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Interurban visibility diagnosis from point clouds / Oscar Iglesias in European journal of remote sensing, vol 49 n° 1 (2016)
[article]
Titre : Interurban visibility diagnosis from point clouds Type de document : Article/Communication Auteurs : Oscar Iglesias, Auteur ; Lucia Diaz-Vilarino, Auteur ; Higinio González-Jorge, Auteur ; Henrique Lorenzo, Auteur Année de publication : 2016 Article en page(s) : pp 673 - 690 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] analyse comparative
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] sécurité routière
[Termes IGN] semis de points
[Termes IGN] télémétrie laser aéroporté
[Termes IGN] télémétrie laser terrestre
[Termes IGN] visibilitéRésumé : (auteur) We present an approach for automatic visibility analysis in interurban roads from point clouds. The methodology is based on a ray-tracing algorithm followed by an occlusion detection to identify potential obstacles between the driver and the theoretical position of pedestrians and cyclists. As a result, the area of visibility from each driver position is obtained. The method compares the performance and suitability of point clouds acquired from both Airborne and Mobile Laser Scanning. The methodology is tested in six real case studies. In most cases, results obtained from MLS are more accurate since the point clouds are acquired from a perspective similar to driver and they have higher resolution. Numéro de notice : A2016-828 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.5721/EuJRS20164935 En ligne : http://dx.doi.org/10.5721/EuJRS20164935 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82708
in European journal of remote sensing > vol 49 n° 1 (2016) . - pp 673 - 690[article]A new method to improve the performance of multi-GNSS pseudorange positioning in signal-degraded environment / Hui Liu in Advances in space research, vol 58 n° 4 (August 2016)
[article]
Titre : A new method to improve the performance of multi-GNSS pseudorange positioning in signal-degraded environment Type de document : Article/Communication Auteurs : Hui Liu, Auteur ; Longwei Xu, Auteur ; Bao Shu, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 577 - 586 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] interopérabilité
[Termes IGN] mesurage de pseudo-distance
[Termes IGN] système de positionnement par satellites
[Termes IGN] visibilitéRésumé : (auteur) There are two existing multi-GNSS positioning methods, (1) separate receiver clock parameter is set for each constellation, (2) estimating intersystem biases (ISBs) in advance to obtain position solutions with only four unknowns. The former is the regular method and its unknowns include three receiver-coordinate parameters and several receiver clock parameters (depend on the number of participant constellations), so that it may disable when few satellites belonging to different GNSS are in view. The latter is one workable way to obtain position solution with only four visible satellites. In addition to the disabled regular method, the positioning results by the ISB-corrected method are often unsatisfactory for navigation users in signal-degraded environment. Both the deviation of ISB-solutions and the remaining measurement errors of the need corrected observations are factors to degrade location precision. Apart from these, fewer visible satellites usually cause a low robustness of the positioning model, which cause the negative influence of various errors is amplified. Based on the variation of various measurement errors, we propose a new ISSB-corrected method with observations corrected by corresponding satellite-dependent parameters. The new parameter contains the difference of time scales, hardware delays and uncorrected measurement errors between the corresponding satellite and reference, in other words, it can synthetically consider measurement errors and the ISB. By the ISSB-corrected method, we not only achieve positioning solutions with four satellites, but also significantly reduce the accuracy loss. Many experiments are conducted to present the superiority of the ISSB-corrected method. In open-area, the accuracies of regular and ISB-corrected methods are nearly equal. Apart from a similar accuracy in horizontal, the accuracy is improved by approximate 10% in up direction with respect to the two existing methods. Given the high redundancy of model in open-area, the new method may not improve the accuracy remarkably. However, it can make great contributions in signal-degraded environments. In order to compare the performance of ISB- and ISSB-corrected methods in environment with limited visible satellites, we simulate several scenarios (different satellites participant or various receivers) with only four participant satellites in the positioning solution. By the ISSB-corrected method, the 3D RMS of positioning results with four satellites is about 15 m, while it is usually worse than 25 m for the ISB-corrected method. In an urban vehicular test, the horizontal positioning error of the ISSB-corrected method is less than 20 m; and the ISB-corrected method may reach up to 70 m. Numéro de notice : A2016-592 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2016.05.016 En ligne : http://dx.doi.org/10.1016/j.asr.2016.05.016 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81748
in Advances in space research > vol 58 n° 4 (August 2016) . - pp 577 - 586[article]
Titre : Visibility estimation and joint inpainting of lidar depth maps Type de document : Article/Communication Auteurs : Marco Bevilacqua, Auteur ; Jean-François Aujol, Auteur ; Mathieu Brédif , Auteur ; Aurélie Bugeau, Auteur Editeur : New York : Institute of Electrical and Electronics Engineers IEEE Année de publication : 2016 Projets : 1-Pas de projet / Conférence : ICIP 2016, 23rd IEEE International Conference on Image Processing 25/09/2016 28/09/2016 Phoenix Arizona - Etats-Unis Proceedings IEEE Importance : pp 3503 - 3507 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] carte de profondeur
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] retouche
[Termes IGN] semis de points
[Termes IGN] visibilitéRésumé : (auteur) This paper presents a novel variational image inpainting method to solve the problem of generating, from 3-D lidar measures, a dense depth map coherent with a given color image, tackling visibility issues. When projecting the lidar point cloud onto the image plane, we generally obtain a sparse depth map, due to undersampling. Moreover, lidar and image sensor positions generally differ during acquisition, such that depth values referring to objects that are hidden from the image view point might appear with a naive projection. The proposed algorithm estimates the complete depth map, while simultaneously detecting and excluding those hidden points. It consists in a primal-dual optimization method, where a coupled total variation regularization term is included to match the depth and image gradients and a visibility indicator handles the selection of visible points. Tests with real data prove the effectiveness of the proposed strategy. Numéro de notice : C2016-035 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Autre URL associée : vers HAL Thématique : IMAGERIE Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : 10.1109/ICIP.2016.7533011 Date de publication en ligne : 19/08/2016 En ligne : https://doi.org/10.1109/ICIP.2016.7533011 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91794 Visibility and geometry of global satellite navigation systems constellations / Jacek Januszewski in Artificial satellites, vol 50 n° 4 (December 2015)
[article]
Titre : Visibility and geometry of global satellite navigation systems constellations Type de document : Article/Communication Auteurs : Jacek Januszewski, Auteur Année de publication : 2015 Article en page(s) : pp 169 - 180 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] affaiblissement géométrique de la précision
[Termes IGN] constellation BeiDou
[Termes IGN] constellation Galileo
[Termes IGN] constellation GLONASS
[Termes IGN] constellation GNSS
[Termes IGN] constellation GPS
[Termes IGN] visibilitéRésumé : (auteur) Nowadays (November 2015) there are two global fully operational satellite navigation systems, American GPS and Russian GLONASS. Two next are under construction, Galileo in Europe and BeiDou in China. As the error of observer’s position obtained from these systems depends on geometry factor DOP (Dilution Of Precision) among other things the knowledge of the number of satellites visible by this observer above given masking elevation angle Hmin and the distributions of DOP coefficient values, GDOP in particular, is very important. The lowest and the greatest number of satellites visible in open area by the observer at different latitudes for different Hmin, the percentage of satellites visible above angle H (9 intervals, each 10O wide), distributions (in per cent) of satellites azimuths (8 intervals, each 45O wide) and GDOP coefficient values (8 intervals) for Hmin = 5O for all these four systems at different observer’s latitudes (9 intervals, each wide 10O wide) are presented in the paper. Additionally the lowest elevation for which the number of satellites visible at different latitudes by the observer in open area above this angle is equal 4 or 3 and the distributions (in per cent) of GDOP coefficient values for different Hmin at observer’s latitudes 50-60O for the same four systems are showed. All calculations were made for constellation of GPS 27 satellites, GLONASS 24, Galileo 30 and BeiDou 27 MEO satellites. Numéro de notice : A2015--041 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/arsa-2015-0014 En ligne : http://dx.doi.org/10.1515/arsa-2015-0014 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81760
in Artificial satellites > vol 50 n° 4 (December 2015) . - pp 169 - 180[article]Airborne LiDAR and terrestrial laser scanning derived vegetation obstruction factors for visibility models / Jayson Murgoitio in Transactions in GIS, vol 18 n° 1 (February 2014)
[article]
Titre : Airborne LiDAR and terrestrial laser scanning derived vegetation obstruction factors for visibility models Type de document : Article/Communication Auteurs : Jayson Murgoitio, Auteur ; Rupesh Shrestha, Auteur ; Nancy Glenn, Auteur ; Lucas Spaete, Auteur Année de publication : 2014 Article en page(s) : pp 125 - 146 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] arbre (flore)
[Termes IGN] base de données dérivée
[Termes IGN] contour
[Termes IGN] corrélation
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] écosystème forestier
[Termes IGN] intégration de données
[Termes IGN] Pinus contorta
[Termes IGN] régression
[Termes IGN] télémétrie laser aéroporté
[Termes IGN] télémétrie laser terrestre
[Termes IGN] visibilitéRésumé : (Auteur) Research presented here explores the feasibility of leveraging vegetation data derived from airborne light detection and ranging (LiDAR) and terrestrial laser scanning (TLS) for visibility modeling. Using LiDAR and TLS datasets of a lodgepole pine (Pinus contorta) dominant ecosystem, tree canopy and trunk obstructions were isolated relevant to a discrete visibility beam in a short-range line-of-sight model. Cumulative obstruction factors from vegetation were compared with reference visibility values from digital photographs along sightline paths. LiDAR-derived tree factors were augmented with single-scan TLS data for obstruction prediction. Good correlation between datasets was found up to 10 m from the terrestrial scanner, but fine scale visibility modeling was problematic at longer distances. Analysis of correlation and regression results reveal the influence of obstruction shadowing inherent to discrete LiDAR and TLS, potentially limiting the feasibility of modeling visibility over large areas with similar technology. However, the results support the potential for TLS-derived subcanopy metrics for augmenting large amounts of aerial LiDAR data to significantly improve models of forest structure. Subtle LiDAR processing improvements, including more accurate tree delineation through higher point density aerial data, combined with better vegetation quantification processes for TLS data, will advance the feasibility and accuracy of data integration. Numéro de notice : A2014-069 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/tgis.12022 Date de publication en ligne : 17/05/2013 En ligne : https://doi.org/10.1111/tgis.12022 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32974
in Transactions in GIS > vol 18 n° 1 (February 2014) . - pp 125 - 146[article]Programmation Python pour Arcgis (6) : un exemple d'amélioration de l'outil "champs de vision" (viewshed) / Eric Bailly in Géomatique expert, n° 95 (01/11/2013)PermalinkThe influence of digital surface model choice on visibility-based mobile geospatial applications / Sam Meek in Transactions in GIS, vol 17 n° 4 (August 2013)PermalinkAutomatic generation of 2.5D terrain models without occluding routes of interest / Hao Deng in Photogrammetric Engineering & Remote Sensing, PERS, vol 78 n° 11 (November 2012)PermalinkMultidirectional visibility index for analytical shading enhancement / T. Podobnikar in Cartographic journal (the), vol 49 n° 3 (August 2012)PermalinkExploration of information: theoretic arguments for the limited amount of information in a map / J. Bjorke in Cartography and Geographic Information Science, vol 39 n° 2 (April 2012)PermalinkCartographier la visibilité de la mer pour la gestion d'un littoral : une expérimentation sur la Côte d'Azur / Samuel Robert in Espace géographique, vol 40 n° 3 (juillet - septembre 2011)PermalinkEstimating meteorological visibility using cameras: A probabilistic model-driven approach / Nicolas Hautière (2011)PermalinkThree dimensional query / J. Carswell in GIM international, vol 24 n° 8 (August 2010)PermalinkLe geomarketing, outil d'aide à la prise de décision dans la communication événementielle / A. Baili (2009)PermalinkSpatial Information Theory, COSIT 2009, 9th International Conference, Aber Wrac'h, France, September 2009 / Kathleen Stewart Hornsby (2009)Permalink