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Irregular variations in GPS time series by probability and noise analysis / Anna Klos in Survey review, vol 47 n° 342 (May 2015)  

Public [article]  inSurvey review > vol 47 n° 342 (May 2015) . - pp 163 - 173 Titre : Irregular variations in GPS time series by probability and noise analysis Type de document : Article/Communication Auteurs : Anna Klos, Auteur ; Janusz Bogusz, Auteur ; Mariusz Figurski, Auteur ; Wieslaw Kosek, Auteur Année de publication : 2015 Article en page(s) : pp 163 - 173 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal [Termes IGN] bruit (théorie du signal) [Termes IGN] bruit blanc [Termes IGN] bruit rose [Termes IGN] classification par maximum de vraisemblance [Termes IGN] écart type [Termes IGN] filtrage du bruit [Termes IGN] métrique [Termes IGN] récepteur GPS [Termes IGN] série temporelle Résumé : (auteur) The character of the topocentric components in ETRF2000(R08) from the Polish ASG-EUPOS system was analysed using skewness and kurtosis derived from the data probability density function. The data from 115 permanent GPS stations with a time span of more than 5 years were used. The main goal of this research was to show that any unmodelled systematics can disrupt the results. The obtained median values of skewness and kurtosis clearly indicate the discrepancies between the assumed normality of the GPS time series distribution and the reality, mainly due to stochastic and/or deterministic parts that are still present in the data. The quadratic relationship between skewness and kurtosis was developed with the empirically determined constants. The noise analysis with the Maximum Likelihood Estimation was also performed with the assumptions of white and white plus power-law noise. The estimated spectral indices for power law noises are close to −1 (flicker noise). The uncertainties of the intraplate velocities with white and white plus power law noise assumptions were calculated. It was shown that these uncertainties can be underestimated up to 5 mm/year. Additionally we made 1000 simulation which were aimed at showing how the values of skewness and kurtosis are changed when some mismodelled part of the data remains in the time series. We assumed different values of trend (1 and 6 mm/year), seasonal amplitudes (1 and 6 mm) and offsets (3 and 10 mm) with flicker noise of 1 mm amplitude to see how the metrics we use are biased. Numéro de notice : A2015-930 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270614Y.0000000133 En ligne : https://doi.org/10.1179/1752270614Y.0000000133 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79735 [article]

Spatio-temporal filtering for determination of common mode error in regional GNSS networks / Janusz Bogusz in Open geosciences, vol 7 n° 1 (January 2015)  

Public [article]  inOpen geosciences > vol 7 n° 1 (January 2015) . - pp 140 - 148 Titre : Spatio-temporal filtering for determination of common mode error in regional GNSS networks Type de document : Article/Communication Auteurs : Janusz Bogusz, Auteur ; Maciej Gruszczynski, Auteur ; Mariusz Figurski, Auteur ; Anna Klos, Auteur Année de publication : 2015 Article en page(s) : pp 140 - 148 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux [Termes IGN] erreur de positionnement [Termes IGN] EUPOS [Termes IGN] filtrage spatiotemporel [Termes IGN] Pologne [Termes IGN] positionnement par GNSS [Termes IGN] série temporelle Résumé : (auteur) The spatial correlation between different stations for individual components in the regional GNSS networks seems to be significant. The mismodelling in satellite orbits, the Earth orientation parameters (EOP), largescale atmospheric effects or satellite antenna phase centre corrections can all cause the regionally correlated errors. This kind of GPS time series errors are referred to as common mode errors (CMEs). They are usually estimated with the regional spatial filtering, such as the "stacking". In this paper, we show the stacking approach for the set of ASG-EUPOS permanent stations, assuming that spatial distribution of the CME is uniform over the whole region of Poland (more than 600 km extent). The ASG-EUPOS is a multifunctional precise positioning system based on the reference network designed for Poland. We used a 5- year span time series (2008-2012) of daily solutions in the ITRF2008 from Bernese 5.0 processed by the Military University of Technology EPN Local Analysis Centre (MUT LAC). At the beginning of our analyses concerning spatial dependencies, the correlation coefficients between each pair of the stations in the GNSS network were calculated. This analysis shows that spatio-temporal behaviour of the GPS-derived time series is not purely random, but there is the evident uniform spatial response. In order to quantify the influence of filtering using CME, the norms L1 and L2 were determined. The values of these norms were calculated for the North, East and Up components twice: before performing the filtration and after stacking. The observed reduction of the L1 and L2 norms was up to 30% depending on the dimension of the network. However, the question how to define an optimal size of CME-analysed subnetwork remains unanswered in this research, due to the fact that our network is not extended enough. Numéro de notice : A2015-439 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/geo-2015-0021 En ligne : https://doi.org/10.1515/geo-2015-0021 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77039 [article]

Homogeneous zenith total delay parameter estimation from European permanent GNSS sites / Wolfgang Söhne in Bulletin of geodesy and geomatics BGG, vol 69 n° 1 (March 2010)

Public [article]  inBulletin of geodesy and geomatics BGG > vol 69 n° 1 (March 2010) . - pp 11 - 20 Titre : Homogeneous zenith total delay parameter estimation from European permanent GNSS sites Type de document : Article/Communication Auteurs : Wolfgang Söhne, Auteur ; Mariusz Figurski, Auteur ; K. Szafranek, Auteur Année de publication : 2010 Article en page(s) : pp 11 - 20 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] estimation statistique [Termes IGN] propagation troposphérique [Termes IGN] réseau permanent EUREF [Termes IGN] rotation de la Terre [Termes IGN] station GNSS [Termes IGN] traitement de données GNSS Résumé : (Auteur) Starting in 2001 the EUREF Permanent Network (EPN) Local Analysis Centres (LAC) are delivering Zenith Total Delay (ZTD) parameters which were combined at the BKG (Bundesamt für Kartographie und Geodäsie, Germany) combination facility. The results have been step-by-step improved, depending on several changes of the processing scheme, leading to an internal precision of 2-3 mm ZTD. The availability of a set of homogeneously processed GPS satellite orbits, clocks and Earth Rotation Parameters (ERP) covering a period of more than a decade (the so-called Potsdam-Dresden reprocessing) motivated MUT (Military University of Technology, Poland) to the all-in-one processing of the EPN stations for the same period. The applied strategy thereby followed the guidelines for EPN processing. While the improvement in coordinate estimation has been recently demonstrated, this paper investigates the quality of the ZTD parameters estimated together with the coordinates. Comparisons with the existing EUREF combined solution, with IGS solutions and with radiosonde data will be presented to evaluate the possible improvement in ZTD estimation by reprocessing activities. Numéro de notice : A2010-588 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77986 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
013-2010011	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Homogeneous reprocessing of the EUREF permanent network : first experiences and comparisons / A. Kenyeres in Bulletin of geodesy and geomatics BGG, vol 68 n° 3 (October 2009)

Public [article]  inBulletin of geodesy and geomatics BGG > vol 68 n° 3 (October 2009) . - pp 207 - 218 Titre : Homogeneous reprocessing of the EUREF permanent network : first experiences and comparisons Type de document : Article/Communication Auteurs : A. Kenyeres, Auteur ; Mariusz Figurski, Auteur ; P. Kaminski, Auteur ; et al., Auteur Année de publication : 2009 Article en page(s) : pp 207 - 218 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux [Termes IGN] CATREF [Termes IGN] centre de phase [Termes IGN] données géodésiques [Termes IGN] réseau géodésique permanent [Termes IGN] réseau permanent EUREF [Termes IGN] série temporelle [Termes IGN] traitement de données GNSS Résumé : (Auteur) The GPS analysis strategies, the applied models and software have been considerably changed since the global (IGS - International GNSS Service) and regional (EPN - EUREF Permanent Network) CORS networks are operational. All changes brought along temporal inhomogeneities in the estimated parameters, most apparently in the coordinate time series. After the introduction of the absolute phase centre variation (PCV) models of the satellite and ground GPS antennae, the complete re-analysis of the historical measurements could not be postponed. Within the IGS the re-analysis is now in progress and it will be followed by a coordinated re-processing of the EPN observations from 1996 on. In preparation of the EPN reprocessing a pilot re-analysis has been done at the Military University of Technology (MUT) in Poland covering the complete EPN dataset and similar work has been started at the Royal Observatory of Belgium (ROB). The target of this work was to assess the required resources, the status and completeness of the database and to quantify the improvement gained by the reprocessing. Using the CATREF software (Altamimi et al. 2004) two cumulative solutions have been created by stacking the standard and the reprocessed weekly EPN SINEX solutions. In this paper, the first analysis of the estimated coordinates, velocities and the residual time series is presented. We detected 10-30% improvement in the weekly weighted RMS, we got smoother time series with smaller coordinate repeatability and a more «ITRF2005-conform» velocity field. The results highly support the need for a complete (from global to local level) GPS reprocessing and the establishment of a new ITRS realization in agreement with the GPS absolute PCV models. Numéro de notice : A2009-566 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77993 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
013-09031	RAB	Revue	Centre de documentation	En réserve L003	Disponible