Descripteur
Documents disponibles dans cette catégorie (87)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
Carrier phase bias estimation of geometry-free linear combination of GNSS signals for ionospheric TEC modeling / Anna Krypiak-Gregorczyk in GPS solutions, vol 22 n° 2 (April 2018)
[article]
Titre : Carrier phase bias estimation of geometry-free linear combination of GNSS signals for ionospheric TEC modeling Type de document : Article/Communication Auteurs : Anna Krypiak-Gregorczyk, Auteur ; Pawel Wielgosz, Auteur Année de publication : 2018 Article en page(s) : pp 22 - 45 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] combinaison linéaire
[Termes IGN] erreur systématique
[Termes IGN] modèle ionosphérique
[Termes IGN] phase
[Termes IGN] positionnement par GNSS
[Termes IGN] retard ionosphèrique
[Termes IGN] signal GNSS
[Termes IGN] teneur totale en électrons
[Vedettes matières IGN] Traitement de données GNSSRésumé : (Auteur) The ionosphere can be modeled and studied using multi-frequency GNSS signals and their geometry-free linear combination. Therefore, a number of GNSS-derived ionospheric models have been developed and applied in a broad range of applications. However, due to the complexity of estimating the carrier phase ambiguities, most of these models are based on low-accuracy carrier phase smoothed pseudorange data. This, in turn, critically limits their accuracy and applicability. Therefore, we present a new methodology of estimating the phase bias of the scaled L1 and L2 carrier phase difference which is a function of the ambiguities, the ionospheric delay, and hardware delays. This methodology is suitable for ionospheric modeling at regional and continental scales. In addition, we present its evaluation under varying ionospheric conditions. The test results show that the carrier phase bias of geometry-free linear combination can be estimated with a very high accuracy, which consequently allows for calculating ionospheric TEC with the uncertainty lower than 1.0 TECU. This high accuracy makes the resulting ionosphere model suitable for improving GNSS positioning for high-precision applications in geosciences. Numéro de notice : A2018-160 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-018-0711-4 Date de publication en ligne : 16/02/2018 En ligne : https://doi.org/10.1007/s10291-018-0711-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89783
in GPS solutions > vol 22 n° 2 (April 2018) . - pp 22 - 45[article]Characterizing noise in daily GPS position time series with overlapping Hadamard variance and maximum likelihood estimation / Chang Xu in Survey review, vol 49 n° 355 (October 2017)
[article]
Titre : Characterizing noise in daily GPS position time series with overlapping Hadamard variance and maximum likelihood estimation Type de document : Article/Communication Auteurs : Chang Xu, Auteur ; D. Yue, Auteur Année de publication : 2017 Article en page(s) : pp 239 - 248 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] bruit (théorie du signal)
[Termes IGN] bruit blanc
[Termes IGN] bruit rose
[Termes IGN] caractérisation
[Termes IGN] Chine
[Termes IGN] coordonnées GPS
[Termes IGN] latitude
[Termes IGN] méthode du maximum de vraisemblance (estimation)
[Termes IGN] série temporelle
[Termes IGN] signal aléatoire
[Termes IGN] station permanente
[Termes IGN] variance
[Termes IGN] variance de Hadamard
[Vedettes matières IGN] Traitement de données GNSSRésumé : (Auteur) We assess the noise characteristics of daily position time series (Jet Propulsion Laboratory global solutions) from 12 International GNSS Service sites located in China, using both overlapping Hadamard variance (OHVAR) and maximum likelihood estimation (MLE). The result shows that OHVAR is computationally cheap, and the dominate power-law noise inferred is in good agreement with the ones inferred by comparing MLE values. However, OHVAR is insufficient to assess the long-period noise characteristics [e.g., random walk noise (RW)]. From the MLE analysis, the RW contribution is likely to be present in 14% of the time series, while the noise of most sites are characterized by a combination of white and flicker (or power law) noise (i.e., FL + WH or PL + WH). Moreover, sites near the northern crest of the equatorial ionization anomaly have larger amplitudes of WH in the vertical component, while no clear latitude dependency is observed in FL amplitudes. Numéro de notice : A2017-547 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/00396265.2016.1163830 En ligne : https://doi.org/10.1080/00396265.2016.1163830 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86602
in Survey review > vol 49 n° 355 (October 2017) . - pp 239 - 248[article]Periodic signals in a pseudo-kinematic GPS coordinate time series depending on the antenna phase centre model – TRM55971.00 TZGD antenna case study / Karol Dawidowicz in Survey review, vol 49 n° 355 (October 2017)
[article]
Titre : Periodic signals in a pseudo-kinematic GPS coordinate time series depending on the antenna phase centre model – TRM55971.00 TZGD antenna case study Type de document : Article/Communication Auteurs : Karol Dawidowicz, Auteur Année de publication : 2017 Article en page(s) : pp 268 - 276 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] antenne GNSS
[Termes IGN] centre de phase
[Termes IGN] étalonnage des données
[Termes IGN] GPS en mode pseudo-cinématique
[Termes IGN] Pologne
[Termes IGN] série temporelle
[Termes IGN] station permanente
[Vedettes matières IGN] Traitement de données GNSSRésumé : (Auteur) This study investigates the differences between position estimates obtained using individual and type-mean (igs08.atx) antenna calibration models in GPS pseudo-kinematic processing. We used 15-min observation windows to study the short-period oscillations. Continuous GPS observations from eight selected Polish EUREF Permanent Network stations with the same TRM55971.00 TZGD antenna were used. The results showed that the differences in the calibration models, directly propagate into the position domain, affecting sub-daily results and influencing periodic variations. The sub-daily variations have periods close to half a sidereal day with amplitudes of up to 10 mm in position components. It could also be demonstrated that the mean position offsets, resulting from the use of individual calibrations instead of type-mean igs08.atx calibrations, can reach up to 5 mm in the up component, while the offsets in the horizontal components generally remain below 1 mm. Numéro de notice : A2017-550 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/00396265.2016.1166688 En ligne : https://doi.org/10.1080/00396265.2016.1166688 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86606
in Survey review > vol 49 n° 355 (October 2017) . - pp 268 - 276[article]ERTK: extra-wide-lane RTK of triple-frequency GNSS signals / Bofeng Li in Journal of geodesy, vol 91 n° 9 (September 2017)
[article]
Titre : ERTK: extra-wide-lane RTK of triple-frequency GNSS signals Type de document : Article/Communication Auteurs : Bofeng Li, Auteur ; Zhen Li, Auteur ; Zhiteng Zhang, Auteur ; Yu’an Tan, Auteur Année de publication : 2017 Article en page(s) : pp 1031 – 1047 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse comparative
[Termes IGN] données BeiDou
[Termes IGN] données Galileo
[Termes IGN] filtrage du signal
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] précision centimétrique
[Termes IGN] propagation ionosphérique
[Termes IGN] récepteur trifréquence
[Termes IGN] résolution d'ambiguïté
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) Triple-frequency signals have thus far been available for all satellites of BeiDou and Galileo systems and for some GPS satellites. The main benefit of triple-frequency signals is their formation of extra-wide-lane (EWL) combinations whose ambiguities can be instantaneously fixed for several 10–100 km baselines. Yet, this benefit has not been fully exploited and only used as a constraint for narrow-lane (NL) ambiguity resolution (AR) in most previous studies. In this study, we comprehensively investigate the real-time kinematic (RTK) capabilities of EWL observations, also referred to as EWL RTK (ERTK). We begin by mathematically expressing the ease of EWL AR and the difficulty of NL AR, respectively, using a numerical demonstration. We then present the mathematical models for ERTK including the ionosphere-ignored, ionosphere-float and ionosphere-smoothed types. The experiments are conducted using a four-station network of real triple-frequency BeiDou data with baseline lengths from 33 to 75 km. The results show that the ionosphere-ignored ERTK achieves real-time solutions with a horizontal accuracy of about 10 cm. Although the ionosphere-float ERTK solutions are very noisy, they can be quickly improved at the centimetre level by further applying the ionosphere-smoothed model. Note that such accurate results are very promising and already satisfy many applications without complicated NL AR. To the best of our knowledge, this is the first comprehensive study to make full use of EWL observations of triple-frequency signals on RTK. Numéro de notice : A2017-464 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1006-1 En ligne : https://doi.org/10.1007/s00190-017-1006-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86410
in Journal of geodesy > vol 91 n° 9 (September 2017) . - pp 1031 – 1047[article]Improving BeiDou real-time precise point positioning with numerical weather models / Cuixian Lu in Journal of geodesy, vol 91 n° 9 (September 2017)
[article]
Titre : Improving BeiDou real-time precise point positioning with numerical weather models Type de document : Article/Communication Auteurs : Cuixian Lu, Auteur ; Xingxing Li, Auteur ; Florian Zus, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 1019–1029 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] données BeiDou
[Termes IGN] données météorologiques
[Termes IGN] positionnement ponctuel précis
[Termes IGN] précision du positionnement
[Termes IGN] retard troposphérique
[Termes IGN] temps réel
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) Precise positioning with the current Chinese BeiDou Navigation Satellite System is proven to be of comparable accuracy to the Global Positioning System, which is at centimeter level for the horizontal components and sub-decimeter level for the vertical component. But the BeiDou precise point positioning (PPP) shows its limitation in requiring a relatively long convergence time. In this study, we develop a numerical weather model (NWM) augmented PPP processing algorithm to improve BeiDou precise positioning. Tropospheric delay parameters, i.e., zenith delays, mapping functions, and horizontal delay gradients, derived from short-range forecasts from the Global Forecast System of the National Centers for Environmental Prediction (NCEP) are applied into BeiDou real-time PPP. Observational data from stations that are capable of tracking the BeiDou constellation from the International GNSS Service (IGS) Multi-GNSS Experiments network are processed, with the introduced NWM-augmented PPP and the standard PPP processing. The accuracy of tropospheric delays derived from NCEP is assessed against with the IGS final tropospheric delay products. The positioning results show that an improvement in convergence time up to 60.0 and 66.7% for the east and vertical components, respectively, can be achieved with the NWM-augmented PPP solution compared to the standard PPP solutions, while only slight improvement in the solution convergence can be found for the north component. A positioning accuracy of 5.7 and 5.9 cm for the east component is achieved with the standard PPP that estimates gradients and the one that estimates no gradients, respectively, in comparison to 3.5 cm of the NWM-augmented PPP, showing an improvement of 38.6 and 40.1%. Compared to the accuracy of 3.7 and 4.1 cm for the north component derived from the two standard PPP solutions, the one of the NWM-augmented PPP solution is improved to 2.0 cm, by about 45.9 and 51.2%. The positioning accuracy for the up component improves from 11.4 and 13.2 cm with the two standard PPP solutions to 8.0 cm with the NWM-augmented PPP solution, an improvement of 29.8 and 39.4%, respectively. Numéro de notice : A2017-463 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1005-2 En ligne : https://doi.org/10.1007/s00190-017-1005-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86409
in Journal of geodesy > vol 91 n° 9 (September 2017) . - pp 1019–1029[article]Performance evaluation of ionospheric time delay forecasting models using GPS observations at a low-latitude station / G. Sivavaraprasad in Advances in space research, vol 60 n° 2 (15 July 2017)PermalinkMultipath detection based on single orthogonal dual linear polarized GNSS antenna / Ke Zhang in GPS solutions, vol 21 n° 3 (July 2017)PermalinkAn example and analysis for ambiguity resolution in the indoor ZigBee positioning system / Joanna Janicka in Reports on geodesy and geoinformatics, vol 103 n° 1 (June 2017)PermalinkGPS code phase variations (CPV) for GNSS receiver antennas and their effect on geodetic parameters and ambiguity resolution / Tobias Kersten in Journal of geodesy, vol 91 n° 6 (June 2017)PermalinkMultivariate analysis of GPS position time series of JPL second reprocessing campaign / Ali Reza Amiri-Simkooei in Journal of geodesy, vol 91 n° 6 (June 2017)PermalinkIntegrating uncertainty propagation in GNSS radio occultation retrieval: From bending angle to dry-air atmospheric profiles / Jakob Schwarz in Earth and space science, vol 4 n° 4 (April 2017)PermalinkIonospheric error contribution to GNSS single-frequency navigation at the 2014 solar maximum / Raul Orus Perez in Journal of geodesy, vol 91 n° 4 (April 2017)PermalinkRapid PPP ambiguity resolution using GPS+GLONASS observations / Yanyan Liu in Journal of geodesy, vol 91 n° 4 (April 2017)PermalinkMulti-GNSS precise point positioning (MGPPP) using raw observations / Teng Liu in Journal of geodesy, vol 91 n° 3 (March 2017)PermalinkStudy of the effects on GPS coordinate time series caused by higher-order ionospheric corrections calculated using the DIPOLE model / Liansheng Deng in Geodesy and Geodynamics, vol 8 n° 2 (March 2017)Permalink