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Auteur Frédéric Bretar
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PhD student at MATIS (2003-2006) - researcher at MATIS => 2008/2009 then researcher at CETE Normandie devenu CEREMA
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Canopy density model: A new ALS-derived product to generate multilayer crown cover maps / António Ferraz in IEEE Transactions on geoscience and remote sensing, vol 53 n° 12 (December 2015)
[article]
Titre : Canopy density model: A new ALS-derived product to generate multilayer crown cover maps Type de document : Article/Communication Auteurs : António Ferraz , Auteur ; Clément Mallet , Auteur ; Stéphane Jacquemoud, Auteur ; Gil Rito-Gonçalves , Auteur ; Margarida Tomé, Auteur ; Paola Soares, Auteur ; Luisa M. Gomes Pereira, Auteur ; Frédéric Bretar, Auteur Année de publication : 2015 Article en page(s) : pp 6776 - 6790 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] canopée
[Termes IGN] carte de la végétation
[Termes IGN] données de terrain
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] estimation par noyau
[Termes IGN] Portugal
[Termes IGN] sous-étage
[Termes IGN] structure d'un peuplement forestier
[Termes IGN] traitement d'imageRésumé : (auteur) The canopy density model (CDM), a new product interpolated from airborne laser scanner (ALS) data and dedicated to forest structure characterization is presented. It exploits both the multiecho capability of the ALS and a nonparametric density estimation technique called kernel density estimators (KDEs). The CDM is used to delineate the outmost perimeter of vegetation features and to compute forest crown cover (CrCO). Contrary to other works that focus on single-layer forest canopies, CrCo is derived here for each layer, namely, the overstory, the understory, and ground vegetation. The root-mean-square error of prediction determined by using field data acquired over 44 forest stands in a forest in Portugal allows the testing of the reliability of the method: It ranges from 6.21% (overstory) to 13.76% (ground vegetation). In addition, we investigate the ability of the CDM to map the CrCo for individual trees. Finally, two existing methods have been applied to our study site in order to assess improvements, advantages, and drawbacks of our approach. Numéro de notice : A2015-840 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2015.2448056 Date de publication en ligne : 10/08/2015 En ligne : http://dx.doi.org/10.1109/TGRS.2015.2448056 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79180
in IEEE Transactions on geoscience and remote sensing > vol 53 n° 12 (December 2015) . - pp 6776 - 6790[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 065-2015121 SL Revue Centre de documentation Revues en salle Disponible Quantification of L-band InSAR coherence over volcanic areas using LiDAR and in situ measurements / Mélanie Arab-Sedze in Remote sensing of environment, vol 152 (September 2014)
[article]
Titre : Quantification of L-band InSAR coherence over volcanic areas using LiDAR and in situ measurements Type de document : Article/Communication Auteurs : Mélanie Arab-Sedze, Auteur ; Essam Heggy, Auteur ; Frédéric Bretar, Auteur ; Daniel Berveiller, Auteur ; Stéphane Jacquemoud, Auteur Année de publication : 2014 Article en page(s) : pp 202 - 216 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image mixte
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] image ALOS-PALSAR
[Termes IGN] image SPOT 5
[Termes IGN] interféromètrie par radar à antenne synthétique
[Termes IGN] Leaf Area Index
[Termes IGN] Piton de la Fournaise (volcan)
[Termes IGN] propriété diélectrique
[Termes IGN] Réunion, île de la
[Termes IGN] volcanRésumé : (auteur) Interferometric Synthetic Aperture Radar (InSAR) is a powerful tool to monitor large-scale ground deformation at active volcanoes. However, vegetation and pyroclastic deposits degrade the radar coherence and therefore the measurement of 3-D surface displacements. In this article, we explore the complementarity between ALOS–PALSAR coherence images, airborne LiDAR data and in situ measurements acquired over the Piton de La Fournaise volcano (Reunion Island, France) to determine the sources of errors that may affect repeat-pass InSAR measurements. We investigate three types of surfaces: terrains covered with vegetation, lava flows (a′a, pahoehoe or slabby pahoehoe lava flows) and pyroclastic deposits (lapilli). To explain the loss of coherence observed over the Dolomieu crater between 2008 and 2009, we first use laser altimetry data to map topographic variations. The LiDAR intensity, which depends on surface reflectance, also provides ancillary information about the potential sources of coherence loss. In addition, surface roughness and rock dielectric properties of each terrain have been determined in situ to better understand how electromagnetic waves interact with such media: rough and porous surfaces, such as the a′a lava flows, produce a higher coherence loss than smoother surfaces, such as the pahoehoe lava flows. Variations in dielectric properties suggest a higher penetration depth in pyroclasts than in lava flows at L-band frequency. Decorrelation over the lapilli is hence mainly caused by volumetric effects. Finally, a map of LAI (Leaf Area Index) produced using SPOT 5 imagery allows us to quantify the effect of vegetation density: radar coherence is negatively correlated with LAI and is unreliable for values higher than 7.5. Numéro de notice : A2014-812 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2014.06.011 Date de publication en ligne : 11/07/2014 En ligne : https://doi.org/10.1016/j.rse.2014.06.011 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89039
in Remote sensing of environment > vol 152 (September 2014) . - pp 202 - 216[article]Assessment of an ancient bridge combining geophysical and advanced photogrammetric methods: Application to the Pont De Coq / Cyrille Fauchard in Journal of applied geophysics, vol 98 (November 2013)
[article]
Titre : Assessment of an ancient bridge combining geophysical and advanced photogrammetric methods: Application to the Pont De Coq Type de document : Article/Communication Auteurs : Cyrille Fauchard, Auteur ; Raphaël Antoine, Auteur ; Frédéric Bretar, Auteur ; Julien Lacogne, Auteur ; Yannick Fargier, Auteur ; Cindy Maisonnave, Auteur ; Vincent Guilbert, Auteur ; Pierre Marjerie, Auteur ; Paul-Franck Thérain, Auteur ; Jean-Paul Dupont, Auteur ; Marc Pierrot-Deseilligny , Auteur Année de publication : 2013 Projets : 1-Pas de projet / Article en page(s) : pp 100 -112 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] APERO
[Termes IGN] auscultation d'ouvrage
[Termes IGN] MicMac
[Termes IGN] modèle 3D du site
[Termes IGN] ouvrage d'art
[Termes IGN] patrimoine immobilier
[Termes IGN] photogrammétrie numérique
[Termes IGN] pont
[Termes IGN] radar pénétrant GPR
[Termes IGN] surveillance d'ouvrage
[Termes IGN] tomographieRésumé : (auteur) A high resolution geophysical survey was carried out on the Pont De Coq, a medieval stone arch bridge located in Normandy (France) in 2011 and 2012. Two complementary methods are used: Electrical Resistivity Tomography (ERT) and Ground Penetrating Radar (GPR). They allow to evaluate the structural state of the bridge and to characterize the subsurface around and beneath the bridge. An excellent correlation is obtained between the geophysical methods and the geological data obtained around the bridge. In order to improve the restitution of the geophysical data, an advanced photogrammetric method is performed, providing a high resolution 3D Digital Terrain Model (DTM) of the Pont de Coq. The advanced photogrammetry enhances the presentation of the GPR and ERT data. This approach is an easy-to-use, rapid and cost-effective tool for stakeholders. Finally, it is a promising and original method for improved interpretations of future geophysical surveys. Numéro de notice : A2013-810 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Thématique : IMAGERIE Nature : Article DOI : 10.1016/j.jappgeo.2013.08.009 Date de publication en ligne : 26/08/2013 En ligne : https://doi.org/10.1016/j.jappgeo.2013.08.009 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80094
in Journal of applied geophysics > vol 98 (November 2013) . - pp 100 -112[article]An advanced photogrammetric method to measure surface roughness: Application to volcanic terrains in the Piton de la Fournaise, Reunion Island / Frédéric Bretar in Remote sensing of environment, vol 135 (August 2013)
[article]
Titre : An advanced photogrammetric method to measure surface roughness: Application to volcanic terrains in the Piton de la Fournaise, Reunion Island Type de document : Article/Communication Auteurs : Frédéric Bretar, Auteur ; Mélanie Arab-Sedze, Auteur ; J. Champion, Auteur ; Marc Pierrot-Deseilligny , Auteur ; Essam Heggy, Auteur ; Stéphane Jacquemoud, Auteur Année de publication : 2013 Article en page(s) : pp 1 - 11 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] anisotropie
[Termes IGN] appariement d'images
[Termes IGN] lave
[Termes IGN] microtopographie
[Termes IGN] Piton de la Fournaise (volcan)
[Termes IGN] Réunion, île de la
[Termes IGN] rugosité
[Termes IGN] volcanRésumé : (auteur) We present a rapid in situ photogrammetric method to characterize surface roughness by taking overlapping photographs of a scene. The method uses a single digital camera to create a high-resolution digital terrain model (pixel size of ~1.32 mm) by means of a free open-source stereovision software. It is based on an auto-calibration process, which calculates the 3D geometry of the images, and an efficient multi-image correlation algorithm. The method is successfully applied to four different volcanic surfaces—namely, a′a lava flows, pahoehoe lava flows, slabby pahoehoe lava flows, and lapilli deposits. These surfaces were sampled in the Piton de la Fournaise volcano (Reunion Island) in October, 2011, and displayed various terrain roughnesses. Our in situ measurements allow deriving digital terrain models that reproduce the millimeter-scale height variations of the surfaces over about 12 m2. Five parameters characterizing surface topography are derived along unidirectional profiles: the root-mean-square height (ξ), the correlation length (Lc), the ratio Zs = ξ2/Lc, the tortuosity index (τ), and the fractal dimension (D). Anisotropy in the surface roughness has been first investigated using 1-m-long profiles circularly arranged around a central point. The results show that Lc, Zs and D effectively catch preferential directions in the structure of bare surfaces. Secondly, we studied the variation of these parameters as a function of the profile length by drawing random profiles from 1 to 12 m in length. We verified that ξ and Lc increase with the profile length and, therefore, are not appropriate to characterize surface roughness variation. We conclude that Zs and D are better suited to extract roughness information for multiple eruptive terrains with complex surface texture. Numéro de notice : A2013-791 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2013.03.026 Date de publication en ligne : 10/04/2013 En ligne : http://dx.doi.org/10.1016/j.rse.2013.03.026 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80084
in Remote sensing of environment > vol 135 (August 2013) . - pp 1 - 11[article]3-D mapping of a multi-layered Mediterranean forest using ALS data / António Ferraz in Remote sensing of environment, vol 121 (June 2012)
[article]
Titre : 3-D mapping of a multi-layered Mediterranean forest using ALS data Type de document : Article/Communication Auteurs : António Ferraz , Auteur ; Frédéric Bretar, Auteur ; Stéphane Jacquemoud, Auteur ; Gil Rito-Gonçalves , Auteur ; Luisa Pereira, Auteur ; Margarida Tomé, Auteur ; Paola Soares, Auteur Année de publication : 2012 Article en page(s) : pp 210 - 223 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] algorithme de décalage moyen
[Termes IGN] biomasse (combustible)
[Termes IGN] carte en 3D
[Termes IGN] cartographie 3D
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] Eucalyptus globulus
[Termes IGN] forêt méditerranéenne
[Termes IGN] hauteur de la végétation
[Termes IGN] Pinus pinaster
[Termes IGN] Portugal
[Termes IGN] régression linéaire
[Termes IGN] semis de points
[Termes IGN] strate végétaleRésumé : (Auteur) This study presents a robust approach for characterization of multi-layered forests using airborne laser scanning (ALS) data. Fuel mapping or biomass estimation requires knowing the diversity and boundaries of the forest patches, as well as their spatial pattern. This includes the thickness of the main vegetation layers, but also the spatial arrangement and size of the individual plants that compose each stratum. In order to decompose the ALS point cloud into genuine 3-D segments corresponding to individual vegetation features, such as shrubs or tree crowns, we apply a statistical approach based on the mean shift algorithm. The segments are progressively assigned to a forest layer: ground vegetation, understory or overstory. Our method relies on a single biophysically meaningful parameter, the kernel bandwidth, which is related to the local forest structure. It is validated on 44 plots of a Portuguese forest, composed mainly of eucalyptus (Eucalyptus globulus Labill.) and maritime pine (Pinus pinaster Ait.) trees. The number of detected trees varies with the dominance position: from 98.6% for the dominant trees to 12.8% for the suppressed trees. Linear regression models explain up to 70% of the variability associated with ground vegetation and understory height. Numéro de notice : A2012-730 Affiliation des auteurs : MATIS+Ext (1993-2011) Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2012.01.020 Date de publication en ligne : 03/03/2012 En ligne : https://doi.org/10.1016/j.rse.2012.01.020 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91079
in Remote sensing of environment > vol 121 (June 2012) . - pp 210 - 223[article]L-band InSAR decorrelation analysis in volcanic terrains using airborne LiDAR data and in situ measurements: The case of the Piton de la Fournaise volcano, France / Melanie Sedze (2012)PermalinkPermalinkComparing small-footprint lidar and forest inventory data for single strata biomass estimation : A case study over a multi-layered mediterranean forest / António Ferraz (2012)PermalinkEtude eXpérimentale des Formes d'Onde Lidar pour l'Observation des infrastructures et de l'environnement (EXFOLIO) : compte rendu final projet EXFOLIO TOSCA Surfaces continentales / Sylvie Durrieu (2012)Permalinkvol 66 n° 6 supplement - December 2011 - Commercial supplement issue : Advances in LIDAR data processing and applications (Bulletin de ISPRS Journal of photogrammetry and remote sensing) / Frédéric BretarPermalinkRelevance assessment of full-waveform lidar data for urban area classification / Clément Mallet in ISPRS Journal of photogrammetry and remote sensing, vol 66 n° 6 supplement (December 2011)PermalinkA marked point process for modeling lidar waveforms / Clément Mallet in IEEE Transactions on image processing, vol 19 n° 12 (December 2010)PermalinkTerrain modeling from Lidar range data in natural landscapes: a predictive and Bayesian framework / Frédéric Bretar in IEEE Transactions on geoscience and remote sensing, vol 48 n° 3 Tome 2 (March 2010)Permalink3D segmentation of forest structure using an adaptive mean shift based procedure / António Ferraz (2010)PermalinkPermalink