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Performance evaluation of GNSS-TEC estimation techniques at the grid point in middle and low latitudes during different geomagnetic conditions / O. E. Abe in Journal of geodesy, vol 91 n° 4 (April 2017)
[article]
Titre : Performance evaluation of GNSS-TEC estimation techniques at the grid point in middle and low latitudes during different geomagnetic conditions Type de document : Article/Communication Auteurs : O. E. Abe, Auteur ; X. Otero Villamide, Auteur ; C. Paparini, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 409 - 417 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] champ géomagnétique
[Termes IGN] erreur systématique
[Termes IGN] Espagne
[Termes IGN] estimation statistique
[Termes IGN] étalonnage
[Termes IGN] évaluation
[Termes IGN] Ghana
[Termes IGN] latitude
[Termes IGN] performance
[Termes IGN] signal GNSS
[Termes IGN] teneur totale en électrons
[Termes IGN] traitement du signalRésumé : (auteur) Global Navigation Satellite Systems (GNSS) have become a powerful tool use in surveying and mapping, air and maritime navigation, ionospheric/space weather research and other applications. However, in some cases, its maximum efficiency could not be attained due to some uncorrelated errors associated with the system measurements, which is caused mainly by the dispersive nature of the ionosphere. Ionosphere has been represented using the total number of electrons along the signal path at a particular height known as Total Electron Content (TEC). However, there are many methods to estimate TEC but the outputs are not uniform, which could be due to the peculiarity in characterizing the biases inside the observables (measurements), and sometimes could be associated to the influence of mapping function. The errors in TEC estimation could lead to wrong conclusion and this could be more critical in case of safety-of-life application. This work investigated the performance of Ciraolo’s and Gopi’s GNSS-TEC calibration techniques, during 5 geomagnetic quiet and disturbed conditions in the month of October 2013, at the grid points located in low and middle latitudes. The data used are obtained from the GNSS ground-based receivers located at Borriana in Spain (40∘N, 0∘E; mid latitude) and Accra in Ghana (5.50∘N, −0.20∘E; low latitude). The results of the calibrated TEC are compared with the TEC obtained from European Geostationary Navigation Overlay System Processing Set (EGNOS PS) TEC algorithm, which is considered as a reference data. The TEC derived from Global Ionospheric Maps (GIM) through International GNSS service (IGS) was also examined at the same grid points. The results obtained in this work showed that Ciraolo’s calibration technique (a calibration technique based on carrier-phase measurements only) estimates TEC better at middle latitude in comparison to Gopi’s technique (a calibration technique based on code and carrier-phase measurements). At the same time, Gopi’s calibration was also found more reliable in low latitude than Ciraolo’s technique. In addition, the TEC derived from IGS GIM seems to be much reliable in middle-latitude than in low-latitude region. Numéro de notice : A2017-107 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0972-z En ligne : http://dx.doi.org/10.1007/s00190-016-0972-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84497
in Journal of geodesy > vol 91 n° 4 (April 2017) . - pp 409 - 417[article]Monitoring of vertical deformations by means high-precision geodetic levelling. Test case : The Arenoso dam (South of Spain) / M. Clara de Lacy in Journal of applied geodesy, vol 11 n° 1 (March 2017)
[article]
Titre : Monitoring of vertical deformations by means high-precision geodetic levelling. Test case : The Arenoso dam (South of Spain) Type de document : Article/Communication Auteurs : M. Clara de Lacy, Auteur ; M. Isabel Ramos, Auteur Année de publication : 2017 Article en page(s) : pp 31 - 42 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] barrage
[Termes IGN] déformation verticale de la croute terrestre
[Termes IGN] Espagne
[Termes IGN] génie civil
[Termes IGN] nivellement direct
[Termes IGN] réseau géodésique spécifique
[Termes IGN] surveillance d'ouvrage
[Termes IGN] topométrie de précisionRésumé : (Auteur) The Arenoso reservoir is created by an embankment dam, with central clay core, slates and greywacke shoulders. This kind of engineering structure is subject of deformation due to factors such as changes of water level of the reservoir, seat structure, climate changes, etc. In general, dam monitoring involves measurements both outside (external shell) and inside the structure. A number of control points is established around the area of the dam and the measurements of the displacements of the control points take place at several epochs. In this study high-precision levelling techniques have been used to monitor the vertical deformations. In particular five high-precision levelling profiles were measured in five surveys: February and July 2008, March and July 2013 and August 2014. In this study the design, observations and results are presented. On the one hand the results put in evidence the precision of the observations that are always under 1-mm level. On the other hand these results indicate downstream (southeastward) motion of the thrust block center of the dam probably during the fall and winter. The subsidence reachs here the maximum with a value of −14 cm in 2014 (in respect of February 2008). The displacements observed at the berms of the dam exhibit a similar trend to the displacements observed at the crest but they are significantly smaller, as expected. The accumulative vertical displacements and the settlement index indicate the magnitude of the movements decrease in time, confirming the dam tends to stabilize. Numéro de notice : A2017-282 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2016-0034 En ligne : https://doi.org/10.1515/jag-2016-0034 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85315
in Journal of applied geodesy > vol 11 n° 1 (March 2017) . - pp 31 - 42[article]Wetland monitoring with Global Navigation Satellite System reflectometry / Son V. Nghiem in Earth and space science, vol 4 n° 1 (January 2017)
[article]
Titre : Wetland monitoring with Global Navigation Satellite System reflectometry Type de document : Article/Communication Auteurs : Son V. Nghiem, Auteur ; Cinzia Zuffada, Auteur ; Rashmi Shah, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 16 - 39 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] delta
[Termes IGN] Ebre (bassin)
[Termes IGN] Espagne
[Termes IGN] méthane
[Termes IGN] réflectométrie par GNSS
[Termes IGN] zone humideRésumé : (auteur) Information about wetland dynamics remains a major missing gap in characterizing, understanding, and projecting changes in atmospheric methane and terrestrial water storage. A review of current satellite methods to delineate and monitor wetland change shows some recent advances, but much improved sensing technologies are still needed for wetland mapping, not only to provide more accurate global inventories but also to examine changes spanning multiple decades. Global Navigation Satellite Systems Reflectometry (GNSS-R) signatures from aircraft over the Ebro River Delta in Spain and satellite measurements over the Mississippi River and adjacent watersheds demonstrate that inundated wetlands can be identified under different vegetation conditions including a dense rice canopy and a thick forest with tall trees, where optical sensors and monostatic radars provide limited capabilities. Advantages as well as constraints of GNSS-R are presented, and the synergy with various satellite observations are considered to achieve a breakthrough capability for multidecadal wetland dynamics monitoring with frequent global coverage at multiple spatial and temporal scales. Numéro de notice : A2017-278 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1002/2016EA000194 En ligne : https://doi.org/10.1002/2016EA000194 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85302
in Earth and space science > vol 4 n° 1 (January 2017) . - pp 16 - 39[article]Self-thinning in four pine species : an evaluation of potential climate impacts / Pau Brunet-Navarro in Annals of Forest Science, vol 73 n° 4 (December 2016)
[article]
Titre : Self-thinning in four pine species : an evaluation of potential climate impacts Type de document : Article/Communication Auteurs : Pau Brunet-Navarro, Auteur ; Frank J. Sterck, Auteur ; Jordi Vayreda, Auteur ; Jordi Martinez-Vilalta, Auteur ; Godefridus M.J. Mohren, Auteur Année de publication : 2016 Article en page(s) : pp 1025 - 1034 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] auto-éclaircie
[Termes IGN] Catalogne (Espagne)
[Termes IGN] changement climatique
[Termes IGN] diamètre des arbres
[Termes IGN] Pinus halepensis
[Termes IGN] Pinus mugo subsp. uncinata
[Termes IGN] Pinus nigra
[Termes IGN] Pinus sylvestris
[Termes IGN] variabilité
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (Auteur) Self-thinning lines are species- and climate-specific, and they should be used when assessing the capacity of different forest stands to increase biomass/carbon storage.
Context : The capacity of forests to store carbon can help to mitigate the effects of atmospheric CO2 rise and climate change. The self-thinning relationship (average size measure ∼ stand density) has been used to identify the potential capacity of biomass storage at a given density and to evaluate the effect of stand management on stored carbon. Here, a study that shows how the self-thinning line varies with species and climate is presented.
Aims : Our main objective is thus testing whether species identity and climate affect the self-thinning line and therefore the potential amount of carbon stored in living biomass.
Methods : The Ecological and Forest Inventory of Catalonia was used to calculate the self-thinning lines of four common coniferous species in Catalonia, NE Iberian Peninsula (Pinus halepensis, Pinus nigra, Pinus sylvestris and Pinus uncinata). Quadratic mean diameter at breast height was chosen as the average size measure. The self-thinning lines were used to predict the potential diameter at a given density and study the effect of environmental variability.
Results : Species-specific self-thinning lines were obtained. The self-thinning exponent was consistent with the predicted values of −3/2 and −4/3 for mass-based scaling for all species except P. sylvestris. Species identity and climatic variability within species affected self-thinning line parameters.
Conclusion : Self-thinning lines are species-specific and are affected by climatic conditions. These relationships can be used to refine predictions of the capacity of different forest stands to increase biomass/carbon storage.Numéro de notice : A2016--013 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article DOI : 10.1007/s13595-016-0585-y En ligne : http://dx.doi.org/10.1007/s13595-016-0585-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83859
in Annals of Forest Science > vol 73 n° 4 (December 2016) . - pp 1025 - 1034[article]A simulated annealing algorithm for zoning in planning using parallel computing / Inès Santé in Computers, Environment and Urban Systems, vol 59 (September 2016)
[article]
Titre : A simulated annealing algorithm for zoning in planning using parallel computing Type de document : Article/Communication Auteurs : Inès Santé, Auteur ; Francisco F. Rivera, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 95 - 106 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] algorithme du recuit simulé
[Termes IGN] Galice (Espagne)
[Termes IGN] optimisation (mathématiques)
[Termes IGN] parcelle cadastrale
[Termes IGN] partition d'image
[Termes IGN] polygone
[Termes IGN] processeur multicoeur
[Termes IGN] utilisation du solRésumé : (auteur) There is an increasing demand for tools that support land use planning processes, particularly the design of zoning maps, which is one of the most complex tasks in the field. In this task, different land use categories need to be allocated according to multiple criteria. The problem can be formalized in terms of a multiobjective problem. This paper generalizes and complements a previous work on this topic. It presents an algorithm based on a simulated annealing heuristic that optimizes the delimitation of land use categories on a cadastral parcel map according to suitability and compactness criteria. The relative importance of both criteria can be adapted to any particular case. Despite its high computational cost, the use of plot polygons was decided because it is realistic in terms of technical application and land use laws. Due to the computational costs of our proposal, parallel implementations are required, and several approaches for shared memory systems such as multicores are analysed in this paper. Results on a real case study conducted in the Spanish municipality of Guitiriz show that the parallel algorithm based on simulated annealing is a feasible method to design alternative zoning maps. Comparisons with results from experts are reported, and they show a high similarity. Results from our strategy outperform those by experts in terms of suitability and compactness. The parallel version of the code produces good results in terms of speed-up, which is crucial for taking advantage of the architecture of current multicore processors. Numéro de notice : A2016-407 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.compenvurbsys.2016.05.005 Date de publication en ligne : 10/06/2016 En ligne : http://dx.doi.org/10.1016/j.compenvurbsys.2016.05.005 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81240
in Computers, Environment and Urban Systems > vol 59 (September 2016) . - pp 95 - 106[article]Use of the gyrotheodolite in underground networks of long high-speed railway tunnels / J. Velasco-Gómez, in Survey review, vol 48 n° 350 (September 2016)PermalinkThe 3d model-map of Cadiz (1779): A unique project of cartography in modern Spain / Gabriel Granado-Castro in Cartographic journal (the), Vol 53 n° 3 (August 2016)PermalinkDeveloping a dynamic growth model for maritime pine in Asturias (NW Spain): comparison with nearby regions / Manuel Arias-Rodil in Annals of Forest Science, vol 73 n° 2 (June 2016)PermalinkUne frontière pour les Pyrénées : l'épisode trop méconnu de la commission topographique franco-espagnole Caro-Ornano / Jean-Yves Puyo in Cartes & Géomatique, n° 228 (juin - août 2016)PermalinkLes temps de transport pour délimiter des aires urbaines fonctionnelles ? Une investigation critique à partir de trois métropoles européennes / Marianne Guérois in Belgeo, vol 2016 n° 2 (2016-2)PermalinkDistribution patterns of forest species along an Atlantic-Mediterranean environmental gradient: an approach from forest inventory data / A. Olthoff in Forestry, an international journal of forest research, vol 89 n° 1 (January 2016)PermalinkSpatial analysis of heath toponymy in relation to present-day heathland distribution / Jaime Fagundez in International journal of geographical information science IJGIS, vol 30 n° 1-2 (January - February 2016)PermalinkWater vapor measurements by mobile Raman lidar over the Mediterranean Sea in the framework of HyMeX: application to multi-platform validation of moisture profiles / Julien Totems in EPJ Web of Conferences, vol 119 (2016)PermalinkThe pine shoot beetle Tomicus piniperda as a plausible vector of Fusarium circinatum in northern Spain / Diana Bezos in Annals of Forest Science, vol 72 n° 8 (December 2015)PermalinkTree rings reflect growth adjustments and enhanced synchrony among sites in Iberian stone pine (Pinus pinea L.) under climate change / Fabio Natalini in Annals of Forest Science, vol 72 n° 8 (December 2015)Permalink