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Assessing a new velocity field in Greece towards a new semi-kinematic datum / S. Bitharis in Survey review, vol 51 n° 368 (September 2019)  

Public [article]  inSurvey review > vol 51 n° 368 (September 2019) . - pp 450 - 459 Titre : Assessing a new velocity field in Greece towards a new semi-kinematic datum Type de document : Article/Communication Auteurs : S. Bitharis, Auteur ; N. Papadopoulos, Auteur ; C. Pikridas, Auteur ; et al., Auteur Année de publication : 2019 Article en page(s) : pp 450 - 459 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes descripteurs IGN] champ de vitesse [Termes descripteurs IGN] déformation de la croute terrestre [Termes descripteurs IGN] géodynamique [Termes descripteurs IGN] Grèce [Termes descripteurs IGN] réseau géodésique local [Termes descripteurs IGN] système de référence local Résumé : (Auteur) Greece has always been an interesting study area for the geodesists due to its intense geodynamic behaviour. Especially, the exploitation of a modern geodetic velocity field using GNSS becomes a crucial requirement for geodetic purposes. The main aim of the present study is the assessment of a modern geodetic velocity model. This procedure is based on the unification of various reference frames, implemented from individual extended GNSS campaigns in different epochs with the effective involvement of the Hellenic Military Geographic Service. The implementation of geodetic velocities in the inhomogeneous Greek velocity field improves significantly the reliability of transformations, more than 60% with respect to the horizontal component, applying a vice versa time shift to a common epoch. We also emphasise the necessity to adopt a velocity model in order to process regional GNSS networks and therefore to establish a modern semi-kinematic reference frame in Greece. Numéro de notice : A2019-386 Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2018.1479937 date de publication en ligne : 02/06/2018 En ligne : https://doi.org/10.1080/00396265.2018.1479937 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93476 [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)    

Public [article]  inRemote sensing > vol 10 n° 6 (June 2018) 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 ; N. 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 descripteurs IGN] analyse en composantes principales [Termes descripteurs IGN] champ de vitesse [Termes descripteurs IGN] Chine [Termes descripteurs IGN] coordonnées GPS [Termes descripteurs IGN] correction géométrique [Termes descripteurs IGN] données GPS [Termes descripteurs IGN] réseau de surveillance géophysique [Termes descripteurs IGN] série temporelle [Termes descripteurs IGN] station permanente Résumé : (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 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 [article]

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Appraisal of the Hellenic Geodetic Reference System 1987 based on backward-transformed ITRF coordinates using a national velocity model / M. Chatzinikos in Survey review, vol 49 n° 356 (November 2017)  

Public [article]  inSurvey review > vol 49 n° 356 (November 2017) . - pp 386 - 398 Titre : Appraisal of the Hellenic Geodetic Reference System 1987 based on backward-transformed ITRF coordinates using a national velocity model Type de document : Article/Communication Auteurs : M. Chatzinikos, Auteur ; C. Kotsakis, Auteur Année de publication : 2017 Article en page(s) : pp 386 - 398 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux [Termes descripteurs IGN] champ de vitesse [Termes descripteurs IGN] géodynamique [Termes descripteurs IGN] Grèce [Termes descripteurs IGN] International Terrestrial Reference Frame [Termes descripteurs IGN] transformation de coordonnées Résumé : (Auteur) The paper presents a detailed accuracy evaluation of the Hellenic Geodetic Reference System 1987 (HGRS87), a non-geocentric traditional local datum which was established thirty years ago and it is still used as the official coordinate system for surveying applications in Greece. This is the first time that a large-scale assessment of HGRS87 is performed, which aims to reveal its weakness by quantifying its consistency with a higher quality ITRF/GNSS-based frame over the entire country. A geodetic velocity model is employed in our analysis in an attempt to eliminate the accumulated geodynamical distortions of the (static) HGRS87 coordinates, and thus to provide a more judicious comparison between the underlying frames at a common epoch. Our results show that, even after removing the geodynamical distortions, the average accuracy of HGRS87 at national scale remains worse than 45 cm, yet significant variations exist in its regional accuracy level over different parts of Greece. Numéro de notice : A2017-557 Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/00396265.2016.1180797 En ligne : https://doi.org/10.1080/00396265.2016.1180797 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86618 [article]

GPS coordinate time series measurements in Ontario and Quebec, Canada / Hadis Samadi Alinia in Journal of geodesy, vol 91 n° 6 (June 2017)  

Public [article]  inJournal of geodesy > vol 91 n° 6 (June 2017) . - pp 653 - 683 Titre : GPS coordinate time series measurements in Ontario and Quebec, Canada Type de document : Article/Communication Auteurs : Hadis Samadi Alinia, Auteur ; Christy F. Tiampo, Auteur ; Thomas S. James, Auteur Année de publication : 2017 Article en page(s) : pp 653 - 683 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux [Termes descripteurs IGN] Bernese [Termes descripteurs IGN] bruit (théorie du signal) [Termes descripteurs IGN] bruit blanc [Termes descripteurs IGN] champ de vitesse [Termes descripteurs IGN] coordonnées GPS [Termes descripteurs IGN] épaisseur de la glace [Termes descripteurs IGN] Hudson, baie d' [Termes descripteurs IGN] méthode du maximum de vraisemblance (estimation) [Termes descripteurs IGN] Ontario [Termes descripteurs IGN] Québec (Canada) [Termes descripteurs IGN] série temporelle [Termes descripteurs IGN] station permanente Résumé : (Auteur) New precise network solutions for continuous GPS (cGPS) stations distributed in eastern Ontario and western Québec provide constraints on the regional three-dimensional crustal velocity field. Five years of continuous observations at fourteen cGPS sites were analyzed using Bernese GPS processing software. Several different sub-networks were chosen from these stations, and the data were processed and compared to in order to select the optimal configuration to accurately estimate the vertical and horizontal station velocities and minimize the associated errors. The coordinate time series were then compared to the crustal motions from global solutions and the optimized solution is presented here. A noise analysis model with power-law and white noise, which best describes the noise characteristics of all three components, was employed for the GPS time series analysis. The linear trend, associated uncertainties, and the spectral index of the power-law noise were calculated using a maximum likelihood estimation approach. The residual horizontal velocities, after removal of rigid plate motion, have a magnitude consistent with expected glacial isostatic adjustment (GIA). The vertical velocities increase from subsidence of almost 1.9 mm/year south of the Great Lakes to uplift near Hudson Bay, where the highest rate is approximately 10.9 mm/year. The residual horizontal velocities range from approximately 0.5 mm/year, oriented south–southeastward, at the Great Lakes to nearly 1.5 mm/year directed toward the interior of Hudson Bay at stations adjacent to its shoreline. Here, the velocity uncertainties are estimated at less than 0.6 mm/year for the horizontal component and 1.1 mm/year for the vertical component. A comparison between the observed velocities and GIA model predictions, for a limited range of Earth models, shows a better fit to the observations for the Earth model with the smallest upper mantle viscosity and the largest lower mantle viscosity. However, the pattern of horizontal deformation is not well explained in the north, along Hudson Bay, suggesting that revisions to the ice thickness history are needed to improve the fit to observations. Numéro de notice : A2017-287 Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern En ligne : http://doi.org/10.1007/s00190-016-0987-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85320 [article]

Active interseismic shallow deformation of the Pingting terraces (Longitudinal Valley – Eastern Taiwan) from UAV high-resolution topographic data combined with InSAR time series / Benoit Deffontaines in Geomatics, Natural Hazards and Risk, vol 8 (2017)  

Public [article]  inGeomatics, Natural Hazards and Risk > vol 8 (2017) . - pp 120 - 136 Titre : Active interseismic shallow deformation of the Pingting terraces (Longitudinal Valley – Eastern Taiwan) from UAV high-resolution topographic data combined with InSAR time series Type de document : Article/Communication Auteurs : Benoit Deffontaines , Auteur ; Kuo-Jen Chang, Auteur ; Johann Champenois, Auteur ; Bénédicte Fruneau , Auteur ; Erwan Pathier, Auteur ; Jyr-Ching Hu, Auteur ; Shih-Ting Lu, Auteur ; Yen-Chiu Liu, Auteur Année de publication : 2017 Projets : 1-Pas de projet / Article en page(s) : pp 120 - 136 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes descripteurs IGN] bande L [Termes descripteurs IGN] champ de vitesse [Termes descripteurs IGN] déformation de la croute terrestre [Termes descripteurs IGN] drone [Termes descripteurs IGN] faille géologique [Termes descripteurs IGN] image aérienne [Termes descripteurs IGN] image ALOS-PALSAR [Termes descripteurs IGN] image radar moirée [Termes descripteurs IGN] modèle numérique de terrain [Termes descripteurs IGN] Taïwan Résumé : (auteur) We focus herein on the location, characterization and the quantification of the most active structural feature of Taiwan: the Longitudinal Valley Fault that corresponds to the suture in between the Philippine and Eurasian Plates. In order to determine and monitor its present inter-seismic deformation, we focus on the Pingting Terraces area, situated in the South Longitudinal Valley (Eastern Taiwan). We first determine the structural geometry issued from both photo-interpretation deduced from new unmanned aerial vehicle (UAV) high-resolution Digital Terrain Model data that we acquired (34.78 km2 with 7.73 cm ground sampling distance), combined with geological field work. In order to characterize and quantify the present deformational patterns over the Pingting terraces, we used an InSAR time series Interferometry algorithm (MT-InSAR) applied to nine L-band SAR images from ALOS satellite acquired over the period 2007–2010. The unprecedented density of measurements (about 120 points per km2 for a total of 6,400 points) gives a continuous overview of the inter-seismic shallow deformation. The structural geometry combined with the mean velocity map (MT-InSAR) reveals two clear active faults situated above the scarps of the Pingting terraces and responsible for up to 7 and 20 mm/yr velocity offset along the radar line of sight. A temporal analysis of the deformation is performed with one measurement at each SAR acquisition date, giving major improvements in the characterization and quantification of the Longitudinal Valley active Fault trace. Numéro de notice : A2017-840 Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/19475705.2016.1181678 date de publication en ligne : 25/07/2016 En ligne : https://doi.org/10.1080/19475705.2016.1181678 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89350 [article]

Monitoring rock glaciers by combining photogrammetric and GNSS-based methods / Fabian Neyer (2017)  

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Champ de vitesse GPS du Nord-Est de la France : apport des stations permanentes pour une précision submillimétrique / Eric Henrion in XYZ, n° 142 (mars - mai 2015)

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Analyse temps-frequence et traitement des signaux RSO à haute résolution spatiale pour la surveillance des grands ouvrages d'art / Andrei Anghel (2015)  

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Implementation of the ETRS89 in Europe: Current Status and Challenges / Carine Bruyninx (2015)  

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A continuous velocity field for Norway / Halfdan Pascal Kierulf in Journal of geodesy, vol 87 n° 4 (April 2013)  

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Photogrammetric techniques for the determination of spatio-temporal velocity fields at glaciar San Rafael, Chile / H. Maas in Photogrammetric Engineering & Remote Sensing, PERS, vol 79 n° 3 (March 2013)  

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Mitigating the effects of vertical land motion in tide gauge records using a state-of-the-art GPS velocity field / Alvaro Santamaria Gomez in Global and Planetary Change, vol 98 - 99 (December 2012)  

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Photogrammetric techniques for voxel-based flow velocity field measurement / P. Westfeld in Photogrammetric record, vol 26 n° 136 (December 2011 - February 2012)  

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vol 26 n° 136 - December 2011 - February 2012 - Special issue: ISPRS commission V [5] Symposium 2010 close range image measurement techniques (Bulletin de Photogrammetric record) / Remote sensing and photogrammetry society  

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Analysis of long-term GPS observations in Greece (1993-2009) and geodynamic implications for the Eastern Mediterranean / Michael D. Müller (2011)    

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