Descripteur
Documents disponibles dans cette catégorie (427)



Etendre la recherche sur niveau(x) vers le bas
Assessing the positioning performance of GNSS receivers under different geomagnetic storm conditions / Chao Yan in Survey review, vol 54 n° 384 (May 2022)
![]()
[article]
Titre : Assessing the positioning performance of GNSS receivers under different geomagnetic storm conditions Type de document : Article/Communication Auteurs : Chao Yan, Auteur ; Qing Wang, Auteur ; Bo Zhang, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : pp 254 - 262 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse comparative
[Termes IGN] glissement de cycle
[Termes IGN] perturbation ionosphérique
[Termes IGN] positionnement ponctuel précis
[Termes IGN] récepteur GNSS
[Termes IGN] signal GNSS
[Termes IGN] tempête magnétiqueRésumé : (auteur) GNSS signals are affected when solar activity causes sudden variations in the density of the ionosphere. Few studies concentrate on positioning performance of IGS stations using different GNSS receivers under different geomagnetic storm conditions. This paper for the first time presents IF and UC PPP positioning performance of stations with different receivers during the quiet, moderate, intense, and super storms period. Firstly, a comprehensive investigation of geomagnetic storms effects on the occurrence of GPS cycle-slip and PPP positioning performance have been presented. Secondly, the influences of geomagnetic storms on the occurrence of cycle-slip and IF PPP positioning performance for stations using receivers provided by ‘JAVAD’, ‘LEICA’, and ‘TRIMBLE’ manufacturers have been comprehensively studied. Finally, this study investigates the geomagnetic storms effects on IF PPP positioning performance of stations using receiver types ‘JAVAD TRE_G3TH DELTA’, ‘JAVAD TRE_3 DELTA’, ‘LEICA GR25’, and ‘TRIMBLE NETR9’ by analysing observed data collected at mid-latitude region. Numéro de notice : A2022-356 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2021.1924967 Date de publication en ligne : 13/05/2021 En ligne : https://doi.org/10.1080/00396265.2021.1924967 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100555
in Survey review > vol 54 n° 384 (May 2022) . - pp 254 - 262[article]Coastal observation of sea surface tide and wave height using opportunity signal from Beidou GEO satellites: analysis and evaluation / Feng Wang in Journal of geodesy, vol 96 n° 4 (April 2022)
![]()
[article]
Titre : Coastal observation of sea surface tide and wave height using opportunity signal from Beidou GEO satellites: analysis and evaluation Type de document : Article/Communication Auteurs : Feng Wang, Auteur ; Dongkai Yang, Auteur ; Guodong Zhang, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 17 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] Chine
[Termes IGN] données altimétriques
[Termes IGN] données marégraphiques
[Termes IGN] hauteurs de mer
[Termes IGN] méthode de Monte-Carlo
[Termes IGN] modèle géométrique
[Termes IGN] rapport signal sur bruit
[Termes IGN] récepteur GNSS
[Termes IGN] réflectométrie par GNSS
[Termes IGN] signal BeiDou
[Termes IGN] surface de la mer
[Termes IGN] vagueRésumé : (auteur) In this paper, the methods retrieving tide and SWH using reflected BeiDou GEO satellite signals are proposed, and a data-driven method is proposed to calibrate sea state bias of the retrieved tide. In addition, an estimator combining multi-satellite observation based on linear unbiased minimum variance (LUMV) is developed to improve the retrieved precision. The B1I signal experiments in Qingdao and Shenzhen show after calibrating sea state influence using the proposed method, the root-mean-square error (RMSE) could fall to 0.40 m from 0.45 m, and compared to the single-satellite observation, the multi-satellite observation based on the LUMV estimator could significantly reduce the RMSE of the retrieved tide to 0.16 m. Shenzhen experiment is also used to evaluate the performance of retrieving SWH and the determination coefficient of 0.60 is obtained. This paper also conducts Monte Carlo simulation and experiment to evaluate the altimetry and measuring SWH precision using reflected B3I signal. The simulated results when SNR is over 5 dB, incoherent averaging number is 10000, and the receiver bandwidth is over 45 MHz, the estimated precision of the delay can reach up ∼0.15 m, and the precision of the normalized area ranges from 0.2 to 0.3 m. The B3I experiment show that compared to B1I signal, when the reflected signal from individual satellite is used, the better precision with the RMSE of 0.25 can be obtained, and when combining the measurements from the three satellites using LUMV estimator, the RMSE reduces to 0.16 m. Further, the precision of 0.12 m can be obtained by calibrating the sea state influence. Numéro de notice : A2022-213 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-022-01605-0 Date de publication en ligne : 06/03/2022 En ligne : https://doi.org/10.1007/s00190-022-01605-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100050
in Journal of geodesy > vol 96 n° 4 (April 2022) . - n° 17[article]Detection and mitigation of GNSS spoofing via the pseudorange difference between epochs in a multicorrelator receiver / Xiangyong Shang in GPS solutions, vol 26 n° 2 (April 2022)
![]()
[article]
Titre : Detection and mitigation of GNSS spoofing via the pseudorange difference between epochs in a multicorrelator receiver Type de document : Article/Communication Auteurs : Xiangyong Shang, Auteur ; Fuping Sun, Auteur ; Lundong Zhang, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 37 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] anti-leurrage
[Termes IGN] atténuation du signal
[Termes IGN] brouillage
[Termes IGN] détection de leurrage
[Termes IGN] détection du signal
[Termes IGN] filtre de Kalman
[Termes IGN] mesurage de pseudo-distance
[Termes IGN] méthode du maximum de vraisemblance (estimation)
[Termes IGN] qualité du signal
[Termes IGN] récepteur GNSS
[Termes IGN] signal GNSSRésumé : (auteur) Spoofing attacks have become an increasing threat to global navigation satellite system receivers. Existing anti-spoofing algorithms concentrate on the detection of these attacks; however, they are unable to prevent the counterfeit signal, which causes false position and timing results. Some defense techniques require the assistance of other sensors or measurement devices located at different positions. These impose many restrictions on the practical applications of anti-spoofing algorithms. In this study, the multicorrelator estimator, designed initially to prevent multipath signals, is applied to detect and mitigate spoofing. A statistic is proposed for spoofing detection based on the code phase difference between counterfeit and authentic signals. This statistic can significantly reduce the rate of false and missed alarms. Assuming there is no spoofing at the beginning, the pseudorange difference between epochs is derived for spoofing validation, allowing spoofing suppression in a single receiver. Based on this study, an estimation-validation-mitigation structure is presented. A robust extended Kalman filter is proposed to reduce gross errors in the multicorrelator measurements and improve estimation accuracy. Public-spoofing datasets recorded in real environments were used to verify the performance of different parameters. A total of 81 complex correlators were introduced in the experiments. Results show that using the proposed scheme, the position or time offsets caused by spoofing drop from 600 m to approximately 20 m, and the spoofing is mitigated considerably. The proposed method provides an effective anti-spoofing structure that requires only a single antenna and does not require additional sensors. Numéro de notice : A2022-108 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-022-01224-4 Date de publication en ligne : 16/01/2022 En ligne : https://doi.org/10.1007/s10291-022-01224-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99610
in GPS solutions > vol 26 n° 2 (April 2022) . - n° 37[article]Validating the impact of various ionosphere correction on mid to long baselines and point positioning using GPS dual-frequency receivers / Alaa A. Elghazouly in Journal of applied geodesy, vol 16 n° 2 (April 2022)
![]()
[article]
Titre : Validating the impact of various ionosphere correction on mid to long baselines and point positioning using GPS dual-frequency receivers Type de document : Article/Communication Auteurs : Alaa A. Elghazouly, Auteur ; Mohamed Doma, Auteur ; Ahmed Sedeek, Auteur Année de publication : 2022 Article en page(s) : pp 81 - 90 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] correction ionosphérique
[Termes IGN] ligne de base
[Termes IGN] modèle ionosphérique
[Termes IGN] positionnement ponctuel précis
[Termes IGN] récepteur bifréquence
[Termes IGN] récepteur GPS
[Termes IGN] tempête magnétique
[Termes IGN] teneur verticale totale en électronsRésumé : (auteur) Due to the ionosphere delay, which has become the dominant GPS error source, it is crucial to remove the ionospheric effect before estimating point coordinates. Therefore, different agencies started to generate daily Global Ionosphere Maps (GIMs); the Vertical Total Electron Content (VTEC) values represented in GIMs produced by several providers can be used to remove the ionosphere error from observations. In this research, an analysis will be carried with three sources for VTEC maps produced by the Center for Orbit Determination in Europe (CODE), Regional TEC Mapping (RTM), and the International Reference Ionosphere (IRI). The evaluation is focused on the effects of a specific ionosphere GIM correction on the precise point positioning (PPP) solutions. Two networks were considered. The first network consists of seven Global Navigation Satellite Systems (GNSS) receivers from (IGS) global stations. The selected test days are six days, three of them quiet, and three other days are stormy to check the influence of geomagnetic storms on relative kinematic positioning solutions. The second network is a regional network in Egypt. The results show that the calculated coordinates using the three VTEC map sources are far from each other on stormy days rather than on quiet days. Also, the standard deviation values are large on stormy days compared to those on quiet days. Using CODE and RTM IONEX file produces the most precise coordinates after that the values of IRI. The elimination of ionospheric biases over the estimated lengths of many baselines up to 1000 km has resulted in positive findings, which show the feasibility of the suggested assessment procedure. Numéro de notice : A2022-250 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2021-0040 Date de publication en ligne : 27/11/2021 En ligne : https://doi.org/10.1515/jag-2021-0040 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100203
in Journal of applied geodesy > vol 16 n° 2 (April 2022) . - pp 81 - 90[article]A multipath and thermal noise joint error characterization and exploitation for low-cost GNSS PVT estimators in urban environment / Eustachio Roberto Matera (2022)
![]()
Titre : A multipath and thermal noise joint error characterization and exploitation for low-cost GNSS PVT estimators in urban environment Type de document : Thèse/HDR Auteurs : Eustachio Roberto Matera, Auteur ; Carl Milner, Directeur de thèse ; Axel Javier Garcia Pena, Directeur de thèse Editeur : Toulouse : Université de Toulouse Année de publication : 2022 Importance : 348 p. Format : 21 x 30 cm Note générale : Bibliographie
Thèse en vue de l'obtention du Doctorat de l'Université de Toulouse délivré par l'Institut National Polytechnique de Toulouse en Informatique et TélécommunicationLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] bruit thermique
[Termes IGN] correction du trajet multiple
[Termes IGN] corrélation temporelle
[Termes IGN] filtre de Kalman
[Termes IGN] rapport signal sur bruit
[Termes IGN] récepteur GNSS
[Termes IGN] signal GPS
[Termes IGN] trajet multiple
[Termes IGN] zone urbaine denseIndex. décimale : THESE Thèses et HDR Résumé : (auteur) Achieving an accurate localization is a significant challenge for low-cost GNSS devices in dense urban areas. The main limitations are encountered in the urban canyons, consisting in a reduced satellite signal availability and a positioning estimation error due to the impact of Line-of-Sight and Non Line-of-Sight multipath phenomenon. This PhD study allows to understand the impact of the multipath phenomenon on the low-cost GNSS receivers and to prove the need of accurate assessment of the multipath error model affecting the GNSS measurements, especially in urban environment. It consists in the investigation, characterization, and finally, exploitation of the multipath error components affecting the pseudorange and pseudorange-rate measurements, of a single frequency, dual constellation GNSS receiver in the urban environment, operating with GPS L1 C/A and Galileo E1 OS signals. The first goal consists in providing a set of methodologies able to identify, isolate and characterize the multipath error components from the measurements under test. However, considering that the isolation of the multipath error is a complex operation due to the superimposed effects of multipath and thermal noise, the final method consists of isolating the joint contribution of multipath and thermal noise components. The isolated multipath and thermal noise error components are firstly classified depending the corresponding received signal /0 values, and, secondly, statistically characterized by means of Probability Density Function, sample mean and sample variance. Also, the temporal and spatial correlation properties of the isolated error components are calculated by means of a methodology which estimates the temporal correlations as a function of the receiver speed. In addition, an image processing methodology based on the application of a sky-facing fish-eye camera provides the determination of an empirical /0 threshold equal to 35 dB-Hz used to qualitatively identify the Non Line- Of-Sight and Line-Of-Sight received signal reception states. The resulting errors are characterized by a nonsymmetrical, positive biased PDF for a /0 lower than 35 dBHz, while they are characterized by a symmetrical and zero-centred PDF for a /0 higher than 35 dB-Hz. Correlation times for pseudoranges are ranged from around 5s for static and very low speed dynamics to around 1s for high-speed dynamics. Correlation times for pseudorange-rates ranged from around 0.5s for static and very low speed dynamics to around 0.2s for high-speed dynamics, due to the data-rate limitations. The second goal consists in exploiting the multipath and thermal noise error models and the LOS/NLOS received signal reception state estimation in a low-complex EKF-based architecture to improve the accuracy of the PVT estimates. This is obtained by implementing some techniques based on the measurement weighting approach to take into account the statistical properties of the error under exam and by the application of a time differenced architecture design to exploit the temporal correlation properties. Positioning performance of the tested solutions surpassed the performances of a simple EKF architecture and are comparable to the performances of a uBlox M8T receiver. Note de contenu : 1- Introduction
2- GNSS architecture
3- GNSS receiver processing
4- Multipath effects on the GNSS receiver tracking performances
5- Multipath characterization methodologies
6- Multipath characterization results
7- Proposed extended Kalman Filter Algorithm
8- Conclusions and recommandations for future worksNuméro de notice : 15272 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse française Note de thèse : Thèse de Doctorat: en Informatique et Télécommunication : Toulouse :2022 Organisme de stage : (TELECOM-ENAC) DOI : sans En ligne : http://www.theses.fr/2022INPT0030 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100992 On-orbit BDS signals and transmit antenna gain analysis for a geostationary satellite / Meng Wang in Advances in space research, vol 69 n° 7 (April 2022)
PermalinkPermalinkPermalinkSentinel-6A precise orbit determination using a combined GPS/Galileo receiver / Oliver Montenbruck in Journal of geodesy, vol 95 n° 10 (October 2021)
PermalinkGPS satellite differential code bias estimation with current eleven low earth orbit satellites / Xingxing Li in Journal of geodesy, vol 95 n° 7 (July 2021)
PermalinkA multi-layer perceptron neural network to mitigate the interference of time synchronization attacks in stationary GPS receivers / N. Orouji in GPS solutions, vol 25 n° 3 (July 2021)
PermalinkRécepteurs GNSS bas coût pour la surveillance des grands ponts / Nicolas Manzini in XYZ, n° 167 (juin 2021)
PermalinkMulti-GNSS real-time precise clock estimation considering the correction of inter-satellite code biases / Liang Chen in GPS solutions, vol 25 n° 2 (April 2021)
PermalinkThe Realization and evaluation of PPP ambiguity resolution with INS aiding in marine survey / Zhenqiang Du in Marine geodesy, vol 44 n° 2 (March 2021)
PermalinkMitigating high latitude ionospheric scintillation effects on GNSS Precise Point Positioning exploiting 1-s scintillation indices / Kai Guo in Journal of geodesy, vol 95 n° 3 (March 2021)
Permalink