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Diagnostic study of a high‐precipitation event in the Western Mediterranean: adequacy of current operational networks / Samiro Khodayar in Quarterly Journal of the Royal Meteorological Society, vol 142 n° S1 (August 2016)
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Titre : Diagnostic study of a high‐precipitation event in the Western Mediterranean: adequacy of current operational networks Type de document : Article/Communication Auteurs : Samiro Khodayar, Auteur ; F. Raff, Auteur ; Norbert Kalthoff, Auteur ; Olivier Bock , Auteur
Année de publication : 2016 Article en page(s) : pp 72 - 85 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] climat méditerranéen
[Termes IGN] données météorologiques
[Termes IGN] inondation
[Termes IGN] littoral méditerranéen
[Termes IGN] modèle de simulation
[Termes IGN] positionnement par GPS
[Termes IGN] précipitation
[Termes IGN] teneur en vapeur d'eauRésumé : (auteur) To investigate whether the spatial and temporal resolution of current operational observing systems in the Western Mediterranean (WMed) region suffice to adequately represent the atmospheric processes responsible for the initiation and intensification of convection, a diagnostic study of the HyMex Intensive Observation Period 8 (IOP8) is performed. During the IOP8, heavy rainfall with intense lightning and consequent devastating flash floods occurred in the WMed region. The synergy of operational networks in the northern WMed, including Global Positioning System (GPS) stations, rain gauges, weather stations, lightning sensors and radiosondes, was used to document in detail the evolution of the heavy precipitation event. In general, the resolution of the aforementioned networks adequately sampled the temporal and spatial variability of the atmospheric water vapour, as well as the position of mesoscale convergence zones which played a key role in the initiation and evolution of convective systems in this case. Nevertheless, high uncertainty was associated with the existence and location of moisture convergence zones and wind convergence lines over the sea, reflecting the need for model analysis and remote‐sensing observations to complete the documentation of the event. Numéro de notice : A2016--195 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1002/qj.2600 Date de publication en ligne : 11/06/2015 En ligne : https://doi.org/10.1002/qj.2600 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91857
in Quarterly Journal of the Royal Meteorological Society > vol 142 n° S1 (August 2016) . - pp 72 - 85[article]Estimation of satellite antenna phase center offsets for Galileo / Peter Steigenberger in Journal of geodesy, vol 90 n° 8 (August 2016)
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Titre : Estimation of satellite antenna phase center offsets for Galileo Type de document : Article/Communication Auteurs : Peter Steigenberger, Auteur ; M. Fritsche, Auteur ; Rolf Dach, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : Pages 773 - 785 Note générale : bibliograohie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] antenne Galileo
[Termes IGN] centre de phase
[Termes IGN] compensation
[Termes IGN] orbitographie
[Termes IGN] positionnement par GNSS
[Termes IGN] signal Galileo
[Termes IGN] soleil (étoile)Résumé : (auteur) Satellite antenna phase center offsets for the Galileo In-Orbit Validation (IOV) and Full Operational Capability (FOC) satellites are estimated by two different analysis centers based on tracking data of a global GNSS network. The mean x- and y-offsets could be determined with a precision of a few centimeters. However, daily estimates of the x-offsets of the IOV satellites show pronounced systematic effects with a peak-to-peak amplitude of up to 70 cm that depend on the orbit model and the elevation of the Sun above the orbital plane. For the IOV y-offsets, no dependence on the orbit model exists but the scatter strongly depends on the elevation of the Sun above the orbital plane. In general, these systematic effects are significantly smaller for the FOC satellites. The z-offsets of the two analysis centers agree within the 10–15 cm level, and the time series do not show systematic effects. The application of an averaged Galileo satellite antenna model obtained from the two solutions results in a reduction of orbit day boundary discontinuities by up to one third—even if an independent software package is used. Numéro de notice : A2016-505 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0909-6 En ligne : http://dx.doi.org/10.1007/s00190-016-0909-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81529
in Journal of geodesy > vol 90 n° 8 (August 2016) . - Pages 773 - 785[article]A geometry-free and ionosphere-free multipath mitigation method for BDS three-frequency ambiguity resolution / Dezhong Chen in Journal of geodesy, vol 90 n° 8 (August 2016)
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Titre : A geometry-free and ionosphere-free multipath mitigation method for BDS three-frequency ambiguity resolution Type de document : Article/Communication Auteurs : Dezhong Chen, Auteur ; Shirong Ye, Auteur ; Jingchao Xia, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 703 – 714 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] correction du trajet multiple
[Termes IGN] erreur systématique
[Termes IGN] positionnement par BeiDou
[Termes IGN] résolution d'ambiguïté
[Termes IGN] signal BeiDou
[Termes IGN] station de référence
[Termes IGN] trajet multiple
[Termes IGN] troposphèreRésumé : (auteur) Because of the unknown systematic errors and special satellite constellations in the Beidou system (BDS), it is difficult to quickly and reliably determine the ambiguity over long-range baselines in continuously operating reference station (CORS) network. This study seeks to improve the effectiveness and reliability of BDS ambiguity resolution (AR) by combining the geometry-free and ionosphere-free (GFIF) combination and multipath mitigation algorithm. The GFIF combination composed with three-frequency signals is free of distance-dependent errors and can be used to determine the narrow lane ambiguity. The presence of multipath errors means that not all ambiguities can be correctly achieved by rounding the averaged GFIF ambiguity series. A multipath model of the single-differenced (SD) GFIF combination from the previous period is established for each individual satellite. This model is subtracted from the SD GFIF combination for the current day to remove the effects of multipath errors. Using three triangle networks with lengths of approximately 120, 80 and 50 km, we demonstrate that the proposed method improves the AR performance. The ambiguity averaged first fixing time is typically less than 1801 s for inclined geosynchronous orbit (IGSO) and medium earth orbit (MEO) satellites and less than 2007 s for the ∼42∘ elevation geostationary earth orbit (GEO) C02 satellite. However, it is more time consuming for the low-elevation GEO satellites C04 (∼18∘) and C05 (∼28∘). Kalman filtering is used to estimate the troposphere delays and two unfixed ambiguities by employing the ionosphere-free observations of all ambiguity-fixed/unfixed satellites. The experimental results show that only tens of seconds are required for AR in around 90 km baselines. Numéro de notice : A2016-503 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0903-z En ligne : http://dx.doi.org/10.1007/s00190-016-0903-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81527
in Journal of geodesy > vol 90 n° 8 (August 2016) . - pp 703 – 714[article]A multi-instrument and multi-model assessment of atmospheric moisture variability over the Western Mediterranean during HyMeX / Patrick Chazette in Quarterly Journal of the Royal Meteorological Society, vol 142 n° S1 (August 2016)
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Titre : A multi-instrument and multi-model assessment of atmospheric moisture variability over the Western Mediterranean during HyMeX Type de document : Article/Communication Auteurs : Patrick Chazette, Auteur ; Cyrille Flamant, Auteur ; Xiaoxia Shang, Auteur ; Julien Totems, Auteur ; Jean-Christophe Raut, Auteur ; Alexis Doerenbecher, Auteur ; Véronique Ducrocq, Auteur ; Nadia Fourrié, Auteur ; Olivier Bock , Auteur ; Sophie Cloché, Auteur
Année de publication : 2016 Article en page(s) : pp 7 - 22 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] données météorologiques
[Termes IGN] lidar Raman
[Termes IGN] littoral méditerranéen
[Termes IGN] modèle de simulation
[Termes IGN] modèle météorologique
[Termes IGN] positionnement par GPS
[Termes IGN] prévision météorologique
[Termes IGN] récepteur GPS
[Termes IGN] teneur en vapeur d'eauMots-clés libres : water vapour lidars Numerical Weather Prediction Models Weather Research and Forecasting model Mediterranean HyMeX cross-validation Résumé : (auteur) The Hydrological cycle in the Mediterranean eXperiment (HyMeX) was held in autumn 2012 during which part of the observational effort was established on Menorca Island to characterize the upwind marine low-level flow. The ground-based Water-vapour Raman Lidar (WALI), the airborne water-vapour lidar LEANDRE 2 and boundary-layer pressurized balloons were implemented during the first Special Observing Period and contributed to characterize water vapour variability in the vicinity of the Balearic Islands, together with the existing network of Global Positioning System receivers. Furthermore, analyses from regional and global numerical weather prediction (NWP) models (AROME-WMED, the ECMWF/IFS NWP system and the Weather Research and Forecasting (WRF) model) were also available over large domains encompassing part of or the entire western Mediterranean basin. We assess the consistency of water vapour mixing ratio (WVMR) profiles and integrated water vapour contents (IWVC) derived from the different datasets by comparing them to a common reference, the ground-based lidar WALI. We use consistency indicators such as root-mean-square errors, biases and correlations. Comparison between WVMR profiles from ground-based and airborne lidars (ground-based lidar and boundary-layer pressurized balloons) leads to a root-mean-square error lower than 1.6 g kg−1 (1.3 g kg−1) when the closest possible air masses are sampled. We observed a good agreement between the vertical WVMR profiles derived from WALI and the numerical models with correlations higher than 0.7 and root-mean-square errors lower than 2 g kg−1. Regarding IWVCs, the models exhibit biases less than 2 kg m−2, root-mean-square errors lower than 2.3 g kg−1 and correlations higher than 0.86 when compared to WALI. Finally, AROME-WMED 48 h forecasts were compared with WALI data composited over eleven 48 h periods. The quality of the forecast does not visibly degrade within the 48 h period from the initial analyses. Numéro de notice : A2016-936 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1002/qj.2671 Date de publication en ligne : 18/09/2015 En ligne : http://dx.doi.org/10.1002/qj.2671 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83164
in Quarterly Journal of the Royal Meteorological Society > vol 142 n° S1 (August 2016) . - pp 7 - 22[article]An adaptive stochastic model for GPS observations and its performance in precise point positioning / J. Z. Zheng in Survey review, vol 48 n° 349 (July 2016)
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Titre : An adaptive stochastic model for GPS observations and its performance in precise point positioning Type de document : Article/Communication Auteurs : J. Z. Zheng, Auteur ; F. Guo, Auteur Année de publication : 2016 Article en page(s) : pp 296 - 302 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] bruit (théorie du signal)
[Termes IGN] correction ionosphérique
[Termes IGN] fenêtre (informatique)
[Termes IGN] mesurage de pseudo-distance
[Termes IGN] modèle stochastique
[Termes IGN] positionnement par GPS
[Termes IGN] récepteur GPS
[Termes IGN] temps réelRésumé : (auteur) In this paper, the stochastic characteristics of Global Positioning System (GPS) pseudo-range noise as influenced by several factors such as receiver type, frequency, and ionosphere environment are analysed. The results indicate that the noise level of GPS observations is significantly affected by these factors. Moreover, the noise level is so mutable that it cannot be generalised and described by a uniform empirical model. Even for the same satellite, the noise level of observations may fluctuate sharply in both spatial and temporal resolution. To establish a reasonable stochastic model, a recursive sliding window method for estimating pseudo-range noise in real time is introduced. The effectiveness of the proposed method is verified by specific computational examples. Numéro de notice : A2016-626 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1179/1752270615Y.0000000033 En ligne : https://doi.org/10.1179/1752270615Y.0000000033 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81842
in Survey review > vol 48 n° 349 (July 2016) . - pp 296 - 302[article]Application of satellite navigation system for emergency warning and alerting / Suelynn Choy in Computers, Environment and Urban Systems, vol 58 (July 2016)
PermalinkIdentifying a low-frequency oscillation in Galileo IOV pseudorange rates / Daniele Borio in GPS solutions, vol 20 n° 3 (July 2016)
PermalinkA new method for specular and diffuse pseudorange multipath error extraction using wavelet analysis / Giovanni Pugliano in GPS solutions, vol 20 n° 3 (July 2016)
PermalinkStochastic modeling of triple-frequency BeiDou signals: estimation, assessment and impact analysis / Bofeng Li in Journal of geodesy, vol 90 n° 7 (July 2016)
PermalinkGeometric aspects of ground augmentation of satellite networks for the needs of deformation monitoring / Elżbieta Protaziuk in Artificial satellites, vol 51 n° 2 (June 2016)
PermalinkOver the borderline / Christophe Dekeyne in GEO: Geoconnexion international, vol 15 n° 6 (June 2016)
PermalinkSingle-frequency precise point positioning using multi-constellation GNSS: GPS, Glonass, Galileo and Beidou / Mahmoud Abd Rabbou in Geomatica, vol 70 n° 2 (June 2016)
PermalinkAnalysis of human mobility patterns from GPS trajectories and contextual information / Katarzyna Siła-Nowicka in International journal of geographical information science IJGIS, vol 30 n° 5-6 (May - June 2016)
Permalinkvol 30 n° 5-6 - May - June 2016 - Analysis of movement data (Bulletin de International journal of geographical information science IJGIS) / Robert Weibel
PermalinkEvaluating the use of GPS heights in water conservation applications / Ahmed F. Elaksher in Survey review, vol 48 n° 348 (May 2016)
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