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GNSS-WARP software for real-time precise point positioning / Tomasz Hadas in Artificial satellites, vol 50 n° 2 (June 2015)  

Public [article]  inArtificial satellites > vol 50 n° 2 (June 2015) . - pp 59 - 76 Titre : GNSS-WARP software for real-time precise point positioning Type de document : Article/Communication Auteurs : Tomasz Hadas, Auteur Année de publication : 2015 Article en page(s) : pp 59 - 76 Langues : Anglais (eng) Descripteur : [Termes IGN] données GLONASS [Termes IGN] données GNSS [Termes IGN] données GPS [Termes IGN] logiciel de post-traitement GPS [Termes IGN] positionnement cinématique en temps réel [Termes IGN] positionnement ponctuel précis [Termes IGN] temps réel [Termes IGN] traitement de données GNSS [Vedettes matières IGN] Traitement de données GNSS Résumé : (auteur) On April 1, 2013 IGS launched the real-time service providing products for Precise Point Positioning (PPP). The availability of real-time makes PPP a very powerful technique to process GNSS signals in real-time and opens a new PPP applications opportunities. There are still, however, some limitations of PPP, especially in the kinematic mode. A significant change in satellite geometry is required to efficiently de-correlate troposphere delay, receiver clock offset, and receiver height. In order to challenge PPP limitations, the GNSS-WARP (Wroclaw Algorithms for Real-time Positioning) software has been developed from scratch at Wroclaw University of Environmental and Life Science in Poland. This paper presents the GNSS-WARP software itself and some results of GNSS data analysis using PPP and PPP-RTK (Real-Time Kinematic) technique. The results of static and kinematic processing in GPS only and GPS + GLONASS mode with final and real-time products are presented. Software performance validation in postprocessing mode confirmed that the software can be considered as a state-ofthe- art software and used for further studies on PPP algorithm development. The real-time positioning test made it possible to assess the quality of real-time coordinates, which is a few millimeters for North, East, Up in static mode, a below decimeter in kinematic mode. The accuracy and precision of height estimates in kinematic mode were improved by constraining the solution with an external, near real-time troposphere model. The software also allows estimation of real-time ZTD, however, the obtained precision of 11.2 mm means that further improvements in the software, real-time products or processing strategy are required. Numéro de notice : A2015-285 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/arsa-2015-0005 En ligne : https://doi.org/10.1515/arsa-2015-0005 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76403 [article]

Impact of ocean tides loading on precise point positioning based on FES2004 model / J.Z. Kalita in Artificial satellites, vol 50 n° 2 (June 2015)  

Public [article]  inArtificial satellites > vol 50 n° 2 (June 2015) . - pp 77 - 90 Titre : Impact of ocean tides loading on precise point positioning based on FES2004 model Type de document : Article/Communication Auteurs : J.Z. Kalita, Auteur ; Z. Rzepecka, Auteur Année de publication : 2015 Article en page(s) : pp 77 - 90 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement [Termes IGN] Pologne [Termes IGN] positionnement ponctuel précis [Termes IGN] surcharge océanique Résumé : (auteur) Precise Point Positioning (PPP) technique as an absolute positioning method requires modeling of effects that influence observations. One of the effects is a displacement of the measurement location due to ocean mass gravitational attraction - ocean tides loading (OTL). The model recommended by the International Earth Rotation and Reference Systems Service (IERS) is FES2004. The paper focuses on impact of applying the particular OTL model on PPP processing. The analysis is based on processing of observations from 24 globally distributed permanent stations and time span of 50 days. The analysis bases on processing intervals from 1 to 24 hours. In addition, the amplitudes of the loads in Poland are evaluated. The OTL model is location dependent, thus the importance of applying this model depends on the location environment. As the PPP is an absolute method, the loads cumulate and transfer nearly directly to the positioning solution. Consequently, for short observation intervals and small loads the application of the model does not play an important role. For the analysed station with high amplitudes of the loads the relative and absolute improvement, of the solution was the highest for height component. By applying the model, the solution improved by 19% or 7.3 mm (as for RMS and 8 hour interval). The distinct improvement for convergence exists for vertical component and threshold below 5 cm. For Poland the vertical component loads were about 5 times smaller and the highest improvement for the analysed station was 3.7% for 4 hour interval and vertical component. Numéro de notice : A2015-286 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/arsa-2015-0006 En ligne : https://doi.org/10.1515/arsa-2015-0006 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76404 [article]