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Absolute field calibration for multi-GNSS receiver antennas at ETH Zurich / Daniel Willi in GPS solutions, vol 24 n° 1 (January 2020)  

Public [article]  inGPS solutions > vol 24 n° 1 (January 2020) Titre : Absolute field calibration for multi-GNSS receiver antennas at ETH Zurich Type de document : Article/Communication Auteurs : Daniel Willi, Auteur ; Simon Lutz, Auteur ; Elmar Brockmann, Auteur ; Markus Rothacher, Auteur Année de publication : 2020 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] antenne Galileo [Termes IGN] antenne GNSS [Termes IGN] antenne GPS [Termes IGN] centre de phase [Termes IGN] données Galileo [Termes IGN] données GPS [Termes IGN] données multicapteurs [Termes IGN] étalonnage au sol [Termes IGN] étalonnage d'instrument [Termes IGN] étalonnage des données [Termes IGN] international GPS service for geodynamics [Termes IGN] mesurage de phase [Termes IGN] récepteur GNSS [Termes IGN] robot [Termes IGN] signal GNSS [Termes IGN] Zurich (Suisse) Résumé : (Auteur) ETH Zurich developed an absolute GNSS antenna calibration system based on measurements taken in the field. An industrial robot is used to rotate and tilt the antenna to be calibrated. This procedure ensures good coverage of the antenna hemisphere and reduces systematic errors. The calibration system at ETH Zurich is validated by a direct comparison of the obtained calibrations with calibrations from the anechoic chamber method (University of Bonn) and from another absolute field calibration method (Geo++® GmbH). Calibrations by ETH Zurich agree on the sub-millimeter level with both reference calibrations. A second validation was conducted using real measurements on short baselines. Data were acquired on four stations in direct vicinity and processed using different phase center correction models. The experiment shows that individual corrections of ETH Zurich reduce the residuals in the coordinate domain when compared to type-mean calibrations of the International GNSS Service (IGS). However, residual biases between GPS and Galileo coordinates remain. These biases are efficiently reduced when using the new type-mean calibrations from the IGS that include calibration values for all GNSS, including Galileo. The ETH Zurich calibration system is proven to deliver meaningful calibrations that agree with other calibrations on the millimeter level in the azimuth and elevation domain. The field validation shows evidence that the consistency of the Galileo and GPS calibration should be further enhanced by performing a combined GPS and Galileo analysis, which is not yet implemented. Numéro de notice : A2020-020 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-019-0941-0 Date de publication en ligne : 19/12/2019 En ligne : https://doi.org/10.1007/s10291-019-0941-0 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94460 [article]

CODE’s new ultra-rapid orbit and ERP products for the IGS / Simon Lutz in GPS solutions, vol 20 n° 2 (April 2016)  

Public [article]  inGPS solutions > vol 20 n° 2 (April 2016) . - pp 239 - 250 Titre : CODE’s new ultra-rapid orbit and ERP products for the IGS Type de document : Article/Communication Auteurs : Simon Lutz, Auteur ; Gerhard Beutler, Auteur ; Stefan Schaer, Auteur ; Rolf Dach, Auteur ; Adrian Jäggi, Auteur Année de publication : 2016 Article en page(s) : pp 239 - 250 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] Bernese [Termes IGN] international GPS service for geodynamics [Termes IGN] orbite [Termes IGN] rotation de la Terre Résumé : (Auteur) The International GNSS Service (IGS) issues four sets of so-called ultra-rapid products per day, which are based on the contributions of the IGS Analysis Centers. The traditional (“old”) ultra-rapid orbit and earth rotation parameters (ERP) solution of the Center for Orbit Determination in Europe (CODE) was based on the output of three consecutive 3-day long-arc rapid solutions. Information from the IERS Bulletin A was required to generate the predicted part of the old CODE ultra-rapid product. The current (“new”) product, activated in November 2013, is based on the output of exactly one multi-day solution. A priori information from the IERS Bulletin A is no longer required for generating and predicting the orbits and ERPs. This article discusses the transition from the old to the new CODE ultra-rapid orbit and ERP products and the associated improvement in reliability and performance. All solutions used in this article were generated with the development version of the Bernese GNSS Software. The package was slightly extended to meet the needs of the new CODE ultra-rapid generation. Numéro de notice : A2016-613 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-014-0432-2 En ligne : http://dx.doi.org/10.1007/s10291-014-0432-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81813 [article]

Impact of the arc length on GNSS analysis results / Simon Lutz in Journal of geodesy, vol 90 n° 4 (April 2016)  

Public [article]  inJournal of geodesy > vol 90 n° 4 (April 2016) . - pp 365 - 378 Titre : Impact of the arc length on GNSS analysis results Type de document : Article/Communication Auteurs : Simon Lutz, Auteur ; Michael Meindl, Auteur ; Peter Steigenberger, Auteur ; Gerhard Beutler, Auteur ; Krzysztof Sosnica, Auteur ; Stefan Schaer, Auteur ; Rolf Dach, Auteur ; Daniel Arnold, Auteur ; Daniela Thaller, Auteur ; Adrian Jäggi, Auteur Année de publication : 2016 Article en page(s) : pp 365 - 378 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] géocentre [Termes IGN] mouvement du pôle [Termes IGN] orientation de la Terre [Vedettes matières IGN] Traitement de données GNSS Résumé : (auteur) Homogeneously reprocessed combined GPS/GLONASS 1- and 3-day solutions from 1994 to 2013, generated by the Center for Orbit Determination in Europe (CODE) in the frame of the second reprocessing campaign REPRO-2 of the International GNSS Service, as well as GPS- and GLONASS-only 1- and 3-day solutions for the years 2009 to 2011 are analyzed to assess the impact of the arc length on the estimated Earth Orientation Parameters (EOP, namely polar motion and length of day), on the geocenter, and on the orbits. The conventional CODE 3-day solutions assume continuity of orbits, polar motion components, and of other parameters at the day boundaries. An experimental 3-day solution, which assumes continuity of the orbits, but independence from day to day for all other parameters, as well as a non-overlapping 3-day solution, is included into our analysis. The time series of EOPs, geocenter coordinates, and orbit misclosures, are analyzed. The long-arc solutions were found to be superior to the 1-day solutions: the RMS values of EOP and geocenter series are typically reduced between 10 and 40 %, except for the polar motion rates, where RMS reductions by factors of 2–3 with respect to the 1-day solutions are achieved for the overlapping and the non-overlapping 3-day solutions. In the low-frequency part of the spectrum, the reduction is even more important. The better performance of the orbits of 3-day solutions with respect to 1-day solutions is also confirmed by the validation with satellite laser ranging. Numéro de notice : A2016-250 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0878-1 Date de publication en ligne : 24/12/2015 En ligne : https://doi.org/10.1007/s00190-015-0878-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80758 [article]

Impact of Earth radiation pressure on GPS position estimates / C. Rodriguez-Solano in Journal of geodesy, vol 86 n° 5 (May 2012)  

Public [article]  inJournal of geodesy > vol 86 n° 5 (May 2012) . - pp 309 - 317 Titre : Impact of Earth radiation pressure on GPS position estimates Type de document : Article/Communication Auteurs : C. Rodriguez-Solano, Auteur ; Urs Hugentobler, Auteur ; Peter Steigenberger, Auteur ; Simon Lutz, Auteur Année de publication : 2012 Article en page(s) : pp 309 - 317 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] bilan radiatif [Termes IGN] orbitographie [Termes IGN] positionnement par GPS [Termes IGN] précision du positionnement [Termes IGN] rayonnement terrestre [Termes IGN] signal GPS Résumé : (Auteur) GPS satellite orbits available from the International GNSS Service (IGS) show a consistent radial bias of up to several cm and a particular pattern in the Satellite Laser Ranging (SLR) residuals, which are suggested to be related to radiation pressure mismodeling. In addition, orbit-related frequencies were identified in geodetic time series such as apparent geocenter motion and station displacements derived from GPS tracking data. A potential solution to these discrepancies is the inclusion of Earth radiation pressure (visible and infrared) modeling in the orbit determination process. This is currently not yet considered by all analysis centers contributing to the IGS final orbits. The acceleration, accounting for Earth radiation and satellite models, is introduced in this paper in the computation of a global GPS network (around 200 IGS sites) adopting the analysis strategies from the Center for Orbit Determination in Europe (CODE). Two solutions covering 9 years (2000–2008) with and without Earth radiation pressure were computed and form the basis for this study. In previous studies, it has been shown that Earth radiation pressure has a non-negligible effect on the GPS orbits, mainly in the radial component. In this paper, the effect on the along-track and cross-track components is studied in more detail. Also in this paper, it is shown that Earth radiation pressure leads to a change in the estimates of GPS ground station positions, which is systematic over large regions of the Earth. This observed “deformation” of the Earth is towards North–South and with large scale patterns that repeat six times per GPS draconitic year (350 days), reaching a magnitude of up to 1 mm. The impact of Earth radiation pressure on the geocenter and length of day estimates was also investigated, but the effect is found to be less significant as compared to the orbits and position. Numéro de notice : A2012-240 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-011-0517-4 Date de publication en ligne : 13/10/2011 En ligne : https://doi.org/10.1007/s00190-011-0517-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31686 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-2012051	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Evaluation of the impact of atmospheric pressure loading modeling on GNSS data analysis / Rolf Dach in Journal of geodesy, vol 85 n° 2 (February 2011)  

Public [article]  inJournal of geodesy > vol 85 n° 2 (February 2011) . - pp 75 - 91 Titre : Evaluation of the impact of atmospheric pressure loading modeling on GNSS data analysis Type de document : Article/Communication Auteurs : Rolf Dach, Auteur ; Johannes Böhm , Auteur ; Simon Lutz, Auteur ; Peter Steigenberger, Auteur ; Gerhard Beutler, Auteur Année de publication : 2011 Article en page(s) : pp 75 - 91 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] analyse de données [Termes IGN] données GNSS [Termes IGN] impact sur les données [Termes IGN] International GNSS Service [Termes IGN] série temporelle [Termes IGN] signal GNSS [Termes IGN] surcharge atmosphérique [Termes IGN] variation saisonnière Résumé : (Auteur) In recent years, several studies have demonstrated the sensitivity of Global Navigation Satellite System (GNSS) station time series to displacements caused by atmospheric pressure loading (APL). Different methods to take the APL effect into account are used in these studies: applying the corrections from a geophysical model on weekly mean estimates of station coordinates, using observation-level corrections during data analysis, or solving for regression factors between the station displacement and the local pressure. The Center for Orbit Determination in Europe (CODE) is one of the global analysis centers of the International GNSS Service (IGS). The current quality of the IGS products urgently asks to consider this effect in the regular processing scheme. However, the resulting requirements for an APL model are demanding with respect to quality, latency, and—regarding the reprocessing activities—availability over a long time interval (at least from 1994 onward). The APL model of Petrov and Boy (J Geophys Res 109:B03405, 2004) is widely used within the VLBI community and is evaluated in this study with respect to these criteria. The reprocessing effort of CODE provides the basis for validating the APL model. The data set is used to solve for scaling factors for each station to evaluate the geophysical atmospheric non-tidal loading model. A consistent long-term validation of the model over 15 years, from 1994 to 2008, is thus possible. The time series of 15 years allows to study seasonal variations of the scaling factors using the dense GNSS tracking network of the IGS. By interpreting the scaling factors for the stations of the IGS network, the model by (2004) is shown to meet the expectations concerning the order of magnitude of the effect at individual stations within the uncertainty given by the GNSS data processing and within the limitations due to the model itself. The repeatability of station coordinates improves by 20% when applying the effect directly on the data analysis and by 10% when applying a post-processing correction to the resulting weekly coordinates compared with a solution without taking APL into account. Numéro de notice : A2011-067 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-010-0417-z Date de publication en ligne : 22/10/2010 En ligne : https://doi.org/10.1007/s00190-010-0417-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30848 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
266-2011021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Better weather prediction using GPS: water vapor tomography in the Swiss Alps / Simon Lutz in GPS world, vol 21 n° 7 (July 2010)

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High-resolution GPS tomography in view of hydrological hazard assessment / Simon Lutz (2009)  

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GPS Tomography and Remote Sensing Techniques for Water Vapor Determination in the ESCOMPTE Campaign / Beat Bürki (2004)

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