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GNSS-WARP software for real-time precise point positioning / Tomasz Hadas in Artificial satellites, vol 50 n° 2 (June 2015)
[article]
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 GNSSRésumé : (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
in Artificial satellites > vol 50 n° 2 (June 2015) . - pp 59 - 76[article]Development and evaluation of GNSS/INS data processing software for position and orientation systems / X. Niu in Survey review, vol 47 n° 341 (March 2015)
[article]
Titre : Development and evaluation of GNSS/INS data processing software for position and orientation systems Type de document : Article/Communication Auteurs : X. Niu, Auteur ; Qian Zhang, Auteur ; L. Gong, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 87 - 98 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] centrale inertielle à composants liés
[Termes IGN] couplage GNSS-INS
[Termes IGN] filtre de Kalman
[Termes IGN] logiciel de post-traitement GPS
[Termes IGN] traitement de données GNSS
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) Currently there are limited supportive and reliable commercial software packages for GNSS/INS data processing. The shortage of compatible GNSS/INS data processing software has become a bottleneck in the development of position and orientation systems (POS) for survey and mapping applications. Thus this paper introduces a GNSS/INS data processing software called Cinertial, which has been recently developed in China, with open definitions of data format and parameters. The algorithm design of the software is described in detail, including the realisation of INS mechanisation, Kalman filtering, and backward smoothing. The developed software is tested and evaluated by comparing it with mainstream commercial software through processing the same field test datasets. A precise and feasible comparison procedure is proposed in the paper, so as to evaluate the quality of any new POS software in an efficient, convenient, and cost-effective way. The procedure was applied to compare our new software with two well known commercial software packages through processing airborne and terrestrial datasets respectively. The results show that the new software can achieve the same level of accuracy as the current commercial software on the market, which reflects a new progress of the POS development in China. Numéro de notice : A2015-956 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270614Y.0000000099 En ligne : http://www.tandfonline.com/doi/full/10.1179/1752270614Y.0000000099 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79941
in Survey review > vol 47 n° 341 (March 2015) . - pp 87 - 98[article]Estimation of multi-constellation GNSS observation stochastic properties using single receiver single satellite data validation method / Ahmed El-Mowafy in Survey review, vol 47 n° 341 (March 2015)
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Titre : Estimation of multi-constellation GNSS observation stochastic properties using single receiver single satellite data validation method Type de document : Article/Communication Auteurs : Ahmed El-Mowafy, Auteur Année de publication : 2015 Article en page(s) : pp 99 - 108 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] constellation GNSS
[Termes IGN] positionnement cinématique
[Termes IGN] positionnement par Galileo
[Termes IGN] positionnement par GLONASS
[Termes IGN] positionnement par GPS
[Termes IGN] positionnement statique
[Termes IGN] récepteur
[Termes IGN] validation des données
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) The single receiver single satellite validation method is a technique that screens data from each satellite independently to detect and identify faulty observations. A new method for estimation of the stochastic properties of multi-constellation GNSS observation is presented utilising parameters of this validation method. Agreement of the characteristics of the validation statistics with theory is used as the criterion to select the best precision of the observations, spectral density and correlation time of the unknowns. A curve fitting approach in an iterative scheme is employed. The method is applicable to any GNSS with any arbitrary number of frequencies. Demonstration of the method results and performance is given using multiple-frequency data from GPS, GLONASS and Galileo in static and kinematic modes. Numéro de notice : A2015-957 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270614Y.0000000100 En ligne : https://doi.org/10.1179/1752270614Y.0000000100 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79942
in Survey review > vol 47 n° 341 (March 2015) . - pp 99 - 108[article]
Titre : GPS time-variable seasonal signals modeling Type de document : Mémoire Auteurs : Qiang Chen, Auteur Editeur : Stuttgart : University of Stuttgart Année de publication : 2015 Importance : 65 p. Format : 21 x 30 cm Note générale : bibliographie
mémoire de master, Université de StuttgartLangues : Anglais (eng) Descripteur : [Termes IGN] analyse comparative
[Termes IGN] analyse de spectre singulier
[Termes IGN] compensation par moindres carrés
[Termes IGN] données GPS
[Termes IGN] filtrage du bruit
[Termes IGN] filtre de Kalman
[Termes IGN] oscillation
[Termes IGN] série temporelle
[Termes IGN] variation saisonnière
[Vedettes matières IGN] Traitement de données GNSSIndex. décimale : MX Mémoires divers Résumé : (auteur) Seasonal signals (annual plus semi-annual) in GPS time series are of great importance for understanding the evolution of regional mass, i.e. ice and hydrology. Conventionally these signals (annual and semi-annual) are derived by least-squares fitting of harmonic terms with a constant amplitude and phase. In reality, however, such seasonal signals are modulated, i.e. they will have a time-variable amplitude and phase. Recently, Davis et al. (2012) proposed a Kalman filter based approach to capture the stochastic seasonal behavior of geodetic time series. In this study, a non-parametric approach, singular spectrum analysis (SSA) is introduced. It uses time domain data to extract information from short and noisy time series without prior knowledge of the dynamics affecting the time series. A prominent benefit is that obtained trends are not necessarily linear and extracted oscillations can be amplitude and phase modulated. In this work, the capability of SSA for analyzing time-variable seasonal signals from GPS time series is investigated. We also compare SSA-based results to two model-based results, i.e. least-squares analysis and Kalman filtering. Our results show that singular spectrum analysis could be a viable and complementary tool for exploring modulated oscillations from GPS time series. Based on the SSA-derived seasonal signals, we look into the effects of the input noise variances in the framework of Kalman filtering. Two Kalman filtering based approaches with different process noise models are compared over 79 GPS sites. We find that the basic Kalman filtering technique with the input noise model suggested by Davis et al. (2012) turns out to be optimal. Numéro de notice : 17348 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Mémoire masters divers En ligne : http://dx.doi.org/10.18419/opus-8824 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83707 Validity and behaviour of tropospheric gradients estimated by GPS in Corsica / Laurent Morel in Advances in space research, vol 55 n° 1 ([01/01/2015])
[article]
Titre : Validity and behaviour of tropospheric gradients estimated by GPS in Corsica Type de document : Article/Communication Auteurs : Laurent Morel, Auteur ; Eric Pottiaux, Auteur ; Frédéric Durand, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 135 - 149 Langues : Anglais (eng) Descripteur : [Termes IGN] Corse
[Termes IGN] GAMIT
[Termes IGN] GIPSY-OASIS
[Termes IGN] gradient de troposphère
[Termes IGN] retard troposphérique
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) Estimation of tropospheric gradients in GNSS data processing is a well-known technique to improve positioning (e.g. Bar-Sever et al., 1998; Chen and Herring, 1997). More recently, several authors also focused on the estimation of such parameters for meteorological studies and demonstrated their potential benefits (e.g. Champollion et al., 2004). Today, they are routinely estimated by several global and regional GNSS analysis centres but they are still not yet used for operational meteorology.
This paper discusses the physical meaning of tropospheric gradients estimated from GPS observations recorded in 2011 by 13 permanent stations located in Corsica Island (a French Island in the western part of Italy). Corsica Island is a particularly interesting location for such study as it presents a significant environmental contrast between the continent and the sea, as well as a steep topography.
Therefore, we estimated Zenith Total Delay (ZTD) and tropospheric gradients using two software: GAMIT/GLOBK (GAMIT version 10.5) and GIPSY-OASIS II version 6.1. Our results are then compared to radiosonde observations and to the IGS final troposphere products. For all stations we found a good agreement between the ZWD estimated by the two software (the mean of the ZWD differences is 1 mm with a standard deviation of 6 mm) but the tropospheric gradients are in less good agreement (the mean of the gradient differences is 0.1 mm with a standard deviation of 0.7 mm), despite the differences in the processing strategy (double-differences for GAMIT/GLOBK versus zero-difference for GIPSY-OASIS).
We also observe that gradient amplitudes are correlated with the seasonal behaviour of the humidity. Like ZWD estimates, they are larger in summer than in winter. Their directions are stable over the time but not correlated with the IWV anomaly observed by ERA-Interim. Tropospheric gradients observed at many sites always point to inland throughout the year. These preferred directions are almost opposite to the largest slope of the local topography as derived from the world Digital Elevation Model ASTER GDEM v2. These first results give a physical meaning to gradients but the origin of such directions need further investigations.Numéro de notice : A2015-297 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2014.10.004 En ligne : https://doi.org/10.1016/j.asr.2014.10.004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76458
in Advances in space research > vol 55 n° 1 [01/01/2015] . - pp 135 - 149[article]GNSS ambiguity resolution with controllable failure rate for long baseline network RTK / Bofeng Li in Journal of geodesy, vol 88 n° 2 (February 2014)PermalinkPermalinkApprendre le positionnement par GNSS avec le logiciel RTKLIB / Pierre Bosser (2014)PermalinkHomogénéisation des séries temporelles GPS par la méthode de la segmentation / François Guillamon (2014)PermalinkPermalinkModélisation de la propagation troposphérique des signaux de positionnement par satellites : un tour d'horizon / Camille Desjardins (2014)PermalinkSingular spectrum analysis for modeling seasonal signals from GPS time series / Q. Chen in Journal of geodynamics, vol 72 (December 2013)PermalinkSubseasonal GNSS positioning errors / Jim Ray in Geophysical research letters, vol 40 n° 22 (November 2013)PermalinkPermalinkCorrelated errors in GPS position time series: Implications for velocity estimates / Alvaro Santamaria Gomez in Journal of geophysical research : Solid Earth, Vol 116 n° B1 (January 2011)Permalink