Descripteur
Documents disponibles dans cette catégorie (2740)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
Estimated location of the seafloor sources of marine natural oil seeps from sea surface outbreaks : A new "source path procedure" applied to the northern Gulf of Mexico / Zhour Najoui in Marine and Petroleum Geology, Vol 91 (March 2018)
[article]
Titre : Estimated location of the seafloor sources of marine natural oil seeps from sea surface outbreaks : A new "source path procedure" applied to the northern Gulf of Mexico Type de document : Article/Communication Auteurs : Zhour Najoui , Auteur ; Serge Riazanoff, Auteur ; Benoit Deffontaines , Auteur ; Jean-Paul Xavier, Auteur Année de publication : 2018 Projets : 3-projet - voir note / Article en page(s) : pp 190 - 201 Note générale : Bibliographie
This work is performed as a part of a PhD research program funded by VisioTerra/UPE (Université Paris-Est) and ANRT/CIFRE (N° 2013/1252).Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] fond marin
[Termes IGN] HYbrid Coordinate Ocean Model
[Termes IGN] image radar moirée
[Termes IGN] Mexique (golfe du)
[Termes IGN] modèle stochastique
[Termes IGN] pétroleRésumé : (Auteur) Marine oil reservoirs are generally characterized on the sea surface by the presence of natural oil seeps (Sea Surface outbreaks - hereafter SSO). The latter are easily evidenced with Synthetic Aperture Radar (SAR) images because of the dampening effect that oil has on the capillary and associated small gravity waves (Bragg waves). The sea surface outbreaks of oil seeps are offset from their source on the seabed (seafloor sources - SFS) by hundreds meters or even kilometres. This displacement all along the sea water column is a function of the upward velocity of the oil droplet size, and the presence of lateral marine currents. This paper proposes a Vertical Drift Model (VDM) that combines both SAR images to get the SSO and the hydrodynamic model (HYCOM) function of the oil droplet size to estimate the SFS. After oil seeps detection from SAR images, the VDM proceeds to a regression in time and space based on the upward velocity of the oil, based on Stokes law, and the hydrodynamic conditions (HYCOM) to estimate the location of the seep source on the seafloor. The upward velocity depends strongly on the unknown droplet size. We propose herein a new VDM method named "sources paths" that allows to estimate the oil seeps sources on the seafloor without a priori knowledge of the oil droplet size by finding, for each oil seep, the seafloor sources corresponding to different diameters. We call "sources path" the line that joins the seafloor sources for an oil seep. The seafloor sources ought to be at the intersection of the maximum sources paths. The methodology has been applied to the northern Gulf of Mexico where the locations of many prolific oil seep sites are well known. A first validation of the source path procedure is that the obtained SFSs correspond to the seafloor sources of oil droplets having the same diameter and seeped at different times. Another validation has been performed through the comparison of SFS locations and those of the outcropping shallow salt. This comparison shows a good correlation and suggests that the oil seeps may be situated above the allochtonous toward autochthonous salt connections. Numéro de notice : A2018-064 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.marpetgeo.2017.12.035 Date de publication en ligne : 04/01/2018 En ligne : https://doi.org/10.1016/j.marpetgeo.2017.12.035 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89404
in Marine and Petroleum Geology > Vol 91 (March 2018) . - pp 190 - 201[article]European Forest Types: toward an automated classification / Francesca Giannetti in Annals of Forest Science, vol 75 n° 1 (March 2018)
[article]
Titre : European Forest Types: toward an automated classification Type de document : Article/Communication Auteurs : Francesca Giannetti, Auteur ; Anna Barbati, Auteur ; Leone Davide Mancini, Auteur ; et al., Auteur Année de publication : 2018 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] algorithme de tri
[Termes IGN] base de règles
[Termes IGN] classification par forêts d'arbres décisionnels
[Termes IGN] classification pixellaire
[Termes IGN] Europe (géographie physique)
[Termes IGN] Fagus (genre)
[Termes IGN] milieu naturel
[Termes IGN] système d'information forestier
[Termes IGN] système d'information géographique
[Termes IGN] système expert
[Vedettes matières IGN] Inventaire forestierRésumé : (Auteur) Key message: The outcome of the present study leads to the application of a spatially explicit rule-based expert system (RBES) algorithm aimed at automatically classifying forest areas according to the European Forest Types (EFT) system of nomenclature at pan-European scale level. With the RBES, the EFT system of nomenclature can be now easily implemented for objective, replicable, and automatic classification of field plots for forest inventories or spatial units (pixels or polygons) for thematic mapping.
Context: Forest Types classification systems are aimed at stratifying forest habitats. Since 2006, a common scheme for classifying European forests into 14 categories and 78 types (European Forest Types, EFT) exists.
Aims: This work presents an innovative method and automated classification system that, in an objective and replicable way, can accurately classify a given forest habitat according to the EFT system of nomenclature.
Methods: A rule-based expert system (RBES) was adopted as a transparent approach after comparison with the well-known Random Forest (RF) classification system. The experiment was carried out based on the information acquired in the field in 2010 ICP level I plots in 17 European countries. The accuracy of the automated classification is evaluated by comparison with an independent classification of the ICP plots into EFT carried out during the BioSoil project field survey. Finally, the RBES automated classifier was tested also for a pixel-based classification of a pan-European distribution map of beech-dominated forests.
Results: The RBES successfully classified 94% of the plots, against a 92% obtained with RF. When applied to the mapped domain, the accuracy obtained with the RBES for the beech forest map classification was equal to 95%.
Conclusion: The RBES algorithm successfully automatically classified field plots and map pixels on the basis of the EFT system of nomenclature. The EFT system of nomenclature can be now easily and objectively implemented in operative transnational European forest monitoring programs.Numéro de notice : A2018-318 Affiliation des auteurs : non IGN Thématique : FORET/GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-017-0674-6 Date de publication en ligne : 03/01/2018 En ligne : https://doi.org/10.1007/s13595-017-0674-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90450
in Annals of Forest Science > vol 75 n° 1 (March 2018)[article]Important LiDAR metrics for discriminating forest tree species in Central Europe / Yifang Shi in ISPRS Journal of photogrammetry and remote sensing, vol 137 (March 2018)
[article]
Titre : Important LiDAR metrics for discriminating forest tree species in Central Europe Type de document : Article/Communication Auteurs : Yifang Shi, Auteur ; Tiejun Wang, Auteur ; Andrew K. Skidmore, Auteur ; Marco Heurich, Auteur Année de publication : 2018 Article en page(s) : pp 163 - 174 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] Allemagne
[Termes IGN] arbre (flore)
[Termes IGN] classification par forêts d'arbres décisionnels
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] Europe centrale
[Termes IGN] forêt tempérée
[Termes IGN] morphologie mathématiqueRésumé : (Auteur) Numerous airborne LiDAR-derived metrics have been proposed for classifying tree species. Yet an in-depth ecological and biological understanding of the significance of these metrics for tree species mapping remains largely unexplored. In this paper, we evaluated the performance of 37 frequently used LiDAR metrics derived under leaf-on and leaf-off conditions, respectively, for discriminating six different tree species in a natural forest in Germany. We firstly assessed the correlation between these metrics. Then we applied a Random Forest algorithm to classify the tree species and evaluated the importance of the LiDAR metrics. Finally, we identified the most important LiDAR metrics and tested their robustness and transferability. Our results indicated that about 60% of LiDAR metrics were highly correlated to each other (|r| > 0.7). There was no statistically significant difference in tree species mapping accuracy between the use of leaf-on and leaf-off LiDAR metrics. However, combining leaf-on and leaf-off LiDAR metrics significantly increased the overall accuracy from 58.2% (leaf-on) and 62.0% (leaf-off) to 66.5% as well as the kappa coefficient from 0.47 (leaf-on) and 0.51 (leaf-off) to 0.58. Radiometric features, especially intensity related metrics, provided more consistent and significant contributions than geometric features for tree species discrimination. Specifically, the mean intensity of first-or-single returns as well as the mean value of echo width were identified as the most robust LiDAR metrics for tree species discrimination. These results indicate that metrics derived from airborne LiDAR data, especially radiometric metrics, can aid in discriminating tree species in a mixed temperate forest, and represent candidate metrics for tree species classification and monitoring in Central Europe. Numéro de notice : A2018-080 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2018.02.002 Date de publication en ligne : 07/02/2018 En ligne : https://doi.org/10.1016/j.isprsjprs.2018.02.002 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89442
in ISPRS Journal of photogrammetry and remote sensing > vol 137 (March 2018) . - pp 163 - 174[article]Réservation
Réserver ce documentExemplaires(3)
Code-barres Cote Support Localisation Section Disponibilité 081-2018031 RAB Revue Centre de documentation En réserve L003 Disponible 081-2018033 DEP-EXM Revue LASTIG Dépôt en unité Exclu du prêt 081-2018032 DEP-EAF Revue Nancy Dépôt en unité Exclu du prêt Kinematic-PPP using single/dual frequency observations from (GPS, GLONASS and GPS/GLONASS) constellations for hydrography / Ashraf Farah in Artificial satellites, vol 53 n° 1 (March 2018)
[article]
Titre : Kinematic-PPP using single/dual frequency observations from (GPS, GLONASS and GPS/GLONASS) constellations for hydrography Type de document : Article/Communication Auteurs : Ashraf Farah, Auteur Année de publication : 2018 Article en page(s) : pp 37 - 46 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Assouan
[Termes IGN] données GLONASS
[Termes IGN] données GPS
[Termes IGN] Nil (fleuve)
[Termes IGN] positionnement cinématique
[Termes IGN] positionnement par GLONASS
[Termes IGN] positionnement par GPS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] récepteur bifréquence
[Termes IGN] récepteur monofréquenceRésumé : (auteur) Global Positioning System (GPS) technology is ideally suited for inshore and offshore positioning because of its high accuracy and the short observation time required for a position fix. Precise point positioning (PPP) is a technique used for position computation with a high accuracy using a single GNSS receiver. It relies on highly accurate satellite position and clock data that can be acquired from different sources such as the International GNSS Service (IGS). PPP precision varies based on positioning technique (static or kinematic), observations type (single or dual frequency) and the duration of observations among other factors. PPP offers comparable accuracy to differential GPS with safe in cost and time. For many years, PPP users depended on GPS (American system) which considered the solely reliable system. GLONASS's contribution in PPP techniques was limited due to fail in maintaining full constellation. Yet, GLONASS limited observations could be integrated into GPS-based PPP to improve availability and precision. As GLONASS reached its full constellation early 2013, there is a wide interest in PPP systems based on GLONASS only and independent of GPS. This paper investigates the performance of kinematic PPP solution for the hydrographic applications in the Nile river (Aswan, Egypt) based on GPS, GLONASS and GPS/GLONASS constellations. The study investigates also the effect of using two different observation types; single-frequency and dual frequency observations from the tested constellations. Numéro de notice : A2018-174 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.2478/arsa-2018-0004 Date de publication en ligne : 24/03/2018 En ligne : https://doi.org/10.2478/arsa-2018-0004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89814
in Artificial satellites > vol 53 n° 1 (March 2018) . - pp 37 - 46[article]Utilisation de la photogrammétrie numérique pour la modélisation de fonds mobiles de modèles physiques / Maxime Cartier Xatard in XYZ, n° 154 (mars - mai 2018)
[article]
Titre : Utilisation de la photogrammétrie numérique pour la modélisation de fonds mobiles de modèles physiques Type de document : Article/Communication Auteurs : Maxime Cartier Xatard, Auteur Année de publication : 2018 Article en page(s) : pp 22 - 30 Langues : Français (fre) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] Agisoft Photoscan
[Termes IGN] CloudCompare
[Termes IGN] lever bathymétrique
[Termes IGN] Loire (bassin)
[Termes IGN] modélisation de prise de vue
[Termes IGN] photogrammétrie sous-marine
[Termes IGN] plan de vol
[Termes IGN] rééchantillonnage
[Termes IGN] réfraction de l'eau
[Termes IGN] sédiment
[Termes IGN] semis de points
[Termes IGN] surface de l'eauRésumé : (Auteur) La photogrammétrie est un domaine en plein essor. L'arrivée des drones sur le marché a permis un grand bond en avant dans le progrès des techniques d'acquisition et ainsi diversifier l'utilisation traditionnelle qui lui était réservé jusqu'à présent. La question se pose aujourd'hui quant à son utilisation en bathymétrie. Ce projet de fin d'étude au sein de la CNR s'articule suivant deux axes : l'acquisition et le traitement des données. Une solution d'acquisition photogrammétrique à travers l'eau et adaptée à l'échelle d'un modèle physique est d'abord développé. Dans un second temps, une chaîne de traitement des photos et un algorithme de correction de la réfraction sur les données sont combinés pour obtenir des résultats utilisables en aval pour des études sédimentaires. Des protocoles pour chaque étape sont alors rédigés pour les futures études. Numéro de notice : A2018-084 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89454
in XYZ > n° 154 (mars - mai 2018) . - pp 22 - 30[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 112-2018011 RAB Revue Centre de documentation En réserve L003 Disponible Caractérisation et qualification de Modèles Numériques de Surfaces (MNS) - Analyse de la cohérence avec des masques d’eau / Guillaume Sutter (2018)PermalinkContribution actuelle de la calotte Antarctique à la variation du niveau marin / Clémence Chupin (2018)PermalinkDétermination du géopotentiel à haute résolution spatiale : apport des horloges atomiques et des algorithmes génétiques / Guillaume Lion (2018)PermalinkDétermination d’un modèle géopotentiel à haute résolution en zone littorale aidé par des mesures d’horloges atomiques / Hugo Lecomte (2018)PermalinkDéveloppement et mise en ligne d’un portail cartographique pour la continuité écologique / Juliette Delannoy (2018)PermalinkEvaluation des performances des modèles numérique d’élévation issus de l’imagerie tri-stéréo Pléiades pour le suivi de l’évolution morphologique des dunes littorales / Mannaïg L'haridon (2018)PermalinkPermalinkPermalinkGeometric multi-wavelet total variation for SAR image time series analysis / Abdourrahmane M. Atto (2018)PermalinkPermalink