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GPS satellite clock determination in case of inter-frequency clock biases for triple-frequency precise point positioning / Jiang Guo in Journal of geodesy, vol 92 n° 10 (October 2018)
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Titre : GPS satellite clock determination in case of inter-frequency clock biases for triple-frequency precise point positioning Type de document : Article/Communication Auteurs : Jiang Guo, Auteur ; Jianghui Geng, Auteur Année de publication : 2018 Article en page(s) : pp 1133 - 1142 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] erreur systématique
[Termes IGN] horloge atomique
[Termes IGN] positionnement ponctuel précis
[Termes IGN] satellite GPSRésumé : (Auteur) Significant time-varying inter-frequency clock biases (IFCBs) within GPS observations prevent the application of the legacy L1/L2 ionosphere-free clock products on L5 signals. Conventional approaches overcoming this problem are to estimate L1/L5 ionosphere-free clocks in addition to their L1/L2 counterparts or to compute IFCBs between the L1/L2 and L1/L5 clocks which are later modeled through a harmonic analysis. In contrast, we start from the undifferenced uncombined GNSS model and propose an alternative approach where a second satellite clock parameter dedicated to the L5 signals is estimated along with the legacy L1/L2 clock. In this manner, we do not need to rely on the correlated L1/L2 and L1/L5 ionosphere-free observables which complicates triple-frequency GPS stochastic models, or account for the unfavorable time-varying hardware biases in undifferenced GPS functional models since they can be absorbed by the L5 clocks. An extra advantage over the ionosphere-free model is that external ionosphere constraints can potentially be introduced to improve PPP. With 27 days of triple-frequency GPS data from globally distributed stations, we find that the RMS of the positioning differences between our GPS model and all conventional models is below 1 mm for all east, north and up components, demonstrating the effectiveness of our model in addressing triple-frequency observations and time-varying IFCBs. Moreover, we can combine the L1/L2 and L5 clocks derived from our model to calculate precisely the L1/L5 clocks which in practice only depart from their legacy counterparts by less than 0.006 ns in RMS. Our triple-frequency GPS model proves convenient and efficient in combating time-varying IFCBs and can be generalized to more than three frequency signals for satellite clock determination. Numéro de notice : A2018-460 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1106-y Date de publication en ligne : 28/12/2017 En ligne : https://doi.org/10.1007/s00190-017-1106-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91057
in Journal of geodesy > vol 92 n° 10 (October 2018) . - pp 1133 - 1142[article]Integration of ZY3-02 satellite laser altimetry data and stereo images for high-accuracy mapping / Guoyuan Li in Photogrammetric Engineering & Remote Sensing, PERS, vol 84 n° 9 (September 2018)
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Titre : Integration of ZY3-02 satellite laser altimetry data and stereo images for high-accuracy mapping Type de document : Article/Communication Auteurs : Guoyuan Li, Auteur ; Xinming Tang, Auteur ; Xiaoming Gao, Auteur ; et al., Auteur Année de publication : 2018 Article en page(s) : pp 569 - 578 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] Chine
[Termes IGN] données altimétriques
[Termes IGN] données ICEsat
[Termes IGN] image ZiYuan-3
[Termes IGN] modèle par fonctions rationnelles
[Termes IGN] ZiYuan-3Résumé : (Auteur) Integration of satellite laser altimetry data and stereo images without ground control points (GCPs) is an attractive method for global mapping. In this paper, we propose a new strategy of integrating Ziyuan3-02 (ZY3-02) satellite stereo images and laser altimetry data using a rigorous sensor model (RSM) with laser ranging constraint under the synchronized and rational function model (RFM) with laser elevation constraint under the non-synchronized capture for high-accuracy mapping without GCPs. Four experimental regions in China are selected to validate the method. The results show that the ZY3-02 satellite laser altimetry data can be used to improve the elevation accuracy of stereo images to better than 3.0 m without GCPs. All of the conclusions are valuable for the development of China's next generation of surveying and mapping satellites. Numéro de notice : A2018-362 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.14358/PERS.84.9.569 Date de publication en ligne : 01/09/2018 En ligne : https://doi.org/10.14358/PERS.84.9.569 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90673
in Photogrammetric Engineering & Remote Sensing, PERS > vol 84 n° 9 (September 2018) . - pp 569 - 578[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 105-2018091 RAB Revue Centre de documentation En réserve L003 Disponible Precise orbit determination of the Sentinel-3A altimetry satellite using ambiguity-fixed GPS carrier phase observations / Oliver Montenbruck in Journal of geodesy, vol 92 n° 7 (July 2018)
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Titre : Precise orbit determination of the Sentinel-3A altimetry satellite using ambiguity-fixed GPS carrier phase observations Type de document : Article/Communication Auteurs : Oliver Montenbruck, Auteur ; Stefan Hackel, Auteur ; Adrian Jäggi, Auteur Année de publication : 2018 Article en page(s) : pp 711 - 726 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales
[Termes IGN] données altimétriques
[Termes IGN] double différence
[Termes IGN] orbitographie
[Termes IGN] phase
[Termes IGN] Sentinel-3Résumé : (Auteur) The Sentinel-3 mission takes routine measurements of sea surface heights and depends crucially on accurate and precise knowledge of the spacecraft. Orbit determination with a targeted uncertainty of less than 2 cm in radial direction is supported through an onboard Global Positioning System (GPS) receiver, a Doppler Orbitography and Radiopositioning Integrated by Satellite instrument, and a complementary laser retroreflector for satellite laser ranging. Within this study, the potential of ambiguity fixing for GPS-only precise orbit determination (POD) of the Sentinel-3 spacecraft is assessed. A refined strategy for carrier phase generation out of low-level measurements is employed to cope with half-cycle ambiguities in the tracking of the Sentinel-3 GPS receiver that have so far inhibited ambiguity-fixed POD solutions. Rather than explicitly fixing double-difference phase ambiguities with respect to a network of terrestrial reference stations, a single-receiver ambiguity resolution concept is employed that builds on dedicated GPS orbit, clock, and wide-lane bias products provided by the CNES/CLS (Centre National d’Études Spatiales/Collecte Localisation Satellites) analysis center of the International GNSS Service. Compared to float ambiguity solutions, a notably improved precision can be inferred from laser ranging residuals. These decrease from roughly 9 mm down to 5 mm standard deviation for high-grade stations on average over low and high elevations. Furthermore, the ambiguity-fixed orbits offer a substantially improved cross-track accuracy and help to identify lateral offsets in the GPS antenna or center-of-mass (CoM) location. With respect to altimetry, the improved orbit precision also benefits the global consistency of sea surface measurements. However, modeling of the absolute height continues to rely on proper dynamical models for the spacecraft motion as well as ground calibrations for the relative position of the altimeter reference point and the CoM. Numéro de notice : A2018-453 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1090-2 Date de publication en ligne : 27/11/2017 En ligne : https://doi.org/10.1007/s00190-017-1090-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91044
in Journal of geodesy > vol 92 n° 7 (July 2018) . - pp 711 - 726[article]Estimation of antenna phase center offset for BDS IGSO and MEO satellites / Guanwen Huang in GPS solutions, vol 22 n° 2 (April 2018)
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Titre : Estimation of antenna phase center offset for BDS IGSO and MEO satellites Type de document : Article/Communication Auteurs : Guanwen Huang, Auteur ; Xingyuan Yan, Auteur ; Zhang Qian, Auteur ; et al., Auteur Année de publication : 2018 Article en page(s) : pp 22 - 49 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales
[Termes IGN] centre de phase
[Termes IGN] constellation BeiDou
[Termes IGN] orbite géostationnaire
[Termes IGN] orbitographieRésumé : (Auteur) The BeiDou satellite navigation system (BDS) is different from other global navigation satellite systems (GNSSs) because of its special constellation, which consists of satellites in geostationary earth orbit, inclined geosynchronous earth orbit (IGSO), and medium earth orbit (MEO). Compared to MEO satellites, the observations of IGSO satellites cover only a small range of nadir angles. Therefore, the estimation of phase center offsets (PCOs) suffers from high correlation with other estimation parameters. We have estimated the phase center offsets for BeiDou IGSO and MEO satellites with a direct PCO parameters model, and constraints are applied to cope with the correlation between the PCOs and other parameters. Validation shows that the estimated PCO parameters could be used to improve the accuracy of orbit and clock offset overlaps. Compared with the Multi-GNSS Experiment antenna phase center correction model, the average improvements of the proposed method for along-track, cross-track, and radial components are 19 mm (31%), 5 mm (14%), and 2 mm (15%) for MEO satellites, and 13 mm (17%), 12 mm (21%), and 5 mm (19%) for IGSO satellites. For clock offset overlaps, average improvements of standard deviation and root mean square (RMS) are 0.03 ns (20%) and 0.03 ns (12%), respectively. The RMS of precise coordinates in the BDS-only positioning was also improved significantly with a level of 24 mm (30%) in the up-direction. Finally, the overall uncertainty of the estimated results is discussed. Numéro de notice : A2018-159 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-018-0716-z Date de publication en ligne : 24/02/2018 En ligne : https://doi.org/10.1007/s10291-018-0716-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89781
in GPS solutions > vol 22 n° 2 (April 2018) . - pp 22 - 49[article]Cartographier le relief sous les forêts, et le substrat sous les déserts de sable : les attentes de la mission radar Biomass / Laurent Polidori in XYZ, n° 154 (mars - mai 2018)
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Titre : Cartographier le relief sous les forêts, et le substrat sous les déserts de sable : les attentes de la mission radar Biomass Type de document : Article/Communication Auteurs : Laurent Polidori, Auteur ; Thierry Koleck, Auteur ; Ludovic Villard, Auteur ; Mhamad El Hage, Auteur ; Philippe Paillou, Auteur ; Thuy Le Toan, Auteur Année de publication : 2018 Article en page(s) : pp 56 - 61 Note générale : Bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Missions spatiales
[Termes IGN] bande P
[Termes IGN] Biomass
[Termes IGN] désert
[Termes IGN] forêt
[Termes IGN] interféromètrie par radar à antenne synthétique
[Termes IGN] modèle numérique de terrain
[Termes IGN] polarimétrie radar
[Termes IGN] radar à antenne synthétique
[Termes IGN] tomographie radarRésumé : (Auteur) La mission spatiale Biomass sera lancée par l'Agence spatiale européenne en 2021 avec un radar à synthèse d'ouverture en bande P dans le but de cartographier la biomasse forestière à l'échelle planétaire, ainsi que la hauteur et les dégradations du couvert forestier. Plusieurs produits secondaires sont aussi envisagés, notamment la cartographie 30 du relief sous les forêts et du substrat sous les déserts de sable, qui devraient bénéficier du pouvoir de pénétration des ondes radar en bande P et de l'aptitude de la tomographie à séparer les contributions des différentes couches dans un profil vertical de rétrodiffusion. Ces possibilités ayant été démontrées lors de campagnes aéroportées, la qualité des modèles 3D attendus de la mission Biomass reste à évaluer. Numéro de notice : A2018-090 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89464
in XYZ > n° 154 (mars - mai 2018) . - pp 56 - 61[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 112-2018011 RAB Revue Centre de documentation En réserve L003 Disponible Self-shadowing of a spacecraft in the computation of surface forces : An example in planetary geodesy / Georges Balmino in Artificial satellites, vol 53 n° 1 (March 2018)
PermalinkAutomated delineation of wildfire areas using Sentinel-2 satellite imagery / Mira Weirather in GI Forum, vol 2018 n° 1 ([01/01/2018])
PermalinkCaractérisation et qualification de Modèles Numériques de Surfaces (MNS) - Analyse de la cohérence avec des masques d’eau / Guillaume Sutter (2018)
PermalinkPermalinkPermalinkTERRISCOPE, une nouvelle plateforme mutualisée de recherche en télédétection optique à partir d’avions et de drones / Yannick Boucher (2018)
PermalinkBenefits of satellite clock modeling in BDS and Galileo orbit determination / Yun Qing in Advances in space research, vol 60 n° 12 (15 December 2017)
PermalinkInSAR data for geohazard assessment in UNESCO World Heritage sites: state-of-the-art and perspectives in the Copernicus era / Deodato Tapete in International journal of applied Earth observation and geoinformation, vol 63 (December 2017)
PermalinkMICROSCOPE mission: First results of a space test of the equivalence principle / Pierre Touboul in Physical Review Letters, vol 119 n° 3 (December 2017)
PermalinkA fast cloud detection algorithm applicable to monitoring and nowcasting of daytime cloud systems / Xiao-Yong Zhuge in IEEE Transactions on geoscience and remote sensing, vol 55 n° 11 (November 2017)
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