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Reflected blessings : position estimation using non-line-of-sight GPS signals / Yuting Ng in GPS world, vol 28 n° 3 (March 2017)
[article]
Titre : Reflected blessings : position estimation using non-line-of-sight GPS signals Type de document : Article/Communication Auteurs : Yuting Ng, Auteur ; Grace Xingxin Gao, Auteur Année de publication : 2017 Article en page(s) : pp 42 - 47 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] estimation de position
[Termes IGN] signal GPS
[Termes IGN] trajet multipleRésumé : (Auteur) Building obstructions and reflections present serious challenges to GPS receivers operating in urban environments. In such environments, buildings may obstruct GPS signals, leading to reduced GPS signal availability. In addition, buildings may reflect GPS signals, resulting in reception of nonline- of-sight (NLOS) signals. NLOS GPS signals are delayed versions of the line-of-sight (LOS) signals. As such, they lead to pseudorange errors, resulting in positioning errors. Conventional approaches treat NLOS GPS signals as unwanted interference to be rejected or mitigated. Numéro de notice : A2017-291 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85326
in GPS world > vol 28 n° 3 (March 2017) . - pp 42 - 47[article]A drift line bias estimator: ARMA-based filter or calibration method, and its application in BDS/GPS-based attitude determination / Zhang Liang in Journal of geodesy, vol 90 n° 12 (December 2016)
[article]
Titre : A drift line bias estimator: ARMA-based filter or calibration method, and its application in BDS/GPS-based attitude determination Type de document : Article/Communication Auteurs : Zhang Liang, Auteur ; Hou Yanqing, Auteur ; Wu Jie, Auteur Année de publication : 2016 Article en page(s) : pp 1331 - 1343 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] échantillonnage de signal
[Termes IGN] erreur systématique
[Termes IGN] estimateur
[Termes IGN] étalonnage des données
[Termes IGN] filtrage du signal
[Termes IGN] positionnement ponctuel précis
[Termes IGN] signal BeiDou
[Termes IGN] signal GPSRésumé : (Auteur) The multi-antenna synchronized receiver (using a common clock) is widely applied in GNSS-based attitude determination (AD) or terrain deformations monitoring, and many other applications, since the high-accuracy single-differenced carrier phase can be used to improve the positioning or AD accuracy. Thus, the line bias (LB) parameter (fractional bias isolating) should be calibrated in the single-differenced phase equations. In the past decades, all researchers estimated the LB as a constant parameter in advance and compensated it in real time. However, the constant LB assumption is inappropriate in practical applications because of the physical length and permittivity changes of the cables, caused by the environmental temperature variation and the instability of receiver-self inner circuit transmitting delay. Considering the LB drift (or colored LB) in practical circumstances, this paper initiates a real-time estimator using auto regressive moving average-based (ARMA) prediction/whitening filter model or Moving average-based (MA) constant calibration model. In the ARMA-based filter model, four cases namely AR(1), ARMA(1, 1), AR(2) and ARMA(2, 1) are applied for the LB prediction. The real-time relative positioning model using the ARMA-based predicting LB is derived and it is theoretically proved that the positioning accuracy is better than the traditional double difference carrier phase (DDCP) model. The drifting LB is defined with a phase temperature changing rate integral function, which is a random walk process if the phase temperature changing rate is white noise, and is validated by the analysis of the AR model coefficient. The auto covariance function shows that the LB is indeed varying in time and estimating it as a constant is not safe, which is also demonstrated by the analysis on LB variation of each visible satellite during a zero and short baseline BDS/GPS experiment. Compared to the DDCP approach, in the zero-baseline experiment, the LB constant calibration (LBCC) and MA approaches improved the positioning accuracy of the vertical component, while slightly degrading the accuracy of the horizontal components. The ARMA(1, 0) model, however, improved the positioning accuracy of all three components, with 40 and 50 % improvement of the vertical component for BDS and GPS, respectively. In the short baseline experiment, compared to the DDCP approach, the LBCC approach yielded bad positioning solutions and degraded the AD accuracy; both MA and ARMA-based filter approaches improved the AD accuracy. Moreover, the ARMA(1, 0) and ARMA(1, 1) models have relatively better performance, improving to 55 % and 48 % the elevation angle in ARMA(1, 1) and MA model for GPS, respectively. Furthermore, the drifting LB variation is found to be continuous and slowly cumulative; the variation magnitudes in the unit of length are almost identical on different frequency carrier phases, so the LB variation does not show obvious correlation between different frequencies. Consequently, the wide-lane LB in the unit of cycle is very stable, while the narrow-lane LB varies largely in time. This reasoning probably also explains the phenomenon that the wide-lane LB originating in the satellites is stable, while the narrow-lane LB varies. The results of ARMA-based filters are better than the MA model, which probably implies that the modeling for drifting LB can further improve the precise point positioning accuracy. Numéro de notice : A2016-805 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0926-5 En ligne : http://dx.doi.org/10.1007/s00190-016-0926-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82593
in Journal of geodesy > vol 90 n° 12 (December 2016) . - pp 1331 - 1343[article]Monitoring and prediction of precipitable water vapor using GPS data in Turkey / Kutubuddin Ansari in Journal of applied geodesy, vol 10 n° 4 (December 2016)
[article]
Titre : Monitoring and prediction of precipitable water vapor using GPS data in Turkey Type de document : Article/Communication Auteurs : Kutubuddin Ansari, Auteur ; Omar F. Althuwaynee, Auteur ; Ozsen Corumluoglu, Auteur Année de publication : 2016 Article en page(s) : pp 233 – 245 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] analyse diachronique
[Termes IGN] données météorologiques
[Termes IGN] effet atmosphérique
[Termes IGN] précipitation
[Termes IGN] réfraction atmosphérique
[Termes IGN] réseau géodésique permanent
[Termes IGN] signal GPS
[Termes IGN] température
[Termes IGN] Turquie
[Termes IGN] vapeur d'eauRésumé : (auteur) Although Global Positioning System (GPS) primarily provide accurate estimates of position, velocity and time of the receiver, as the signals pass through the atmoshphere carrying its signatures, thus offers opportunities for atmoshpheric applications. Precipitable water vapor (PWV) is a vital component of the atmosphere and significantly influences atmospheric processes like rainfall and atmospheric temperature. The developing networks of continuously operating GPS can be used to efficiently estimate PWV. The Turkish Permanent GPS Network (TPGN) is employed to monitor PWV information in Turkey. This work primarily aims to derive long-term data of PWV by using atmospheric path delays observed through continuously operating TPGN from November 2014 to October 2015. A least square mathematical approach was then applied to establish the relation of the observed PWV to rainfall and temperature. The modeled PWV was correlated with PWV estimated from GPS data, with an average correlation of 67.10 %–88.60 %. The estimated root mean square error (RMSE) varied from 2.840 to 6.380, with an average of 4.697. Finally, data of TPGN, rainfall, and temperature were obtained for less than 2 months (November 2015 to December 2015) and assessed to validate the mathematical model. This study provides a basis for determining PWV by using rainfall and temperature data. Numéro de notice : A206-973 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2016-0037 En ligne : https://doi.org/10.1515/jag-2016-0037 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83680
in Journal of applied geodesy > vol 10 n° 4 (December 2016) . - pp 233 – 245[article]Variations of total electron content over Serbia during the increased solar activity period in 2013 and 2014 / Dragan Blagojevic in Geodetski vestnik, vol 60 n° 4 (December 2016)
[article]
Titre : Variations of total electron content over Serbia during the increased solar activity period in 2013 and 2014 Type de document : Article/Communication Auteurs : Dragan Blagojevic, Auteur ; Miljana Todorović Drakul, Auteur ; Oleg Odalovic, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 734 - 744 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse diachronique
[Termes IGN] propagation du signal
[Termes IGN] propagation ionosphérique
[Termes IGN] retard ionosphèrique
[Termes IGN] Serbie
[Termes IGN] signal GPS
[Termes IGN] teneur totale en électrons
[Termes IGN] verticaleRésumé : (auteur) To understand general ionosphere properties over Serbia, an analysis of temporal and spatial ionosphere Total Electron Content (TEC) over the region was performed. The present research focuses on daily, seasonal and spatial ionosphere variations, based on TEC series calculated from the GNSS ie. GPS measurements. This analysis provides for characterization of ionosphere nature and fine structure over Serbia, both locally and regionally. For the days with high solar activity changes of TEC values ranges from minimum 4 Total Electron Content Units (TECU), in night hours, up to 55 TECU around the noon. It is shown that that changes are equivalent to the delay of GPS signals approximately 8.8 m in vertical direction during the (maximum) daily conditions and the delay of 0.6 m during the (minimum) night conditions. Also, it is shows that a seasonal TEC differences follows directly Sun activity during the seasons, and maximal differences of TEC values between the seasons reaching values of 45 TECU, again in the years of high Sun’s activities. For spatial changes all gained results indicate that there exist changes in all directions which cannot be recognized as constant bias or a trend. Numéro de notice : A2016-968 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.15292/geodetski-vestnik.2016.04.734-744 En ligne : http://dx.doi.org/10.15292/geodetski-vestnik.2016.04.734-744 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83673
in Geodetski vestnik > vol 60 n° 4 (December 2016) . - pp 734 - 744[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 139-2016041 RAB Revue Centre de documentation En réserve L003 Disponible On the significance of periodic signals in noise analysis of GPS station coordinates time series / Janusz Bogusz in GPS solutions, vol 20 n° 4 (October 2016)
[article]
Titre : On the significance of periodic signals in noise analysis of GPS station coordinates time series Type de document : Article/Communication Auteurs : Janusz Bogusz, Auteur ; Anna Klos, Auteur Année de publication : 2016 Article en page(s) : pp 655 - 664 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] analyse diachronique
[Termes IGN] bruit (théorie du signal)
[Termes IGN] coordonnées cartésiennes géocentriques
[Termes IGN] GIPSY-OASIS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] série temporelle
[Termes IGN] signal GPS
[Termes IGN] station GPS
[Termes IGN] variation saisonnière
[Termes IGN] vitesseRésumé : (Auteur) Each of the GPS-derived time series consists of the deterministic (functional) and stochastic part. We propose that the deterministic part includes all periodicities from 1st to 9th harmonics of residual Chandler, tropical and draconitic periods and compare it with commonly used calculations of the annual and semi-annual tropical curve. Then, we address the issues of whether all residual periodicities, as proposed here, need to be taken into consideration when performing noise analysis. We use the position time series from 180 International GNSS Service stations obtained at the Jet Propulsion Laboratory using the GIPSY-OASIS software in a Precise Point Positioning mode. The longest series has 22.1 years of GPS daily solutions. The spectral indices range from –0.12 to –0.92, while the median values of “global” spectral indices are equal to: –0.41 ± 0.15, –0.38 ± 0.12 and –0.33 ± 0.18 for North, East and Up components, respectively. All non-modelled geophysical processes or non-included artificial effects in time series lead to an underestimation of errors of velocities, but also to changes in the velocity values themselves. The proposed assumption of seasonals subtraction caused the Akaike information criterion values to show a decrease in the median value of 30 %, which in fact means that all the seasonals mentioned here must be taken into account when analyzing noises. Finally, we noticed that there are some of the GPS stations that improved their velocity uncertainty even of 56 %. Numéro de notice : A2016--027 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-015-0478-9 En ligne : http://dx.doi.org/10.1007/s10291-015-0478-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83929
in GPS solutions > vol 20 n° 4 (October 2016) . - pp 655 - 664[article]Use of a GPS-derived troposphere model to improve InSAR deformation estimates in the San Gabriel Valley, California / Nicolas Houlié in IEEE Transactions on geoscience and remote sensing, vol 54 n° 9 (September 2016)PermalinkListening for RF noise : An analysis of pre-despreading GNSS interference detection techniques / Ali Jafarnia-Jahromi in Inside GNSS, vol 11 n° 3 (May - June 2016)PermalinkHigh-latitude ionospheric irregularity drift velocity estimation using spaced GPS receiver carrier phase time–frequency analysis / Jun Wang in IEEE Transactions on geoscience and remote sensing, vol 53 n° 11 (November 2015)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)PermalinkGalileo en route vers le GNSS / Bernard Bonhoure in XYZ, n° 144 (septembre - novembre 2015)PermalinkReal-time retrieval of precipitable water vapor from GPS and BeiDou observations / Cuixian Lu in Journal of geodesy, vol 89 n° 9 (september 2015)PermalinkUsing ionospheric corrections from the space-based augmentation systems for low earth orbiting satellites / Jeongrae Kim in GPS solutions, vol 19 n° 3 (July 2015)PermalinkStreet smart: 3-D city mapping and modeling for positioning with multi-GNSS / Li-Ta Hsu in GPS world, vol 26 n° 7 (July 2015)PermalinkTo L2C or not to L2C? That is the operational question / Alan Cameron in GPS world, vol 26 n° 7 (July 2015)PermalinkAccuracy and reliability of multi-GNSS real-time precise positioning: GPS, GLONASS, BeiDou, and Galileo / Xinging Li in Journal of geodesy, vol 89 n° 6 (June 2015)PermalinkNetwork-based estimation of time-dependent noise in GPS position time series / Ksenia Dimitrieva in Journal of geodesy, vol 89 n° 6 (June 2015)PermalinkVegetation sensing using GPS-interferometric reflectometry: theoretical effects of canopy parameters on signal-to-noise ratio data / C.C. Chew in IEEE Transactions on geoscience and remote sensing, vol 53 n° 5 (mai 2015)PermalinkCarrier-phase ambiguity resolution: Handling the biases for improved triple-frequency PPP convergence / Denis Laurichesse in GPS world, vol 26 n° 4 (April 2015)PermalinkGalileo E1 and E5a Performance for multi-frequency, multi-constellation GBAS / Mihaela-Simona Circiu in GPS world, vol 26 n° 4 (April 2015)PermalinkThree-Corner Hat for the assessment of the uncertainty of non-linear residuals of space-geodetic time series in the context of terrestrial reference frame analysis / Claudio Abbondanza in Journal of geodesy, vol 89 n° 4 (April 2015)PermalinkEstimating ionospheric delay using GPS/Galileo signals in the E5 band / Olivier Julien in Inside GNSS, vol 10 n° 2 (March - April 2015)PermalinkLevelling co-located GNSS and tide gauge stations using GNSS reflectometry / Alvaro Santamaria Gomez in Journal of geodesy, vol 89 n° 3 (March 2015)PermalinkAccounting for Galileo–GPS inter-system biases in precise satellite positioning / Jacek Paziewski in Journal of geodesy, vol 89 n° 1 (January 2015)PermalinkGPS for land surveyors / Jan Van Sickle (2015)PermalinkA Realistic and Easy-to-Implement Weighting Model for GPS Phase Observations / Xiaoguang Luo in IEEE Transactions on geoscience and remote sensing, vol 52 n° 10 tome 1 (October 2014)Permalink