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New data processing strategy for single frequency GPS deformation monitoring / S-Q. Huang in Survey review, vol 47 n° 344 (September 2015)
[article]
Titre : New data processing strategy for single frequency GPS deformation monitoring Type de document : Article/Communication Auteurs : S-Q. Huang, Auteur ; J-X. Wang, Auteur Année de publication : 2015 Article en page(s) : pp 379 - 385 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] ligne de base
[Termes IGN] récepteur monofréquence
[Termes IGN] réseau de surveillance géophysique
[Termes IGN] retard ionosphèrique
[Termes IGN] surveillance
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) Although the application of the single frequency receiver in GPS deformation monitoring is limited mainly by the effect of the ionospheric delays, the relevant studies have never been stopped due to the much cheaper price of the single frequency receivers. In this paper, we introduce a new data processing strategy for the deformation monitoring network where the baselines between any two nearest stations are processed instead of the baselines formed only between the reference stations and monitoring stations in the traditional strategy. As a result, most of the baselines in the monitoring networks are very short so as to the ionospheric effects can be safely ignored. The results from the experiments show that the new strategy can eliminate the effect of ionospheric delay by processing the short baselines in the network mode. The accuracy and integrity of the deformation solutions can be improved by the presented strategy. Numéro de notice : A2015-919 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270614Y.0000000138 En ligne : https://doi.org/10.1179/1752270614Y.0000000138 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79710
in Survey review > vol 47 n° 344 (September 2015) . - pp 379 - 385[article]Ionospheric effects in uncalibrated phase delay estimation and ambiguity-fixed PPP based on raw observable model / Shengfeng Gu in Journal of geodesy, vol 89 n° 5 (May 2015)
[article]
Titre : Ionospheric effects in uncalibrated phase delay estimation and ambiguity-fixed PPP based on raw observable model Type de document : Article/Communication Auteurs : Shengfeng Gu, Auteur ; Chuang Shi, Auteur ; Yidong Lou, Auteur ; Jingnan Liu, Auteur Année de publication : 2015 Article en page(s) : pp 447 - 457 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] correction ionosphérique
[Termes IGN] modèle ionosphérique
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] positionnement ponctuel précis
[Termes IGN] propagation ionosphérique
[Termes IGN] résolution d'ambiguïté
[Termes IGN] retard ionosphèrique
[Termes IGN] signal GNSS
[Termes IGN] teneur totale en électronsRésumé : (auteur) Zero-difference (ZD) ambiguity resolution (AR) reveals the potential to further improve the performance of precise point positioning (PPP). Traditionally, PPP AR is achieved by Melbourne–Wübbena and ionosphere-free combinations in which the ionosphere effect are removed. To exploit the ionosphere characteristics, PPP AR with L1 and L2 raw observable has also been developed recently. In this study, we apply this new approach in uncalibrated phase delay (UPD) generation and ZD AR and compare it with the traditional model. The raw observable processing strategy treats each ionosphere delay as an unknown parameter. In this manner, both a priori ionosphere correction model and its spatio-temporal correlation can be employed as constraints to improve the ambiguity resolution. However, theoretical analysis indicates that for the wide-lane (WL) UPD retrieved from L1/L2 ambiguities to benefit from this raw observable approach, high precision ionosphere correction of better than 0.7 total electron content unit (TECU) is essential. This conclusion is then confirmed with over 1 year data collected at about 360 stations. Firstly, both global and regional ionosphere model were generated and evaluated, the results of which demonstrated that, for large-scale ionosphere modeling, only an accuracy of 3.9 TECU can be achieved on average for the vertical delays, and this accuracy can be improved to about 0.64 TECU when dense network is involved. Based on these ionosphere products, WL/narrow-lane (NL) UPDs are then extracted with the raw observable model. The NL ambiguity reveals a better stability and consistency compared to traditional approach. Nonetheless, the WL ambiguity can be hardly improved even constrained with the high spatio-temporal resolution ionospheric corrections. By applying both these approaches in PPP-RTK, it is interesting to find that the traditional model is more efficient in AR as evidenced by the shorter time to first fix, while the three-dimensional positioning accuracy of the RAW model outperforms the combination model by about 7.9%. This reveals that, with the current ionosphere models, there is actually no optimal strategy for the dual-frequency ZD ambiguity resolution, and the combination approach and raw approach each has merits and demerits. Numéro de notice : A2015-345 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-015-0789-1 Date de publication en ligne : 15/02/2015 En ligne : https://doi.org/10.1007/s00190-015-0789-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76717
in Journal of geodesy > vol 89 n° 5 (May 2015) . - pp 447 - 457[article]Estimating ionospheric delay using GPS/Galileo signals in the E5 band / Olivier Julien in Inside GNSS, vol 10 n° 2 (March - April 2015)
[article]
Titre : Estimating ionospheric delay using GPS/Galileo signals in the E5 band Type de document : Article/Communication Auteurs : Olivier Julien, Auteur ; Jean-Luc Issler, Auteur ; Laurent Lestarquit, Auteur ; Lionel Ries, Auteur Année de publication : 2015 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] modèle ionosphérique
[Termes IGN] retard ionosphèrique
[Termes IGN] signal Galileo
[Termes IGN] signal GPS
[Termes IGN] traitement du signalRésumé : (éditeur) Building on previous research efforts, the authors present a novel technique to improve ionospheric modeling using various configurations of GPS and Galileo signals in the E5 band. Numéro de notice : A2015-253 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans En ligne : http://www.insidegnss.com/node/4435 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76293
in Inside GNSS > vol 10 n° 2 (March - April 2015)[article]Assessing and mitigating the effects of the ionospheric variability on DGPS / Duojie Weng in GPS solutions, vol 19 n° 1 (January 2015)
[article]
Titre : Assessing and mitigating the effects of the ionospheric variability on DGPS Type de document : Article/Communication Auteurs : Duojie Weng, Auteur ; Shengyue Ji, Auteur ; Wu Chen, Auteur ; Zhihua Li, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 107 - 116 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] GPS en mode différentiel
[Termes IGN] gradient ionosphèrique
[Termes IGN] ionosphère
[Termes IGN] modèle ionosphérique
[Termes IGN] retard ionosphèrique
[Termes IGN] traitement de données GNSSRésumé : (auteur) The differential GPS (DGPS) performance can be affected by the ionospheric variability, especially in low-latitude areas. We evaluated the behavior of the ionospheric variability in low-latitude areas in the 11-year cycle of the solar activity. During periods of solar maximum, the percentage of the daily maximum gradient that exceeds 50 mm/km has reached 73 % in 2001. Assuming that the baseline length is 20 km, the gradient larger than 50 mm/km can lead to more than 1.0-m ranging error, which is significant if we want to achieve meter-level accuracy with DGPS. An ionospheric gradient model built from a number of reference stations is proposed for estimating the differential ionospheric delays. The effectiveness of the model is demonstrated under both the quiet and active ionospheric conditions in low-latitude areas. For a short baseline length of 16.9 km in Hong Kong, the horizontal positioning accuracy can be improved by 41 and 61 % during active solar years and geomagnetic storms, respectively. The improvements show that the model is capable of reducing the spatial decorrelation caused by the ionospheric variability, and the model can be used in DGPS especially over the regions, such as low-latitude areas, where the large ionospheric variability happens frequently. Numéro de notice : A2015-201 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-014-0372-x Date de publication en ligne : 13/04/2014 En ligne : https://doi.org/10.1007/s10291-014-0372-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76019
in GPS solutions > vol 19 n° 1 (January 2015) . - pp 107 - 116[article]
Titre : Analysis of GNSS raw observations in PPP solutions Type de document : Thèse/HDR Auteurs : Erik Schönemann, Auteur Editeur : Darmstadt [Allemagne] : Technische Universität Darmstadt Année de publication : 2014 Collection : Schriftenreihe der Fachrichtung Geodäsie num. 42 Importance : 133 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-935631-31-0 Note générale : Vom Fachbereich Bau- und Umweltingenieurwissenschaften der Technischen Universität Darmstadt zur Erlangung des akademischen Grades eines Doktor-Ingenieurs (Dr.-Ing.) genehmigte Dissertation Langues : Anglais (eng) Descripteur : [Termes IGN] données GNSS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] retard ionosphèrique
[Termes IGN] retard troposphérique
[Termes IGN] traitement de données GNSS
[Termes IGN] traitement du signal
[Vedettes matières IGN] Traitement de données GNSSIndex. décimale : 30.61 Systèmes de Positionnement par Satellites du GNSS Résumé : (auteur) Global navigation satellite systems (GNSS) are an essential component in many areas of our daily life. They find application in diverse fields of private, commercial and scientific activities and are employed to meet the needs of police and military. Their fundamental importance for industrial countries is not the least the triggering point for the continuing modernisation of the existing and the development of new systems. The global satellite navigation systems are supplemented by regional satellite navigation systems (RNSS) and satellite based augmentation systems (SBAS). The diversity of systems, applied signal modulations and carrier frequencies, in particular in their combination, provide a broad range of opportunities along with new challenges.
The work presented herein focuses on the use of satellite navigation systems for precise positioning and timing applications and scientific analysis. For best and comprehensive results, an equivalent combination of all available systems and signals is a fundamental requirement. For these reasons, relative approaches based on observation differences are rather inappropriate. Hence, this thesis focuses primarily on the method of precise point positioning (PPP) by waiving linear combinations. The objective is the development of a universal PPP analysis approach for standalone PPP and network solutions. Raw observations conserve the physical properties of original observation. This allows a detailed analysis of individual signal characteristics, but leads to the necessity of handling them. The utilisation of raw observations comes along with maximum flexibility. It allows for the application of physical error models as well as individual weighting and edition of all individual observation types. The possibility of a joint processing of all observations and the estimation of all parameters in a single run results in a significant simplification of the processing procedure.
The first part of the thesis provides a general introduction to conventional GNSS analysis and highlights the limitations thereof. The second part introduces the technique of raw observations processing. It highlights the differences from the common ionosphere free processing approach and discusses the challenges. The concept presented for the analysis of GNSS raw observations is flexible and adjustable to any kind of GNSS application. This flexibility is attributed to a variety of different possible interpretations of the raw observation equation. In the frame of this thesis, a selection of different interpretations is introduced and demonstrated. One of the most important parameters for the analysis of raw observations is the so-called uncalibrated signal delays. The work presented exemplarily demonstrates their characteristics and discusses their implications for the analysis.
For maximum stability of the results, it is common practice to resolve and apply integer carrier phase ambiguities. The presented work discusses and demonstrates the feasibility of this methodology for the implemented approach. It shows that the new approach simplifies the resolution of inter-GNSS carrier phase ambiguities and extends the spectrum of resolvable ambiguities.
It is demonstrated that the proposed concept provides an “at least” equivalent alternative to the common processing strategies, applicable for highly precise standalone, as well as network PPP solutions, allowing for the simplified, consistent processing of different numbers of observation, suitable for an optimal, flexible, equivalent, joint processing of arbitrary GNSS observation types. It introduces a new dimension of analysis, with direct access to all individual observations and parameters.Note de contenu : 1 Introduction
1.1 Objectives of the research
1.2 External reference solutions
1.3 Outline of this thesis
2 Principles of Global Navigation Satellite Systems
2.1 General architecture
2.2 Geodetic reference systems and timescales
2.3 Navigation signals
3 Conventional GNSS analysis
3.1 Receiver system
3.2 GNSS observation modelling
3.3 Parameter estimation
3.4 Resolution of carrier phase ambiguities
4 Analysis of raw GNSS observations
4.1 Benefits of raw observation analyses
4.2 Challenges of raw observation analyses
4.3 Ambiguity resolution for raw observations
5 Implementation and general processing strategy
5.1 Software implementation
5.2 GNSS processing strategy applied
5.3 Parameter estimation setup
5.4 Observation weighting and screening criteria
6 Analysis of uncalibrated signal delays
6.1 Receiver-dependent signal delays
6.2 Satellite-related signal delays
6.3 Summary of analyses of uncalibrated signal delays
7 Applicability of raw observation processing
7.1 Applicability for global networks
7.2 Applicability for standalone PPP
7.3 Optimisation via bias calibration and ambiguity resolution
8 Conclusions
8.1 Challenges of raw observation analysis
8.2 Benefits and capabilities of raw observation analysis
8.3 Ambiguity fixing in the case of raw observations
8.4 Experiments and analyses
8.5 Future workNuméro de notice : 14900 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère Note de thèse : PhD : Fachbereich Bau- und Umweltingenieurwissenschaften : Technische Universität Darmstadt : 2014 DOI : sans En ligne : http://tuprints.ulb.tu-darmstadt.de/3843/7/Schoenemann_Dissertation_TUD.pdf Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76785 Documents numériques
en open access
14900 these 2014 SchnemannAdobe Acrobat PDF Precise position determination using a Galileo E5 single-frequency receiver / H. Toho Diessongo in GPS solutions, vol 18 n° 1 (january 2014)PermalinkPrecise point positioning with GPS: A new approach for positioning, atmospheric studies, and signal analysis / Rodrigo Figueiredo Leandro (2009)PermalinkStudy of external path delay correction techniques for high accuracy height determination with GPS / Olivier Bock in Physics and chemistry of the Earth, Part A: Solid Earth and Geodesy, vol 26 n° 3 ([01/03/2001])Permalink