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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
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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)
[article]
Titre : Precise position determination using a Galileo E5 single-frequency receiver Type de document : Article/Communication Auteurs : H. Toho Diessongo, Auteur ; Torben Schüler, Auteur ; Stefan Junker, Auteur Année de publication : 2014 Article en page(s) : pp 73 - 83 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] code GNSS
[Termes IGN] positionnement par Galileo
[Termes IGN] positionnement ponctuel précis
[Termes IGN] résolution d'ambiguïté
[Termes IGN] retard ionosphèrique
[Termes IGN] signal GalileoRésumé : (auteur) The European Galileo system offers one dedicated signal that is superior to all other signals currently available in space, namely the broadband signal E5. This signal has a bandwidth of at least 51 MHz using an AltBOC modulation. It features a code range noise at centimeter level. Additionally, the impact of multipath effects on this signal is significantly lower compared to all other available GNSS signals. These unique features of Galileo E5 drastically improve the precision of code range measurements and hence enable precise single-frequency positioning. Certain scientific and non-scientific applications in the positioning domain could likely benefit from the exploitation of E5 measurements. A positioning approach based on an additive combination of code range and carrier phase measurements (CPC—“code-plus-carrier”) to eliminate the ionospheric delay could be used to perform precise positioning over long distances. Unfortunately, this derived observable contains the ambiguity term as an additional unknown what normally requires longer observation windows in order to allow sufficient convergence of the ambiguity parameters. For this reason, a rapid convergence algorithm based on Kalman filtering was implemented in addition to the conventional CPC approach that is also discussed. The CPC-based results yield a positioning precision of 2–5 cm after a convergence time of about 3 h. The rapid convergence filter allows fixing the ambiguity terms within a few minutes, and the obtained position results are at the sub-decimeter level. Regarding one selected test, real data from Galileo experimental satellite GIOVE A were used in order to confirm our assumptions. However, since the current Galileo constellation is not sufficient for real-world positioning trials yet, all major results are based on simulated data. Numéro de notice : A2014-655 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-013-0311-2 En ligne : https://doi.org/10.1007/s10291-013-0311-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77826
in GPS solutions > vol 18 n° 1 (january 2014) . - pp 73 - 83[article]Assessment of correct fixing rate for precise point positioning ambiguity resolution on a global scale / Xiaohong Zhang in Journal of geodesy, vol 87 n° 6 (June 2013)
[article]
Titre : Assessment of correct fixing rate for precise point positioning ambiguity resolution on a global scale Type de document : Article/Communication Auteurs : Xiaohong Zhang, Auteur ; Pan Li, Auteur Année de publication : 2013 Article en page(s) : pp 579 - 589 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] dégradation du signal
[Termes IGN] données GPS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] propagation ionosphérique
[Termes IGN] résolution d'ambiguïté
[Termes IGN] simple différence
[Termes IGN] variance de phaseRésumé : (Auteur) Ambiguity resolution (AR) for a single receiver has been a popular topic in Global Positioning System (GPS) recently. Ambiguity-resolution methods for precise point positioning (PPP) have been well documented in recent years, demonstrating that it can improve the accuracy of PPP. However, users are often concerned about the reliability of ambiguity-fixed PPP solution in practical applications. If ambiguities are fixed to wrong integers, large errors would be introduced into position estimates. In this paper, we aim to assess the correct fixing rate (CFR), i.e., number of ambiguities correctly fixing to the total number of ambiguities correctly and incorrectly fixing, for PPP user ambiguity resolution on a global scale. A practical procedure is presented to evaluate the CFR of PPP user ambiguity resolution. GPS data of the first 3 days in each month of 2010 from about 390 IGS stations are used for experiments. Firstly, we use GPS data collected from about 320 IGS stations to estimate global single-differenced (SD) wide-lane and narrow-lane satellite uncalibrated phase delays (UPDs). The quality of UPDs is evaluated. We found that wide-lane UPD estimates have a rather small standard deviation (Std) between 0.003 and 0.004 cycles while most of Std of narrow-lane estimates are from 0.01 to 0.02 cycles. Secondly, many experiments have been conducted to investigate the CFR of integer ambiguity resolution we can achieve under different conditions, including reference station density, observation session length and the ionospheric activity. The results show that the CFR of PPP can exceed 98.0 % with only 1 h of observations for most user stations. No obvious correlation between the CFR and the reference station density is found. Therefore, nearly homogeneous CFR can be achieved in PPP AR for global users. At user end, higher CFR could be achieved with longer observations. The average CFR for 30-min, 1-h, 2-h and 4-h observation is 92.3, 98.2, 99.5 and 99.7 %, respectively. In order to get acceptable CFR, 1 h is a recommended minimum observation time. Furthermore, the CFR of PPP can be affected by diurnal variation and geomagnetic latitude variation in the ionosphere. During one day at the hours when rapid ionospheric variations occur or in low geomagnetic latitude regions where equatorial electron density irregularities are produced relatively frequently, a significant degradation of the CFR is demonstrated. Numéro de notice : A2013-341 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-013-0632-5 Date de publication en ligne : 23/03/2013 En ligne : https://doi.org/10.1007/s00190-013-0632-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32479
in Journal of geodesy > vol 87 n° 6 (June 2013) . - pp 579 - 589[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 266-2013061 SL Revue Centre de documentation Revues en salle Disponible A method for improving uncalibrated phase delay estimation and ambiguity-fixing in real-time precise point positioning / Xinging Li in Journal of geodesy, vol 87 n° 5 (May 2013)
[article]
Titre : A method for improving uncalibrated phase delay estimation and ambiguity-fixing in real-time precise point positioning Type de document : Article/Communication Auteurs : Xinging Li, Auteur ; Maorong Ge, Auteur Année de publication : 2013 Article en page(s) : pp 405 - 416 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] ambiguïté entière
[Termes IGN] atténuation du signal
[Termes IGN] mesurage de phase
[Termes IGN] positionnement ponctuel précis
[Termes IGN] propagation ionosphérique
[Termes IGN] résolution d'ambiguïté
[Termes IGN] temps de propagation
[Termes IGN] temps réelRésumé : (Auteur) In order to improve the performance of precise point positioning (PPP), this paper presents a new data processing scheme to shorten the convergence time and the observation time required for a reliable ambiguity-fixing. In the new scheme, L1 and L2 raw observations are used and the slant ionospheric delays are treated as unknown parameters. The empirical spatial and temporal constraints and the ionospheric delays derived from a real-time available ionospheric model are all considered as pseudo-observations into the estimation for strengthening the solution. Furthermore, we develop a real-time computational procedure for generating uncalibrated phase delays (UPDs) on L1 and L2 frequencies. The PPP solution is first carried out on all reference stations based on the proposed scheme, undifferenced float ambiguities on L1 and L2 frequencies can be directly obtained from the new scheme. The L1 and L2 UPDs are then generated and broadcasted to users in real-time. This data product and also the performance of the new PPP scheme are evaluated. Our results indicate that the new processing scheme considering ionospheric characteristics can reduce the convergence time by about 30 % for float kinematic solutions. The observation time for a reliable ambiguity-fixing is shortened by 25 % compared to that of the traditional ambiguity-fixed kinematic solution. When the new method is used for static reference stations, the observation time for ambiguity-fixing is about 10 min in static mode and only 5 min if the coordinates are fixed to well-known values. Numéro de notice : A2013-251 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-013-0611-x En ligne : https://doi.org/10.1007/s00190-013-0611-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32389
in Journal of geodesy > vol 87 n° 5 (May 2013) . - pp 405 - 416[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 266-2013051 SL Revue Centre de documentation Revues en salle Disponible Mitigating the impact of ionospheric cycle slips in GNSS observations / Simon Banville in Journal of geodesy, vol 87 n° 2 (February 2013)
[article]
Titre : Mitigating the impact of ionospheric cycle slips in GNSS observations Type de document : Article/Communication Auteurs : Simon Banville, Auteur ; R. Langley, Auteur Année de publication : 2013 Article en page(s) : pp 179 - 193 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] Canada
[Termes IGN] données GNSS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] propagation ionosphérique
[Termes IGN] scintillation
[Termes IGN] traitement de données GNSSRésumé : (Auteur) Processing of data from global navigation satellite systems (GNSS), such as GPS, GLONASS and Galileo, can be considerably impeded by disturbances in the ionosphere. Cycle-slip detection and correction thus becomes a crucial component of robust software. Still, dealing with ionospheric cycle slips is not trivial due to scintillation effects in both the phase and the amplitude of the signals. In this contribution, a geometry-based approach with rigorous handling of the ionosphere is presented. A detailed analysis of the cycle-slip correction process is also tackled by examining its dependence on phase and code noise, non-dispersive effects and, of course, the ionosphere. The importance of stochastic modeling in validating the integer cycle-slip candidates is emphasized and illustrated through simulations. By examining the relationship between ionospheric bias and ionospheric constraint, it is shown that there is a limit in the magnitude of ionospheric delay variation that can be handled by the cycle-slip correction process. Those concepts are applied to GNSS data collected by stations in northern Canada, and show that enhanced cycle-slip detection can lead to decimeter-level improvements in the accuracy of kinematic PPP solutions with a 30-s sampling interval. Cycle-slip correction associated with ionospheric delay variations exceeding 50 cm is also demonstrated, although there are risks with such a procedure and these are pointed out. Numéro de notice : A2013-100 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-012-0604-1 Date de publication en ligne : 04/11/2012 En ligne : https://doi.org/10.1007/s00190-012-0604-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32238
in Journal of geodesy > vol 87 n° 2 (February 2013) . - pp 179 - 193[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 266-2013021 SL Revue Centre de documentation Revues en salle Disponible Single-receiver single-channel multi-frequency GNSS integrity: outliers, slips, and ionospheric disturbances / Peter J.G. Teunissen in Journal of geodesy, vol 87 n° 2 (February 2013)PermalinkApport du système de navigation GLONASS à la surveillance de l'ionosphère au dessus de l'Europe / Emilie Pelletier (2013)PermalinkMesures GNSS et retard troposphérique / Franck Verrouil (2013)Permalink3D coseismic displacement of 2010 Darfield, New Zealand earthquake estimated from multi-aperture InSAR and D-InSAR measurements / J. Hu in Journal of geodesy, vol 86 n° 11 (November 2012)PermalinkSpace weather and the Australian ionospheric prediction service: ready for the Solar Max 2012 / Dave Neudegg in Space research today, n° 184 (01/08/2012)PermalinkIonospheric artifacts in simultaneous L-band InSAR and GPS observations / J. Chen in IEEE Transactions on geoscience and remote sensing, vol 50 n° 4 (April 2012)PermalinkGalileo, un système global de positionnement par satellites / Jonathan Chenal (2012)PermalinkAccuracy assessment of the GPS-TEC calibration constants by means of a simulation technique / Jacques Conte in Journal of geodesy, vol 85 n° 10 (October 2011)PermalinkSimulation study of the influence of the ionospheric layer height in the thin layer ionospheric model / C. Brunini in Journal of geodesy, vol 85 n° 9 (September 2011)PermalinkRapid re-convergences to ambiguity-fixed solutions in precise point positioning / J. Geng in Journal of geodesy, vol 84 n° 12 (December 2010)Permalink