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A tropospheric delay model to integrate ERA5 and GNSS reference network for mountainous areas: application to precise point positioning / Cuixian Lu in GPS solutions, vol 27 n° 2 (April 2023)
[article]
Titre : A tropospheric delay model to integrate ERA5 and GNSS reference network for mountainous areas: application to precise point positioning Type de document : Article/Communication Auteurs : Cuixian Lu, Auteur ; Yaxin Zhong, Auteur ; Zhilu Wu, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : n° 81 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Australie
[Termes IGN] Continuously Operating Reference Station network
[Termes IGN] convergence
[Termes IGN] ERA5
[Termes IGN] montagne
[Termes IGN] positionnement ponctuel précis
[Termes IGN] retard troposphérique
[Termes IGN] retard troposphérique zénithal
[Termes IGN] station GNSS
[Termes IGN] teneur en vapeur d'eauRésumé : (auteur) In this study, a tropospheric delay model that integrates tropospheric delays derived from the European Centre for Medium-Range Weather Forecasts fifth-generation global atmospheric reanalysis and the Continuously Operating Reference Station (CORS) network observations in mountainous areas is established, which is then applied to improve GNSS precise point positioning (PPP). Observations of GNSS stations in the Great Dividing Range of eastern Australia are selected for the experiments. The performance of zenith wet delay (ZWD) retrieved from the integrated tropospheric model is evaluated with comparisons to precise point positioning (PPP) estimated ZWD values. Results show that the average root-mean-square value for ZWDs of the integrated tropospheric model is 8.03 mm for the eastern Australian CORS network, showing an improvement of 14.0% compared to that of the CORS interpolation model. Besides, the proposed tropospheric model is applied to regional augmentation precise positioning. Results present that the average positioning accuracy of the tropospheric model-corrected PPP solutions is 1.42 cm, 1.39 cm and 2.90 cm for the east, north and vertical components, respectively, revealing an improvement of 14.5%, 11.5% and 18.6% compared to the PPP solutions with regional CORS corrections. Meanwhile, almost all stations can achieve a faster solution convergence by performing the integrated tropospheric model-corrected PPP. All these results demonstrate the promising potential of the proposed tropospheric model in enhancing precise positioning as well as facilitating applications in the meteorological fields. Numéro de notice : A2023-183 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-023-01425-5 Date de publication en ligne : 03/03/2023 En ligne : https://doi.org/10.1007/s10291-023-01425-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102954
in GPS solutions > vol 27 n° 2 (April 2023) . - n° 81[article]A unified cycle-slip, multipath estimation, detection and mitigation method for VIO-aided PPP in urban environments / Bo Xu in GPS solutions, vol 27 n° 2 (April 2023)
[article]
Titre : A unified cycle-slip, multipath estimation, detection and mitigation method for VIO-aided PPP in urban environments Type de document : Article/Communication Auteurs : Bo Xu, Auteur ; Shoujian Zhang, Auteur ; Kaifa Kuang, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : n° 59 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] filtre de Kalman
[Termes IGN] glissement de cycle
[Termes IGN] milieu urbain
[Termes IGN] modèle stochastique
[Termes IGN] navigation autonome
[Termes IGN] navigation inertielle
[Termes IGN] odomètre
[Termes IGN] phase
[Termes IGN] positionnement ponctuel précis
[Termes IGN] signal GNSS
[Termes IGN] trajet multipleRésumé : (auteur) Accurate, continuous and reliable positioning is required in autonomous driving. The precise point positioning (PPP) technique, which can provide a global accurate positioning service using a single global navigation satellite system (GNSS) receiver, has attracted much attention. Nevertheless, due to the cycle slips and multipath effects in the GNSS signal, the performance of PPP is severely degraded in urban areas, which has a negative effect on the PPP/inertial navigation system (INS)/vision integrated navigation. Moreover, the carrier phase observations with un-modeled multipath cause false detection of small cycle slips and lead to deviation in the state variable estimation in PPP. Therefore, an effective cycle slip/multipath estimation, detection and mitigation (EDM) method is proposed. A clustering method is used to separate the cycle slips and multipath from the carrier phase observations aided by visual inertial odometry (VIO) positioning results. The influence of the carrier phase multipath on state variable estimation is reduced by adjusting the stochastic ambiguity model in the Kalman filter. The proposed EDM method is validated by vehicle experiments conducted in urban and freeway areas. Experimental results demonstrate that 0.2% cycle slip detection error is achieved by our method. Besides, the multipath estimation accuracy of EDM improves by more than 50% compared with the geometry-based (GB) method. Regarding positioning accuracy, the EDM method has a maximum of 72.2% and 63.2% improvement compared to traditional geometry-free (GF) and GB methods. Numéro de notice : A2023-124 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-023-01396-7 Date de publication en ligne : 17/01/2023 En ligne : https://doi.org/10.1007/s10291-023-01396-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102501
in GPS solutions > vol 27 n° 2 (April 2023) . - n° 59[article]Assessment of VRS performances of the Algerian-CORS-network / Takka Elhadi in Bulletin des sciences géographiques, vol 27 n° 1 (2023)
[article]
Titre : Assessment of VRS performances of the Algerian-CORS-network Type de document : Article/Communication Auteurs : Takka Elhadi, Auteur ; Touabet Touabet, Auteur ; Boudrassene Abdennour, Auteur Année de publication : 2023 Article en page(s) : pp 25 - 33 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] affaiblissement géométrique de la précision
[Termes IGN] Algérie
[Termes IGN] disponibilité des données
[Termes IGN] intégrité des données
[Termes IGN] performance
[Termes IGN] précision du positionnement
[Termes IGN] répétabilité
[Termes IGN] réseau géodésique local
[Termes IGN] réseau géodésique permanent
[Termes IGN] station de référenceRésumé : (auteur) The Algerian Continuously Operating Reference Stations Network, so-called AL-CORS-Net, is deployed to provideNRTK services based onVRS method using Geo++GNSMART software.This paper investigates VRS performance in terms ofprecision, availability, integrity, Time-to-Fix-Ambiguity (TTFA), repeatability and PDOP.Several survey sessions were performed at different sites in the north of Algeria during October 2021 to January 2022. The results revealed good performance indicators; the precision was in the order of 1.3 cm in the horizontal component and about 2.2 cm in the vertical (at 1 sigma). The VRS solution's availability was 97.25%, its integrity was 98.8% in the horizontal and 94.9% in the vertical, and the TTFA ranged from a few seconds to a few minutes. The VRS measurements' repeatability presented similar measurement results throughout time. High satellite numbers have been tracked, their geometry (PDOP) was ideal. Numéro de notice : A2023-090 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans En ligne : https://www.asjp.cerist.dz/en/downArticle/213/27/1/216928 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=103152
in Bulletin des sciences géographiques > vol 27 n° 1 (2023) . - pp 25 - 33[article]Exemplaires(1)
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Assessment of VRS performances ... - pdf éditeurAdobe Acrobat PDF Atmospheric water vapor measurement in order to estimate continental precipitation over Algeria region based on the INCT-GNSS network / Abdellaoui Hassen in Bulletin des sciences géographiques, vol 27 n° 1 (2023)
[article]
Titre : Atmospheric water vapor measurement in order to estimate continental precipitation over Algeria region based on the INCT-GNSS network Type de document : Article/Communication Auteurs : Abdellaoui Hassen, Auteur ; Ali Omar Hammou, Auteur ; Soraya Makhlouf, Auteur ; Naima Zaourar, Auteur ; Mohamed Aïssa Meslem, Auteur Année de publication : 2023 Article en page(s) : pp 42 - 47 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Algérie
[Termes IGN] climat méditerranéen
[Termes IGN] données GNSS
[Termes IGN] données météorologiques
[Termes IGN] Méditerranée, mer
[Termes IGN] précipitation
[Termes IGN] teneur en vapeur d'eauRésumé : (auteur) Northern Algeria region is characterized a Mediterranean climate, cold, humid, dry winters and warm summers, same as other countries in the world, and is exposed to desertification problems. Along its coast, the average annual precipitation is 384 mm, so more than 75% of its territory has an annual precipitation lower than 384 mm. This is a global problem that affects a large number of people and land, and is now one of the most important environmental problems in Algeria. The work presented in this paper describe a preliminary study of GNSS meteorology technique based on GNSS positioning and estimation of the tropospheric water vapor quantity based exclusively on the INCT-GNSS network. According to our results, we noted that the integrated content of water vapor is a highly variable parameter that depends on the study region, in our study it is between the South and the North of Algeria, this variation is related to the geographical position in relation to the Mediterranean Sea, as well as the season, noticing that during the winter the quantities of water vapor are low compared to the summer. No relationship could be found between GNSS IWV and precipitation values, except for a significant increase in GNSS IWV that frequently precedes the arrival of precipitation. Improving atmospheric observation techniques and understanding of the key processes of precipitation formation is thus a major challenge for our society. In fact, a better prediction of precipitation would allow bettering anticipating the occurrence of floods and consequently to minimize the damages related to these events. Numéro de notice : A2023-091 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans En ligne : https://www.asjp.cerist.dz/en/downArticle/213/27/1/216930 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=103153
in Bulletin des sciences géographiques > vol 27 n° 1 (2023) . - pp 42 - 47[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 253-2023011 RAB Revue Centre de documentation En réserve L003 Disponible Documents numériques
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Atmospheric water vapor measurementAdobe Acrobat PDF Determination of Helmert transformation parameters for continuous GNSS networks: a case study of the Géoazur GNSS network / Dinh Trong Tran in Geo-spatial Information Science, vol 26 n° 1 (March 2023)
[article]
Titre : Determination of Helmert transformation parameters for continuous GNSS networks: a case study of the Géoazur GNSS network Type de document : Article/Communication Auteurs : Dinh Trong Tran, Auteur ; Jean-Mathieu Nocquet , Auteur ; Ngoc Dung Luong, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : pp 125 - 138 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] données GNSS
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] méthode des moindres carrés
[Termes IGN] transformation de coordonnées
[Termes IGN] transformation de Helmert
[Termes IGN] valeur aberranteRésumé : (auteur) In this paper, we propose an approach to determine seven parameters of the Helmert transformation by transforming the coordinates of a continuous GNSS network from the World Geodetic System 1984 (WGS84) to the International Terrestrial Reference Frame. This includes (1) converting the coordinates of common points from the global coordinate system to the local coordinate system, (2) identifying and eliminating outliers by the Dikin estimator, and (3) estimating seven parameters of the Helmert transformation by least squares (LS) estimation with the “clean” data (i.e. outliers removed). Herein, the local coordinate system provides a platform to separate points’ horizontal and vertical components. Then, the Dikin estimator identifies and eliminates outliers in the horizontal or vertical component separately. It is significant because common points in a continuous GNSS network may contain outliers. The proposed approach is tested with the Géoazur GNSS network with the results showing that the Dikin estimator detects outliers at 6 out of 18 common points, among which three points are found with outliers in the vertical component only. Thus, instead of eliminating all coordinate components of these six common points, we only eliminate all coordinate components of three common points and only the vertical component of another three common points. Finally, the classical LS estimation is applied to “clean” data to estimate seven parameters of the Helmert transformation with a significant accuracy improvement. The Dikin estimator’s results are compared to those of other robust estimators of Huber and Theil-Sen, which shows that the Dikin estimator performs better. Furthermore, the weighted total least-squares estimation is implemented to assess the accuracy of the LS estimation with the same data. The inter-comparison of the seven estimated parameters and their standard deviations shows a small difference at a few per million levels (E-6). Numéro de notice : A2023-208 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/10095020.2022.2138569 Date de publication en ligne : 15/11/2022 En ligne : https://doi.org/10.1080/10095020.2022.2138569 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=103135
in Geo-spatial Information Science > vol 26 n° 1 (March 2023) . - pp 125 - 138[article]Enabling RTK positioning under jamming: Mitigation of carrier-phase distortions induced by blind spatial filtering / Tobias Bamberg in Navigation : journal of the Institute of navigation, vol 70 n° 1 (Spring 2023)PermalinkEvaluation of strategies for the ultra-rapid orbit prediction of BDS GEO satellites / Wenxi Zhao in Geo-spatial Information Science, vol 26 n° 1 (March 2023)PermalinkImproved GPS-based single-frequency orbit determination for the CYGNSS spacecraft using GipsyX / Alex V. Conrad in Navigation : journal of the Institute of navigation, vol 70 n° 1 (Spring 2023)PermalinkIterative data assimilation approach for the refinement of marine geoid models using sea surface height and dynamic topography datasets / Sander Varbla in Journal of geodesy, vol 97 n° 3 (March 2023)PermalinkA new algebraic solution for transforming Cartesian to geodetic coordinates / Jia-Chun Guo in Survey review, vol 55 n° 389 (March 2023)PermalinkPeut-on prédire les séismes ? / Laurent Polidori in Géomètre, n° 2211 (mars 2023)PermalinkSeismic deformation in the Adriatic Sea region / B. Orecchio in Journal of geodynamics, vol 155 (March 2023)PermalinkThe importance of co-located VLBI Intensive stations and GNSS receivers / Christopher Dieck in Journal of geodesy, vol 97 n° 3 (March 2023)PermalinkBDS-3 precise orbit and clock solution at Wuhan University: status and improvement / Jing Guo in Journal of geodesy, vol 97 n° 2 (February 2023)PermalinkCoastal GNSS-R phase altimetry based on the combination of L1 and L5 signals under high sea states / Yunqiao He in Journal of geodesy, vol 97 n° 2 (February 2023)Permalink