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GPS receiver phase biases estimable in PPP-RTK networks : dynamic characterization and impact analysis / Baocheng Zhang in Journal of geodesy, vol 92 n° 6 (June 2018)
[article]
Titre : GPS receiver phase biases estimable in PPP-RTK networks : dynamic characterization and impact analysis Type de document : Article/Communication Auteurs : Baocheng Zhang, Auteur ; Teng Liu, Auteur ; Yunbin Yuan, Auteur Année de publication : 2018 Article en page(s) : pp 659 – 674 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] caractérisation
[Termes IGN] données GPS
[Termes IGN] erreur systématique
[Termes IGN] filtre de Kalman
[Termes IGN] filtre passe-bas
[Termes IGN] GPS en mode cinématique
[Termes IGN] impact sur les données
[Termes IGN] phase GPS
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] positionnement ponctuel précis
[Termes IGN] récepteur bifréquenceRésumé : (Auteur) The integer ambiguity resolution enabled precise point positioning (PPP-RTK) has been proven advantageous in a wide range of applications. The realization of PPP-RTK concerns the isolation of satellite phase biases (SPBs) and other corrections from a network of Global Positioning System (GPS) reference receivers. This is generally based on Kalman filter in order to achieve real-time capability, in which proper modeling of the dynamics of various types of unknowns remains crucial. This paper seeks to gain insight into how to reasonably deal with the dynamic behavior of the estimable receiver phase biases (RPBs). Using dual-frequency GPS data collected at six colocated receivers over days 50–120 of 2015, we analyze the 30-s epoch-by-epoch estimates of L1 and wide-lane (WL) RPBs for each receiver pair. The dynamics observed in these estimates are a combined effect of three factors, namely the random measurement noise, the multipath and the ambient temperature. The first factor can be overcome by turning to a real-time filter and the second by considering the use of a sidereal filtering. The third factor has an effect only on the WL, and this effect appears to be linear. After accounting for these three factors, the low-pass-filtered, sidereal-filtered, epoch-by-epoch estimates of L1 RPBs follow a random walk process, whereas those of WL RPBs are constant over time. Properly modeling the dynamics of RPBs is vital, as it ensures the best convergence of the Kalman-filtered, between-satellite single-differenced SPB estimates to their correct values and, in turn, shortens the time-to-first-fix at user side. Numéro de notice : A2018-151 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1085-z Date de publication en ligne : 13/11/2017 En ligne : https://doi.org/10.1007/s00190-017-1085-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89764
in Journal of geodesy > vol 92 n° 6 (June 2018) . - pp 659 – 674[article]Influences of environmental loading corrections on the nonlinear variations and velocity uncertainties for the reprocessed global positioning system height time series of the crustal movement observation network of China / Peng Yuan in Remote sensing, vol 10 n° 6 (June 2018)
[article]
Titre : Influences of environmental loading corrections on the nonlinear variations and velocity uncertainties for the reprocessed global positioning system height time series of the crustal movement observation network of China Type de document : Article/Communication Auteurs : Peng Yuan, Auteur ; Zhao Li, Auteur ; Weiping Jiang, Auteur ; Yifang Ma , Auteur ; Wu Chen, Auteur ; Nico Sneeuw, Auteur Année de publication : 2018 Projets : 1-Pas de projet / Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] analyse en composantes principales
[Termes IGN] champ de vitesse
[Termes IGN] Chine
[Termes IGN] coordonnées GPS
[Termes IGN] correction géométrique
[Termes IGN] données GPS
[Termes IGN] réseau de surveillance géophysique
[Termes IGN] série temporelle
[Termes IGN] station permanenteRésumé : (auteur) Mass redistribution of the atmosphere, oceans, and terrestrial water storage generates crustal displacements which can be predicted by environmental loading models and observed by the Global Positioning System (GPS). In this paper, daily height time series of 235 GPS stations derived from a homogeneously reprocessed Crustal Movement Observation Network of China (CMONOC) and corresponding loading displacements predicted by the Deutsche GeoForschungsZentrum (GFZ) are compared to assess the effects of loading corrections on the nonlinear variations of GPS time series. Results show that the average root mean square (RMS) of vertical displacements due to atmospheric, nontidal oceanic, hydrological, and their combined effects are 3.2, 0.6, 2.7, and 4.0 mm, respectively. Vertical annual signals of loading and GPS are consistent in amplitude but different in phase systematically. The average correlation coefficient between loading and GPS height time series is 0.6. RMS of the GPS height time series are reduced by 20% on average. Moreover, an investigation of 208 CMONOC stations with observing time spans of ~4.6 years shows that environmental loading corrections lead to an overestimation of the GPS velocity uncertainty by about 1.4 times on average. Nevertheless, by using a common mode component filter through principal component analysis, the dilution of velocity precision due to environmental loading corrections can be compensated. Numéro de notice : A2018-658 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/rs10060958 Date de publication en ligne : 15/06/2018 En ligne : https://doi.org/10.3390/rs10060958 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93811
in Remote sensing > vol 10 n° 6 (June 2018)[article]Documents numériques
en open access
Influences of environmental loading corrections ... - pdf éditeurAdobe Acrobat PDF Comparison of total water vapour content in the Arctic derived from GNSS, AIRS, MODIS and SCIAMACHY / Dunya Alraddawi in Atmospheric measurement techniques, vol 11 n° 5 (May 2018)
[article]
Titre : Comparison of total water vapour content in the Arctic derived from GNSS, AIRS, MODIS and SCIAMACHY Type de document : Article/Communication Auteurs : Dunya Alraddawi, Auteur ; Alain Sarkissian, Auteur ; Philippe Keckhut, Auteur ; Olivier Bock , Auteur ; Stefan Noël, Auteur ; Slimane Bekki, Auteur ; Abdanour Irbah, Auteur ; Mustapha Meftah, Auteur ; Chantal Claud, Auteur Année de publication : 2018 Projets : GNSS4SWEC / , VEGAN / Bock, Olivier Article en page(s) : pp 2949 - 2965 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] analyse comparative
[Termes IGN] Arctique
[Termes IGN] Atmospheric Infrared Sounder
[Termes IGN] données GNSS
[Termes IGN] données météorologiques
[Termes IGN] erreur systématique
[Termes IGN] image Aqua-MODIS
[Termes IGN] image Terra-MODIS
[Termes IGN] nébulosité
[Termes IGN] série temporelle
[Termes IGN] teneur en vapeur d'eauRésumé : (auteur) Atmospheric water vapour plays a key role in the Arctic radiation budget, hydrological cycle and hence climate, but its measurement with high accuracy remains an important challenge. Total column water vapour (TCWV) datasets derived from ground-based GNSS measurements are used to assess the quality of different existing satellite TCWV datasets, namely from the Moderate Resolution Imaging Spectroradiometer (MODIS), the Atmospheric Infrared Sounder (AIRS) and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY). The comparisons between GNSS and satellite data are carried out for three reference Arctic observation sites (Sodankylä, Ny-Ålesund and Thule) where long homogeneous GNSS time series of more than a decade (2001–2014) are available. We select hourly GNSS data that are coincident with overpasses of the different satellites over the three sites and then average them into monthly means that are compared with monthly mean satellite products for different seasons. The agreement between GNSS and satellite time series is generally within 5 % at all sites for most conditions. The weakest correlations are found during summer. Among all the satellite data, AIRS shows the best agreement with GNSS time series, though AIRS TCWV is often slightly too high in drier atmospheres (i.e. high-latitude stations during autumn and winter). SCIAMACHY TCWV data are generally drier than GNSS measurements at all the stations during the summer. This study suggests that these biases are associated with cloud cover, especially at Ny-Ålesund and Thule. The dry biases of MODIS and SCIAMACHY observations are most pronounced at Sodankylä during the snow season (from October to March). Regarding SCIAMACHY, this bias is possibly linked to the fact that the SCIAMACHY TCWV retrieval does not take accurately into account the variations in surface albedo, notably in the presence of snow with a nearby canopy as in Sodankylä. The MODIS bias at Sodankylä is found to be correlated with cloud cover fraction and is also expected to be affected by other atmospheric or surface albedo changes linked for instance to the presence of forests or anthropogenic emissions. Overall, the results point out that a better estimation of seasonally dependent surface albedo and a better consideration of vertically resolved cloud cover are recommended if biases in satellite measurements are to be reduced in the polar regions. Numéro de notice : A2018-240 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.5194/amt-11-2949-2018 Date de publication en ligne : 18/05/2018 En ligne : https://doi.org/10.5194/amt-11-2949-2018 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90215
in Atmospheric measurement techniques > vol 11 n° 5 (May 2018) . - pp 2949 - 2965[article]Constraints on transient viscoelastic rheology of the asthenosphere from seasonal deformation / Kristel Chanard in Geophysical research letters, vol 45 n° 5 (15 March 2018)
[article]
Titre : Constraints on transient viscoelastic rheology of the asthenosphere from seasonal deformation Type de document : Article/Communication Auteurs : Kristel Chanard , Auteur ; Luce Fleitout, Auteur ; Eric Calais, Auteur ; Sylvain Barbot, Auteur ; Jean-Philippe Avouac, Auteur Année de publication : 2018 Projets : 3-projet - voir note / Bock, Olivier Article en page(s) : pp 2328 - 2338 Note générale : bibliographie
This work was partially supported by NSF grant EAR-1345136, the Laboratorie de Recherche Commun “Yves Rocard” (ENS-CEA-CNRS), and CNRS/TOSCA grant 2925.Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] déformation de la croute terrestre
[Termes IGN] données GNSS
[Termes IGN] données GRACE
[Termes IGN] fonction de Green
[Termes IGN] rhéologie
[Termes IGN] viscositéRésumé : (auteur) We discuss the constraints on short‐term asthenospheric viscosity provided by seasonal deformation of the Earth. We use data from 195 globally distributed continuous Global Navigation Satellite System stations. Surface loading is derived from the Gravity Recovery and Climate Experiment and used as an input to predict geodetic displacements. We compute Green's functions for surface displacements for a purely elastic spherical reference Earth model and for viscoelastic Earth models. We show that a range of transient viscoelastic rheologies derived to explain the early phase of postseismic deformation may induce a detectable effect on the phase and amplitude of horizontal displacements induced by seasonal loading at long wavelengths (1,300–4,000 km). By comparing predicted and observed seasonal horizontal motion, we conclude that transient asthenospheric viscosity cannot be lower than 5 × 1017 Pa.s, suggesting that low values of transient asthenospheric viscosities reported in some postseismic studies cannot hold for the seasonal deformation global average. Numéro de notice : A2018-654 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1002/2017GL076451 Date de publication en ligne : 12/02/2018 En ligne : https://doi.org/10.1002/2017GL076451 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93514
in Geophysical research letters > vol 45 n° 5 (15 March 2018) . - pp 2328 - 2338[article]Kinematic-PPP using single/dual frequency observations from (GPS, GLONASS and GPS/GLONASS) constellations for hydrography / Ashraf Farah in Artificial satellites, vol 53 n° 1 (March 2018)
[article]
Titre : Kinematic-PPP using single/dual frequency observations from (GPS, GLONASS and GPS/GLONASS) constellations for hydrography Type de document : Article/Communication Auteurs : Ashraf Farah, Auteur Année de publication : 2018 Article en page(s) : pp 37 - 46 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Assouan
[Termes IGN] données GLONASS
[Termes IGN] données GPS
[Termes IGN] Nil (fleuve)
[Termes IGN] positionnement cinématique
[Termes IGN] positionnement par GLONASS
[Termes IGN] positionnement par GPS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] récepteur bifréquence
[Termes IGN] récepteur monofréquenceRésumé : (auteur) Global Positioning System (GPS) technology is ideally suited for inshore and offshore positioning because of its high accuracy and the short observation time required for a position fix. Precise point positioning (PPP) is a technique used for position computation with a high accuracy using a single GNSS receiver. It relies on highly accurate satellite position and clock data that can be acquired from different sources such as the International GNSS Service (IGS). PPP precision varies based on positioning technique (static or kinematic), observations type (single or dual frequency) and the duration of observations among other factors. PPP offers comparable accuracy to differential GPS with safe in cost and time. For many years, PPP users depended on GPS (American system) which considered the solely reliable system. GLONASS's contribution in PPP techniques was limited due to fail in maintaining full constellation. Yet, GLONASS limited observations could be integrated into GPS-based PPP to improve availability and precision. As GLONASS reached its full constellation early 2013, there is a wide interest in PPP systems based on GLONASS only and independent of GPS. This paper investigates the performance of kinematic PPP solution for the hydrographic applications in the Nile river (Aswan, Egypt) based on GPS, GLONASS and GPS/GLONASS constellations. The study investigates also the effect of using two different observation types; single-frequency and dual frequency observations from the tested constellations. Numéro de notice : A2018-174 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.2478/arsa-2018-0004 Date de publication en ligne : 24/03/2018 En ligne : https://doi.org/10.2478/arsa-2018-0004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89814
in Artificial satellites > vol 53 n° 1 (March 2018) . - pp 37 - 46[article]An accurate Kriging-based regional ionospheric model using combined GPS/BeiDou observations / Mohamed Abdelazeem in Journal of applied geodesy, vol 12 n° 1 (January 2018)PermalinkAssessing data from permanent GNSS stations in Algeria / Hassen Abdellaoui in Bulletin des sciences géographiques, n° 31 (2017 - 2018)PermalinkCartographie des déformations de surface sur l’île de Taiwan par interférométrie RADAR Sentinel-1 / Miloud Fekaouni (2018)PermalinkPermalinkMise en évidence de l’activité récente des failles du bassin de Naryn (Kyrgyzstan) à partir de données photogrammétriques Pléiades et drone : un nouvel apport pour l’aléa sismique / Aurélie Médard (2018)PermalinkPermalinkNavigation des personnes aux moyens des technologies des smartphones et des données d’environnements cartographiés / Fadoua Taia Alaoui (2018)PermalinkQuality based approach for updating geographic authoritative datasets from crowdsourced GPS traces / Stefan Ivanovic (2018)PermalinkSurveillance des déformations des volcans avec des réseaux de Géocubes : expériences et leçons d’un déploiement sur l’Etna / Mohamed-Amjad Lasri (2018)PermalinkPerformance analysis of BDS/GPS precise point positioning with undifferenced ambiguity resolution / Min Wang in Advances in space research, vol 60 n° 12 (15 December 2017)Permalink