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A new method for specular and diffuse pseudorange multipath error extraction using wavelet analysis / Giovanni Pugliano in GPS solutions, vol 20 n° 3 (July 2016)
[article]
Titre : A new method for specular and diffuse pseudorange multipath error extraction using wavelet analysis Type de document : Article/Communication Auteurs : Giovanni Pugliano, Auteur ; Umberto Robustelli, Auteur ; Fabio Rossi, Auteur ; Raffaele Santamaria, Auteur Année de publication : 2016 Article en page(s) : pp 499 - 508 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Campanie (Italie)
[Termes IGN] correction du trajet multiple
[Termes IGN] mesurage de pseudo-distance
[Termes IGN] onde porteuse
[Termes IGN] réflexion spéculaire
[Termes IGN] transformation en ondelettes
[Vedettes matières IGN] Traitement de données GNSSRésumé : (Auteur) Multipath remains one of the major challenges in Global Navigation Satellite System (GNSS) positioning because it is considered the dominant source of ranging errors, which can be classified into specular and diffuse types. We present a new method using wavelets to extract the pseudorange multipath in the time domain and breaking it down into the two components. The main idea is an analysis-reconstruction approach based on application of both continuous wavelet transform (CWT) and discrete wavelet transform (DWT). The proposed procedure involves the use of L1 code-minus-carrier (CMC) observable where higher-frequency terms are isolated as residuals. CMC residuals are analyzed by applying the CWT, and we propose the scalogram as a technique for discerning time–frequency variations of the multipath signal. Unlike Fourier transform, the potential of the CWT scalogram for examining the non-stationary and multifrequency nature of the multipath is confirmed as it simultaneously allows fine detection and time localization of the most representative frequencies of the signal. This interpretation of the CWT scalogram is relevant when choosing the levels of reconstruction with DWT, allowing accurate time domain extraction of both the specular and diffuse multipath. The performance and robustness of the method and its boundary applicability are assessed. The experiment was carried out using a receiver of Campania GNSS Network. The results are given in which specular multipath error is achieved using DWT level 7 approximation component and diffuse multipath error is achieved using DWT level 6 denoised detail component. Numéro de notice : A2016-634 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-015-0458-0 En ligne : http://dx.doi.org/10.1007/s10291-015-0458-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81838
in GPS solutions > vol 20 n° 3 (July 2016) . - pp 499 - 508[article]Improving the quality of low-cost GPS receiver data for monitoring using spatial correlations / Li Zhang in Journal of applied geodesy, vol 10 n° 2 (June 2016)
[article]
Titre : Improving the quality of low-cost GPS receiver data for monitoring using spatial correlations Type de document : Article/Communication Auteurs : Li Zhang, Auteur ; Volker Schwieger, Auteur Année de publication : 2016 Article en page(s) : pp 119 - 129 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] correction du trajet multiple
[Termes IGN] corrélation automatique de points homologues
[Termes IGN] coût
[Termes IGN] récepteur GPS
[Termes IGN] récepteur monofréquence
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) The investigations on low-cost single frequency GPS receivers at the Institute of Engineering Geodesy (IIGS) show that u-blox LEA-6T GPS receivers combined with Trimble Bullet III GPS antennas containing self-constructed L1-optimized choke rings can already obtain an accuracy in the range of millimeters which meets the requirements of geodetic precise monitoring applications (see [27]). However, the quality (accuracy and reliability) of low-cost GPS receiver data, particularly in shadowing environment, should still be improved, since the multipath effects are the major error for the short baselines.
For this purpose, several adjoined stations with low-cost GPS receivers and antennas were set up next to the metal wall on the roof of the IIGS building and measured statically for several days. The time series of three-dimensional coordinates of the GPS receivers were analyzed. Spatial correlations between the adjoined stations, possibly caused by multipath effect, will be taken into account. The coordinates of one station can be corrected using the spatial correlations of the adjoined stations, so that the quality of the GPS measurements is improved.
The developed algorithms are based on the coordinates and the results will be delivered in near-real-time (in about 30 minutes), so that they are suitable for structural health monitoring applications.Numéro de notice : A2016-559 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2015-0022 En ligne : http://dx.doi.org/10.1515/jag-2015-0022 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81738
in Journal of applied geodesy > vol 10 n° 2 (June 2016) . - pp 119 - 129[article]Rapid mapping method based on free blocks of surveys / Xianwen Yu in Journal of applied geodesy, vol 10 n° 2 (June 2016)
[article]
Titre : Rapid mapping method based on free blocks of surveys Type de document : Article/Communication Auteurs : Xianwen Yu, Auteur ; Huiqing Wang, Auteur ; Jinling Wang, Auteur Année de publication : 2016 Article en page(s) : pp 131 - 138 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] coordonnées GPS
[Termes IGN] matrice de covariance
[Termes IGN] transformation de coordonnées
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) While producing large-scale larger than 1:2000 maps in cities or towns, the obstruction from buildings leads to difficult and heavy tasks of measuring mapping control points. In order to avoid measuring the mapping control points and shorten the time of fieldwork, in this paper, a quick mapping method is proposed. This method adjusts many free blocks of surveys together, and transforms the points from all free blocks of surveys into the same coordinate system. The entire surveying area is divided into many free blocks, and connection points are set on the boundaries between free blocks. An independent coordinate system of every free block is established via completely free station technology, and the coordinates of the connection points, detail points and control points in every free block in the corresponding independent coordinate systems are obtained based on poly-directional open traverses. Error equations are established based on connection points, which are determined together to obtain the transformation parameters. All points are transformed from the independent coordinate systems to a transitional coordinate system via the transformation parameters. Several control points are then measured by GPS in a geodetic coordinate system. All the points can then be transformed from the transitional coordinate system to the geodetic coordinate system. In this paper, the implementation process and mathematical formulas of the new method are presented in detail, and the formula to estimate the precision of surveys is given. An example has demonstrated that the precision of using the new method could meet large-scale mapping needs. Numéro de notice : A2016-560 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2015-0034 En ligne : https://doi.org/10.1515/jag-2015-0034 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81739
in Journal of applied geodesy > vol 10 n° 2 (June 2016) . - pp 131 - 138[article]An effective toolkit for the interpolation and gross error detection of GPS time series / X. Wang in Survey review, vol 48 n° 348 (May 2016)
[article]
Titre : An effective toolkit for the interpolation and gross error detection of GPS time series Type de document : Article/Communication Auteurs : X. Wang, Auteur ; Y. Cheng, Auteur ; S. Wu, Auteur ; K. Zhang, Auteur Année de publication : 2016 Article en page(s) : pp 202 - 211 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse de spectre singulier
[Termes IGN] coordonnées GPS
[Termes IGN] détection d'erreur
[Termes IGN] interpolation
[Termes IGN] modèle de simulation
[Termes IGN] série temporelle
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) As data gaps and gross errors inevitably exist in GPS time series, robust detection and interpolation procedures are needed to obtain a uniform time series for various geospatial studies and applications. The use of traditional methods for this purpose is usually based on some improper assumptions, which are not derived based on the real properties of the data. Moreover, different interpolation methods may need to be investigated for interpolation for various gaps with different types and amount of missing data. These make the interpolation for missing data not easy. To address the issue of mentioned above, in this study, a data-analysis method named singular spectrum analysis (SSA) for missing data is assessed for reconstructing a reliable model from unevenly sampled time series without the need for any a priori knowledge of the time series data. In this method, the interpolation and detection of gross errors are carried out in one go along with the reliable reconstructed model. Both simulation data and real GPS data testing results showed that this was an efficient method for interpolation and gross error detection. Numéro de notice : A2016-276 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270615Y.0000000023 En ligne : http://doi.org/10.1179/1752270615Y.0000000023 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80830
in Survey review > vol 48 n° 348 (May 2016) . - pp 202 - 211[article]Towards reliable velocities of permanent GNSS stations / Janusz Bogusz in Reports on geodesy and geoinformatics, vol 100 (May 2016)
[article]
Titre : Towards reliable velocities of permanent GNSS stations Type de document : Article/Communication Auteurs : Janusz Bogusz, Auteur ; Anna Klos, Auteur ; Marta Gruszczynska, Auteur ; Maciej Gruszczynski, Auteur Année de publication : 2016 Article en page(s) : pp 17 - 26 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse de spectre singulier
[Termes IGN] analyse en composantes principales
[Termes IGN] bruit (théorie du signal)
[Termes IGN] coordonnées GNSS
[Termes IGN] série temporelle
[Termes IGN] station permanente
[Termes IGN] vitesse
[Vedettes matières IGN] Traitement de données GNSSRésumé : (Auteur) In the modern geodesy the role of the permanent station is growing constantly. The proper treatment of the time series from such station lead to the determination of the reliable velocities. In this paper we focused on some pre-analysis as well as analysis issues, which have to be performed upon the time series of the North, East and Up components and showed the best, in our opinion, methods of determination of periodicities (by means of Singular Spectrum Analysis) and spatio-temporal correlations (Principal Component Analysis), that still exist in the time series despite modelling. Finally, the velocities of the selected European permanent stations with the associated errors determined following power-law assumption in the stochastic part is presented.
In this paper we preliminary discuss methods for collecting raster data in a geodatabase by processing open multi-temporal and multi-scale satellite data aimed at retrieving indicators for land degradation phenomenon (i.e. land cover/land use analysis, vegetation indices, trend analysis, etc.). Then we describe a methodology for designing a WebGIS framework in order to disseminate information through maps for territory monitoring. Basic WebGIS functions were extended with the help of POSTGIS database and OpenLayers libraries. Geoserver was customized to set up and enhance the website functions developing various advanced queries using PostgreSQL and innovative tools to carry out efficiently multi-layer overlay analysis. The end-product is a simple system that provides the opportunity not only to consult interactively but also download processed remote sensing data.Numéro de notice : A2016-645 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/rgg-2016-0003 En ligne : http://dx.doi.org/10.1515/rgg-2016-0003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81851
in Reports on geodesy and geoinformatics > vol 100 (May 2016) . - pp 17 - 26[article]Comparative analysis of real-time precise point positioning zenith total delay estimates / F.A. Ahmed in GPS solutions, vol 20 n° 2 (April 2016)PermalinkImpact of the arc length on GNSS analysis results / Simon Lutz in Journal of geodesy, vol 90 n° 4 (April 2016)PermalinkA study on the dependency of GNSS pseudorange biases on correlator spacing / André Hauschild in GPS solutions, vol 20 n° 2 (April 2016)Permalink14 years of GPS tropospheric delays in the French–Italian border region : comparisons and first application in a case study / Domenico Sguerso in Applied geomatics, vol 8 n° 1 (March 2016)PermalinkDetermination of differential code biases with multi-GNSS observations / Ningbo Wang in Journal of geodesy, vol 90 n° 3 (March 2016)PermalinkInvestigations on the influence of antenna near-field effects and satellite obstruction on the uncertainty of GNSS-based distance measurements / Florian Zimmermann in Journal of applied geodesy, vol 10 n° 1 (March 2016)PermalinkPotential of GPS common clock single-differences for deformation monitoring / Steffen Schön in Journal of applied geodesy, vol 10 n° 1 (March 2016)PermalinkThe study of seasonal changes of permanent stations coordinates based on weekly EPN solutions / Kamil Maciuk in Artificial satellites, vol 51 n° 1 (March 2016)PermalinkTime series analysis of 3D coordinates using nonstochastic observations / Hiddo Velsink in Journal of applied geodesy, vol 10 n° 1 (March 2016)PermalinkPermalinkEffectiveness of observation-domain sidereal filtering for GPS precise point positioning / Christopher Atkins in GPS solutions, vol 20 n° 1 (January 2016)PermalinkTight integration of ambiguity-fixed PPP and INS: model description and initial results / Shuai Liu in GPS solutions, vol 20 n° 1 (January 2016)PermalinkWide-area ionospheric delay model for GNSS users in middle- and low-magnetic-latitude regions / An-Lin Tao in GPS solutions, vol 20 n° 1 (January 2016)PermalinkParticle filter-based estimation of inter-frequency phase bias for real-time GLONASS integer ambiguity resolution / Yumiao Tian in Journal of geodesy, vol 89 n° 11 (november 2015)PermalinkBeiDou phase bias estimation and its application in precise point positioning with triple-frequency observable / Shengfeng Gu in Journal of geodesy, vol 89 n° 10 (october 2015)PermalinkNew data processing strategy for single frequency GPS deformation monitoring / S-Q. Huang in Survey review, vol 47 n° 344 (September 2015)PermalinkImpacts of real-time satellite clock errors on GPS precise point positioning-based troposphere zenith delay estimation / Junbo Shi in Journal of geodesy, vol 89 n° 8 (August 2015)PermalinkSingle-frequency precise point positioning: an analytical approach / Oskar Sterle in Journal of geodesy, vol 89 n° 8 (August 2015)PermalinkA worldwide ionospheric model for fast precise point positioning / Adria Rovira-Garcia in IEEE Transactions on geoscience and remote sensing, vol 53 n° 8 (August 2015)PermalinkAn improved between-satellite single-difference precise point positioning model for combined GPS/Galileo observations / Akram Afifi in Journal of applied geodesy, vol 9 n° 2 (June 2015)PermalinkGNSS-WARP software for real-time precise point positioning / Tomasz Hadas in Artificial satellites, vol 50 n° 2 (June 2015)PermalinkDevelopment and evaluation of GNSS/INS data processing software for position and orientation systems / X. Niu in Survey review, vol 47 n° 341 (March 2015)PermalinkEstimation 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)PermalinkPermalinkValidity and behaviour of tropospheric gradients estimated by GPS in Corsica / Laurent Morel in Advances in space research, vol 55 n° 1 ([01/01/2015])PermalinkGNSS 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)PermalinkL'allongement troposphérique / Samuel Nahmani (2008)PermalinkAn Improved mean-gravity model for GPS hydrostatic delay calibration / Pierre Bosser in IEEE Geoscience and Remote Sensing Letters, vol 4 n° 1 (2007)Permalink