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An efficient method to compensate receiver clock jumps in real-time precise point positioning / Shaoguang Xu in Remote sensing, vol 14 n° 20 (October-2 2022)  

Public [article]  inRemote sensing > vol 14 n° 20 (October-2 2022) . - n° 5222 Titre : An efficient method to compensate receiver clock jumps in real-time precise point positioning Type de document : Article/Communication Auteurs : Shaoguang Xu, Auteur ; Jialu Long, Auteur ; Jinling Wang, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 5222 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] ambiguïté entière [Termes IGN] décalage d'horloge [Termes IGN] erreur de positionnement [Termes IGN] glissement de cycle [Termes IGN] horloge du récepteur [Termes IGN] phase [Termes IGN] positionnement cinématique en temps réel [Termes IGN] positionnement par GNSS [Termes IGN] positionnement ponctuel précis [Termes IGN] retard troposphérique zénithal [Termes IGN] temps réel Résumé : (auteur) In global navigation satellite systems (GNSSs)-based positioning, user receiver clock jump is a common phenomenon on the low-cost receiver clocks and can break the continuity of observation time tag, carrier phase and pseudo range. The discontinuity may affect precise point positioning-related parameter estimation, including receiver clock error, position, troposphere and ionosphere parameters. It is important to note that these parameters can be used for timing, positioning, atmospheric inversion and so on. In response to this problem, the receiver clock jumps are divided into two types. The first one can be expressed by the carrier phase and pseudo range having the same scale jump, and the second one is that they are having different scale jumps. For the first type, if a small priori variance of receiver clock error is provided, it can affect the accuracy of ionospheric delay estimation both in static and kinematic mode, while in the latter mode, it also affects position estimation. However, if large process noise is provided, numerical problems may arise since other parameters’ process noises are usually small, it is proposed to use the single point positioning with pseudo ranges to provide a priori value of receiver clock error, and an empiric value is assigned to its prior variance, this handle can avoid the above problems. For the second type, instead of compensating so many raw observations in the traditional methods, it is proposed to compensate the ambiguities at the clock jump epochs only in a new method. The new method corrects the Melbourne–Wubbena (MW) combination firstly in order to avoid the misjudging of cycle slips for current epoch, and the second step is to compensate the corresponding ambiguities, then, after Kalman filtering, the MW and its mean should be corrected back in order to avoid the misjudging of cycle slips at the next epoch. This approach has the advantage of handling the clock jump epoch-wise and can avoid correcting the rest of the observations as the traditional methods used to. With the numerical validation examples both in static and kinematic modes, it shows the new method is simple but efficient for real time precise point positioning (PPP). Numéro de notice : A2022-792 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.3390/rs14205222 Date de publication en ligne : 19/10/2022 En ligne : https://doi.org/10.3390/rs14205222 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101909 [article]

On the detectability of mis-modeled biases in the network-derived positioning corrections and their user impact / Amir Khodabandeh in GPS solutions, vol 23 n° 3 (July 2019)  

Public [article]  inGPS solutions > vol 23 n° 3 (July 2019) Titre : On the detectability of mis-modeled biases in the network-derived positioning corrections and their user impact Type de document : Article/Communication Auteurs : Amir Khodabandeh, Auteur ; Jinling Wang, Auteur ; Chris Rizos, Auteur ; Ahmed El-Mowafy, Auteur Année de publication : 2019 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement [Termes IGN] correction [Termes IGN] filtre de Kalman [Termes IGN] inférence statistique [Termes IGN] intégrité des données [Termes IGN] modèle linéaire [Termes IGN] positionnement cinématique en temps réel [Termes IGN] positionnement par GNSS [Termes IGN] positionnement ponctuel précis [Termes IGN] précision du positionnement [Termes IGN] Receiver Autonomous Integrity Monitoring [Termes IGN] traitement de données GNSS Résumé : (auteur) High-precision single-receiver positioning requires the provision of reliable network-derived corrections. Care must therefore be exercised to continuously check the quality of the corrections and to detect the possible presence of mis-modeled biases in the network data. In network-RTK or its state-space implementation, PPP-RTK, quality control of the solutions is executed in two separate phases: the network component and the user component. Once confidence in the network-derived solutions is declared, a subset of the solutions is sent as corrections to a single-receiver user, thereby allowing the user to separately check the integrity of his network-aided model. In such a two-step integrity monitoring procedure, an intermediate step is missing, the integrity monitoring of the corrections themselves. It is the goal of this contribution to provide a quality control procedure for GNSS parameter solutions at the correction level, and to measure the impact a missed detection bias has on the (ambiguity-resolved) user position. New detection test statistics are derived with which the single-receiver user can check the overall validity of the corrections even before applying them to his data. A small-scale network of receivers is utilized to provide numerical insights into the detectability of mis-modeled biases using the proposed detectors and to analyze the impact of such biases on the user positioning performance. Numéro de notice : A2019-195 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-019-0863-x Date de publication en ligne : 14/05/2019 En ligne : https://doi.org/10.1007/s10291-019-0863-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92649 [article]

A geometric correspondence feature based-mismatch removal in vision based-mapping and navigation / Zeyu Li in Photogrammetric Engineering & Remote Sensing, PERS, vol 83 n° 10 (October 2017)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 83 n° 10 (October 2017) . - pp 693 - 704 Titre : A geometric correspondence feature based-mismatch removal in vision based-mapping and navigation Type de document : Article/Communication Auteurs : Zeyu Li, Auteur ; Jinling Wang, Auteur ; Charles Toth, Auteur Année de publication : 2017 Article en page(s) : pp 693 - 704 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] analyse de groupement [Termes IGN] appariement de données localisées [Termes IGN] attribut géomètrique [Termes IGN] erreur de positionnement [Termes IGN] regroupement de données [Termes IGN] vision par ordinateur Résumé : (auteur) Images with large-area repetitive texture, significant viewpoint, and illumination changes as well as occlusions often induce high-percentage keypoint mismatches, affecting the performance of vision-based mapping and navigation. Traditional methods for mismatch elimination tend to fail when the percentage of mismatches is high. In order to remove mismatches effectively, a new geometry-based approach is proposed in this paper, where Geometric Correspondence Feature (GCF) is used to represent the tentative correspondence. Based on the clustering property of GCFs from correct matches, a new clustering algorithm is developed to identify the cluster formed by the correct matches. With the defined quality factor calculated from the identified cluster, a Progressive Sample Consensus (PROSAC) process integrated with hyperplane-model is employed to further eliminate mismatches. Extensive experiments based on both simulated and real images in indoor and outdoor environments have demonstrated that the proposed approach can significantly improve the performance of mismatch elimination in the presence of high-percentage mismatches. Numéro de notice : A2017-690 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Article DOI : 10.14358/PERS.83.10.693 En ligne : https://doi.org/10.14358/PERS.83.10.693 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=87856 [article]

Modeling and assessment of triple-frequency BDS precise point positioning / Fei Guo in Journal of geodesy, vol 90 n° 11 (November 2016)  

Public [article]  inJournal of geodesy > vol 90 n° 11 (November 2016) . - pp 1223 - 1235 Titre : Modeling and assessment of triple-frequency BDS precise point positioning Type de document : Article/Communication Auteurs : Fei Guo, Auteur ; Xiaohong Zhang, Auteur ; Jinling Wang, Auteur ; Xiaodong Ren, Auteur Année de publication : 2016 Article en page(s) : pp 1223 - 1235 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] données BeiDou [Termes IGN] fréquence multiple [Termes IGN] positionnement par BeiDou [Termes IGN] positionnement par GNSS [Termes IGN] positionnement ponctuel précis [Termes IGN] signal BeiDou Résumé : (Auteur) The latest generation of GNSS satellites such as GPS BLOCK-IIF, Galileo and BDS are transmitting signals on three or more frequencies, thus having more choices in practice. At the same time, new challenges arise for integrating the new signals. This paper contributes to the modeling and assessment of triple-frequency PPP with BDS data. First, three triple-frequency PPP models are developed. The observation model and stochastic model are designed and extended to accommodate the third frequency. In particular, new biases such as differential code biases and inter-frequency biases as well as the parameterizations are addressed. Then, the relationships between different PPP models are discussed. To verify the triple-frequency PPP models, PPP tests with real triple-frequency data were performed in both static and kinematic scenarios. Results show that the three triple-frequency PPP models agree well with each other. Additional frequency has a marginal effect on the positioning accuracy in static PPP tests. However, the benefits of third frequency are significant in situations of where there is poor tracking and contaminated observations on frequencies B1 and B2 in kinematic PPP tests. Numéro de notice : A2016-799 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0920-y En ligne : http://dx.doi.org/10.1007/s00190-016-0920-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82579 [article]

vol 19 n° 3 - October 2016 - Special Issue: Mobile Mapping with Ubiquitous Point Clouds (Bulletin de Geo-spatial Information Science) / Bisheng Yang  

Public [n° ou bulletin]  est un bulletin de Geo-spatial Information Science / Wuhan technical university of surveying and mapping (1998 -)   Titre : vol 19 n° 3 - October 2016 - Special Issue: Mobile Mapping with Ubiquitous Point Clouds Type de document : Périodique Auteurs : Bisheng Yang, Éditeur scientifique ; Jinling Wang, Éditeur scientifique Année de publication : 2016 Langues : Français (fre) Numéro de notice : sans Affiliation des auteurs : non IGN Nature : Numéro de périodique En ligne : http://www.tandfonline.com/toc/tgsi20/19/3 Format de la ressource électronique : URL bulletin Permalink : https://documentation.ensg.eu/index.php?lvl=bulletin_display&id=28155 [n° ou bulletin]

Contient

• Automatic registration of MLS point clouds and SfM meshes of urban area / Reiji Yoshimura in Geo-spatial Information Science, vol 19 n° 3 (October 2016)  

A closed-form formula to calculate geometric dilution of precision (GDOP) for multi-GNSS constellations / Yunlong Teng in GPS solutions, vol 20 n° 3 (July 2016)  

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Rapid mapping method based on free blocks of surveys / Xianwen Yu in Journal of applied geodesy, vol 10 n° 2 (June 2016)  

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