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Tropospheric delay modelling for the EGNOS augmentation system / Kamil Kazmierski in Survey review, vol 49 n° 357 (December 2017)  

Public [article]  inSurvey review > vol 49 n° 357 (December 2017) . - pp 399 - 407 Titre : Tropospheric delay modelling for the EGNOS augmentation system Type de document : Article/Communication Auteurs : Kamil Kazmierski, Auteur ; Marcelo C. Santos, Auteur ; Jaroslaw Bosy, Auteur Année de publication : 2017 Article en page(s) : pp 399 - 407 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] données météorologiques [Termes IGN] erreur systématique [Termes IGN] European Geostationary Navigation Overlay Service [Termes IGN] positionnement par EGNOS [Termes IGN] retard troposphérique [Termes IGN] retard troposphérique zénithal Résumé : (auteur) Tropospheric delay is one of the deleterious factors limiting the accuracy of the precise Global Navigation Satellite Systems positioning. The value of delay depends on the path through which a signal has to follow in the subsurface layers of the atmosphere. Tropospheric delay models are developed to overcome this limitation. Among them one can find UNB, TropGrid or IGGtrop models. In this paper, we adjusted the UNB3m model to the actual meteorological parameters from Europe. A new model was called UNBe.eu covering the EGNOS augmentation system area. The use of meteorological observations helped us to decrease the bias for more than 70% of reference radio sounding locations. Still, 30% of reference sites depicted a lack of any improvements of the ZTD estimation with regard to the newly established model. Therefore, this study puts forward a need for a deeper investigation of the discussed issue. Numéro de notice : A2017-754 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/00396265.2016.1180798 En ligne : https://doi.org/10.1080/00396265.2016.1180798 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89102 [article]

Real-time precise point positioning augmented with high-resolution numerical weather prediction model / Karina Wilgan in GPS solutions, vol 21 n° 3 (July 2017)  

Public [article]  inGPS solutions > vol 21 n° 3 (July 2017) . - pp 1341 – 1353 Titre : Real-time precise point positioning augmented with high-resolution numerical weather prediction model Type de document : Article/Communication Auteurs : Karina Wilgan, Auteur ; Tomasz Hadas, Auteur ; Pawel Hordyniec, Auteur ; Jaroslaw Bosy, Auteur Année de publication : 2017 Article en page(s) : pp 1341 – 1353 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] analyse diachronique [Termes IGN] Pologne [Termes IGN] positionnement ponctuel précis [Termes IGN] prévision météorologique [Termes IGN] propagation troposphérique [Termes IGN] réseau permanent EUREF [Termes IGN] retard troposphérique [Termes IGN] retard troposphérique zénithal [Termes IGN] station GNSS [Termes IGN] temps réel Résumé : (auteur) The tropospheric delay is one of the major error sources in precise point positioning (PPP), affecting the accuracy and precision of estimated coordinates and convergence time, which raises demand for a reliable tropospheric model, suitable to support PPP. In this study, we investigate the impact of three tropospheric models and mapping functions regarding position accuracy and convergence time. We propose a routine to constrain the tropospheric estimates, which we implemented in the in-house developed real-time PPP software. We take advantage of the high spatial resolution (4 × 4 km2) numerical weather prediction Weather Research and Forecasting (WRF) model and near real-time GNSS data combined by the least-squares collocation estimation to reconstruct the tropospheric delays. We also present mapping functions calculated from the WRF model using the ray-tracing technique. The performance tests are conducted on 14 Polish EUREF Permanent Network (EPN) stations during 3 weeks of different tropospheric conditions: calm, standard and severe. We consider six GNSS data processing variants, including two commonly used variants using a priori ZTD and mapping functions from UNB3m and VMF1-FC models, one with a priori ZTD and mapping functions calculated directly from WRF model and three variants using the aforementioned mapping functions but with ZTD model based on GNSS and WRF data used as a priori troposphere and to constrain tropospheric estimates. The application of a high-resolution GNSS/WRF-based ZTD model and mapping functions results in the best agreement with the official EPN coordinates. In both static and kinematic modes, this approach results in an average reduction of 3D bias by 20 and 10 mm, respectively, but an increase of 3D SDs by 1.5 and 4 mm, respectively. The application of high-resolution tropospheric model also shortens the convergence time, for example, for a 10 cm convergence level, from 67 to 58 min for the horizontal components and from 79 to 63 min for the vertical component. Numéro de notice : A2017-444 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-017-0617-6 En ligne : https://doi.org/10.1007/s10291-017-0617-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86368 [article]

Reference frames and reference networks / Jaroslaw Bosy in Geodesy and cartography, vol 64 n° 2 (December 2015)  

Public [article]  inGeodesy and cartography > vol 64 n° 2 (December 2015) . - pp 147 - 176 Titre : Reference frames and reference networks Type de document : Article/Communication Auteurs : Jaroslaw Bosy, Auteur ; Jan Krynski, Auteur Année de publication : 2015 Article en page(s) : pp 147 - 176 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux [Termes IGN] European Terrestrial Reference System 1989 [Termes IGN] Pologne [Termes IGN] réseau géodésique local [Termes IGN] système de référence local Résumé : (auteur) The summary of research activities concerning reference frames and reference networks performed in Poland in a period of 2011-2014 is presented. It contains the results of research on implementation of IUGG2011 and IAU2012 resolutions on reference systems, implementation of the ETRS89 in Poland, operational work of permanent IGS/ EUREF stations in Poland, operational work of ILRS laser ranging station in Poland, active GNSS station networks in Poland, maintenance of vertical control in Poland, maintenance and modernization of gravity control, and maintenance of magnetic control in Poland. The bibliography of the related works is given in references. Numéro de notice : A2015--016 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/geocart-2015-0011 En ligne : http://dx.doi.org/10.1515/geocart-2015-0011 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80810 [article]

Near real-time estimation of water vapour in the troposphere using ground GNSS and the meteorological data / Jaroslaw Bosy in Annales Geophysicae, vol 30 n° 9 (September 2012)  

Public [article]  inAnnales Geophysicae > vol 30 n° 9 (September 2012) . - 13 p. ; pp 1379 - 1391 Titre : Near real-time estimation of water vapour in the troposphere using ground GNSS and the meteorological data Type de document : Article/Communication Auteurs : Jaroslaw Bosy, Auteur ; J. Kaplon, Auteur ; Witold Rohm, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : 13 p. ; pp 1379 - 1391 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] données météorologiques [Termes IGN] EUPOS [Termes IGN] modèle atmosphérique [Termes IGN] Pologne [Termes IGN] propagation troposphérique [Termes IGN] surveillance météorologique [Termes IGN] teneur en vapeur d'eau [Termes IGN] tomographie Résumé : (Auteur) The near real-time (NRT) high resolution water vapour distribution models can be constructed based on GNSS observations delivered from Ground Base Augmentation Systems (GBAS) and ground meteorological data. Since 2008 in the territory of Poland, a GBAS system called ASGEUPOS (Active Geodetic Network) has been operating. This paper addresses the problems concerning construction of the NRT model of water vapour distribution in the troposphere near Poland. The first section presents all available GNSS and ground meteorological stations in the area of Poland and neighbouring countries. In this section, data feeding scheme is discussed, together with timeline and time resolution. The high consistency between measured and interpolated temperature value is shown, whereas some discrepancy in the pressure is observed. In the second section, the NRT GNSS data processing strategy of ASG-EUPOS network is discussed. Preliminary results show fine alignment of the obtained Zenith Troposphere Delays (ZTDs) with reference data from European Permanent Network (EPN) processing center. The validation of NRT troposphere products against daily solution shows 15mm standard deviation of obtained ZTD differences. The last section presents the first results of 2-D water vapour distribution above the GNSS network and application of the tomographic model to 3-D distribution of water vapour in the atmosphere. The GNSS tomography model, working on the simulated data from numerical forecast model, shows high consistency with the reference data (by means of standard deviation 4mmkm1 or 4 ppm), however, noise analysis shows high solution sensitivity to errors in observations. The discrepancy for real data preliminary solution (measured as a mean standard deviation) between reference NWP data and tomography data was on the level of 9mmkm1 (or 9 ppm) in terms of wet refractivity. Numéro de notice : A2012-749 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.5194/angeo-30-1379-2012 Date de publication en ligne : 27/09/2012 En ligne : https://doi.org/10.5194/angeo-30-1379-2012 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33601 [article]