Auteur ; Alexander Kehm, Auteur ; Iván Herrera Pinzón, Auteur ; Franz Hofmann, Auteur ; Florian Andritsch, Auteur ; David Coulot , Auteur ; Arnaud Pollet , Auteur Editeur : Berlin, Heidelberg, Vienne, New York, ... : Springer Année de publication : 2018 Collection : International Association of Geodesy Symposia, ISSN 0939-9585 num. 149 Conférence : IAG 2017, joint IAG scientific assembly and IASPEI scientific assembly 30/07/2017 04/08/2017 Kobe Japon Proceedings Springer Importance : pp 161 - 164 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] Global Geodetic Observing System Résumé : (auteur) The Standing Committee on Performance Simulations and Architectural Trade-Offs (PLATO) was established by the Bureau of Networks and Observations of the Global Geodetic Observing System (GGOS) in order to support – by prior performance analysis – activities to reach the GGOS requirements for the accuracy and stability of the terrestrial reference frame. Based on available data sets and simulated observations for further stations and satellite missions the committee studies the impact of technique-specific improvements, new stations, and additional co-locations in space on reference frame products. Simulation studies carried out so far show the importance of the individual station performance and additional stations for satellite laser ranging, the perspectives for lunar laser ranging assuming additional stations and reflectors, and the significant impact of the new VGOS antennas. Significant progress is achieved in processing VLBI satellite tracking data. New insights in technique-specific error sources were derived based on real data from short baselines. Regarding co-location in space PLATO members confirmed that E-GRASP could fulfill the GGOS requirements with reaching a geocenter and scale accuracy and stability of 1 mm and 0.1 mm/year, respectively. Numéro de notice : C2017-063 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : 10.1007/1345_2018_30 Date de publication en ligne : 11/04/2018 En ligne : http://dx.doi.org/10.1007/1345_2018_30 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90562

Ionospheric corrections for single-frequency tracking of GNSS satellites by VLBI based on co-located GNSS / Benjamin Männel in Journal of geodesy, vol 90 n° 2 (February 2016)  

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Co-location of geodetic observation techniques in space / Benjamin Männel (2016)  

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