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Global and climate challenges, graph-based data analysis for multisource information extraction / Morgane Batelier (2022)
Titre : Global and climate challenges, graph-based data analysis for multisource information extraction Type de document : Mémoire Auteurs : Morgane Batelier, Auteur Editeur : Champs-sur-Marne : Ecole nationale des sciences géographiques ENSG Année de publication : 2022 Importance : 43 p. Format : 21 x 30 cm Note générale : Bibliographie
Mémoire de fin d'études, cycle des ingénieurs ENSG 3ème année, FRSLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] apprentissage automatique
[Termes IGN] Arctique, océan
[Termes IGN] données d'entrainement sans étiquette
[Termes IGN] glace de mer
[Termes IGN] image hyperspectrale
[Termes IGN] image Sentinel-SAR
[Termes IGN] polarimétrie radar
[Termes IGN] traitement d'image radarIndex. décimale : MPT Mémoires de fin d'études du Master Méthodes physiques en télédétection Résumé : (Auteur) During my end-of-studies internship, I worked on the development of a label propagation algorithm for remote sensing data, using Deep Learning. It was mainly applied to sea ice classification using SAR Sentinel-1 data, and to hyperspectral imaging in order to be effective to multimodal remote sensing. I started by the bibliography, during which we decided with my supervisors the method I was going to work from. Then, I worked on the algorithm implementation that was the longest phase. Finally, the last part of my work was the certification and improvement of the results using different process. Note de contenu : Introduction
1. Remote Sensing in the Arctic
1.1 Challenges of the Arctic
1.2 Sea Ice
2. Label Propagation for Deep Learning
2.1 Preliminaries
2.2 Transductive Propagation Network for Few-shot Learning
3. Multimodal Remote Sensing Data
3.1 Synthetic Aperture Radar
3.2 Hyperspectral Imaging
4. Experimental results
4.1 Datasets
4.2 Improvement Methods
4.3 Discussion and future of the algorithm
ConclusionNuméro de notice : 26935 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Mémoire de fin d'études IT Organisme de stage : Center for Integrated Remote Sensing and Forecasting for Arctic Operations CIRFA Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102059 Documents numériques
en open access
Global and climate challenges, graph-based data analysis for multisource information extraction - pdf auteurAdobe Acrobat PDF Global glacier mass change by spatiotemporal analysis of digital elevation models / Romain Hugonnet (2022)
Titre : Global glacier mass change by spatiotemporal analysis of digital elevation models Titre original : Changement de masse des glaciers à l’échelle mondiale par analyse spatiotemporelle de modèles numériques de terrain Type de document : Thèse/HDR Auteurs : Romain Hugonnet, Auteur ; Etienne Berthier, Directeur de thèse ; Daniel Farinotti, Directeur de thèse Editeur : Toulouse : Université de Toulouse 3 Paul Sabatier Année de publication : 2022 Autre Editeur : Zurich : Eidgenossische Technische Hochschule ETH - Ecole Polytechnique Fédérale de Zurich EPFZ Importance : 244 p. Format : 21 x 30 cm Note générale : bibliographie
Thèse en vue de l'obtention du Doctorat de l'Université de Toulouse, spécialité Océan, Atmosphère, ClimatLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] bilan de masse
[Termes IGN] changement climatique
[Termes IGN] cryosphère
[Termes IGN] données spatiotemporelles
[Termes IGN] fonte des glaces
[Termes IGN] glacier
[Termes IGN] image optique
[Termes IGN] MNS ASTER
[Termes IGN] modèle numérique de surface
[Termes IGN] modèle stéréoscopique
[Termes IGN] niveau de la merIndex. décimale : THESE Thèses et HDR Résumé : (auteur) The world's glaciers are shrinking rapidly, with impacts ranging from global sea-level rise and changes in freshwater availability to the alteration of cryospheric hazards. Despite significant advances during the satellite era, the monitoring of the mass changes of glaciers is still hampered by a fragmented coverage of remote sensing estimations and a poor constraint of the errors in related assessments. In this thesis, we present a globally complete and resolved estimate of glacier mass changes by spatiotemporal analysis of digital elevation models. We first develop methods based on spatiotemporal statistics to assess the accuracy and precision of digital elevation models, and to estimate time series of glacier surface elevation. In particular, we introduce a non-stationary spatial framework to estimate and propagate multi-scale spatial correlations in uncertainties of geospatial estimates. We then massively generate digital elevation models from two decades of stereo optical archives covering glaciers worldwide. From those, we estimate time series of surface elevation for all of Earth's glaciers at a resolution of 100 m during 2000-2019. Integrating these time series into volume and mass changes, we identify a significant acceleration of global glacier mass loss, as well as regionally contrasted responses that mirror decadal changes in climatic conditions. Using a large amount of independent, high-precision data, we demonstrate the validity of our analysis to yield reliable and consistent uncertainties at different scales of the spatiotemporal structure of our estimates. We expect our methods to foster robust spatiotemporal analyses, in to identify sources of biases and uncertainties in geospatial assessments. Furthermore, we anticipate our estimates to advance the understanding of the drivers that govern glacier change, and to extend our capabilities of predicting these changes at all scales. Such predictions are critically needed to design adaptive policies on the mitigation of cryospheric impacts in the context of climate change. Note de contenu : General introduction
1- Monitoring Earth’s glaciers: an observational challenge rooted in space and time
2- Analysis of accuracy and precision of digital elevation models
3- Spatiotemporal estimation of glacier surface elevation
Conclusions and outlookNuméro de notice : 24035 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse française Note de thèse : Thèse de Doctorat : Océan, Atmosphère, Climat : Toulouse 3 : 2022 Organisme de stage : LEGOS DOI : sans En ligne : https://tel.hal.science/tel-03813744 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101852 High-resolution canopy height map in the Landes forest (France) based on GEDI, Sentinel-1, and Sentinel-2 data with a deep learning approach / Martin Schwartz (2022)
Titre : High-resolution canopy height map in the Landes forest (France) based on GEDI, Sentinel-1, and Sentinel-2 data with a deep learning approach Type de document : Article/Communication Auteurs : Martin Schwartz, Auteur ; Philippe Ciais, Auteur ; Catherine Ottle, Auteur ; Aurélien de Truchis, Auteur ; Cédric Vega , Auteur ; Ibrahim Fayad, Auteur ; Martin Brandt, Auteur ; Rasmus Fensholt, Auteur ; Nicolas Baghdadi, Auteur ; François Morneau , Auteur ; David Morin, Auteur ; Dominique Guyon, Auteur ; Sylvia Dayau, Auteur ; Jean-Pierre Wigneron, Auteur Editeur : Ithaca [New York - Etats-Unis] : ArXiv - Université Cornell Année de publication : 2022 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] apprentissage profond
[Termes IGN] forêt
[Termes IGN] Global Ecosystem Dynamics Investigation lidar
[Termes IGN] hauteur des arbres
[Termes IGN] image Sentinel-MSI
[Termes IGN] image Sentinel-SAR
[Termes IGN] Landes de Gascogne
[Termes IGN] PinophytaRésumé : (auteur) In intensively managed forests in Europe, where forests are divided into stands of small size and may show heterogeneity within stands, a high spatial resolution (10 - 20 meters) is arguably needed to capture the differences in canopy height. In this work, we developed a deep learning model based on multi-stream remote sensing measurements to create a high-resolution canopy height map over the "Landes de Gascogne" forest in France, a large maritime pine plantation of 13,000 km2 with flat terrain and intensive management. This area is characterized by even-aged and mono-specific stands, of a typical length of a few hundred meters, harvested every 35 to 50 years. Our deep learning U-Net model uses multi-band images from Sentinel-1 and Sentinel-2 with composite time averages as input to predict tree height derived from GEDI waveforms. The evaluation is performed with external validation data from forest inventory plots and a stereo 3D reconstruction model based on Skysat imagery available at specific locations. We trained seven different U-net models based on a combination of Sentinel-1 and Sentinel-2 bands to evaluate the importance of each instrument in the dominant height retrieval. The model outputs allow us to generate a 10 m resolution canopy height map of the whole "Landes de Gascogne" forest area for 2020 with a mean absolute error of 2.02 m on the Test dataset. The best predictions were obtained using all available satellite layers from Sentinel-1 and Sentinel-2 but using only one satellite source also provided good predictions. For all validation datasets in coniferous forests, our model showed better metrics than previous canopy height models available in the same region. Numéro de notice : P2022-002 Affiliation des auteurs : LIF+Ext (2020- ) Thématique : FORET Nature : Preprint nature-HAL : Préprint DOI : 10.48550/arXiv.2212.10265 Date de publication en ligne : 20/12/2022 En ligne : https://doi.org/10.48550/arXiv.2212.10265 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102850 Historical shoreline analysis and field monitoring at Ennore coastal stretch along the Southeast coast of India / M. Dhananjayan in Marine geodesy, vol 45 n° 1 (January 2022)
[article]
Titre : Historical shoreline analysis and field monitoring at Ennore coastal stretch along the Southeast coast of India Type de document : Article/Communication Auteurs : M. Dhananjayan, Auteur ; S. Vasanthakumar, Auteur ; S.A. Sannasiraj, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : pp 47 - 74 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse diachronique
[Termes IGN] détection de changement
[Termes IGN] érosion côtière
[Termes IGN] image Landsat
[Termes IGN] Inde
[Termes IGN] modèle de régression
[Termes IGN] modèle de simulation
[Termes IGN] régression linéaire
[Termes IGN] surveillance du littoral
[Termes IGN] trait de côteRésumé : (auteur) A shoreline change analysis has been carried out for the coastal stretch from Ennore creek to Karungali village located along the southeast coast of India. This 15 km-long coastal stretch had undergone significant changes such as erosion and accretion concerning infrastructure developments and leading to large impact on the livelihood of the community. To assess the shoreline changes, the analysis of multi-temporal satellite images has been carried out. A historical trend is established for the study period from 1991 to 2019. The analysis has been made in three timelines considering various developing activities. There was no significant coastal infrastructure development during 1991 to 1999; however, between 1999 and 2009, a major port, pier, and a groyne field were constructed. Additionally, a port was established between 2009 and 2019. Erosion was observed on the coast from Kattupalli to Karungali at a rate of −16.85 m/yr since 2009, while the coast on the south of Ennore port is accreting at the rate of +12.43 m/yr during the same period. The near-future projection using a linear regression model shows further erosion in the coast under similar conditions. The results of this study provide a baseline data for future anthropogenic activities along this coast. Numéro de notice : A2022-037 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/01490419.2021.1992546 Date de publication en ligne : 08/11/2021 En ligne : https://doi.org/10.1080/01490419.2021.1992546 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99370
in Marine geodesy > vol 45 n° 1 (January 2022) . - pp 47 - 74[article]Investigating the role of wind disturbance in tropical forests through a forest dynamics model and satellite observations / E-Ping Rau (2022)
Titre : Investigating the role of wind disturbance in tropical forests through a forest dynamics model and satellite observations Type de document : Thèse/HDR Auteurs : E-Ping Rau, Auteur ; Jérôme Chave, Directeur de thèse Editeur : Toulouse : Université de Toulouse 3 Paul Sabatier Année de publication : 2022 Importance : 184 p. Format : 21 x 30 cm Note générale : Bibliographie
Thèse en vue de l'obtention du Doctorat de l'Université de Toulouse 3 Paul SabatierLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] biomasse forestière
[Termes IGN] canopée
[Termes IGN] chablis (sylviculture)
[Termes IGN] cyclone
[Termes IGN] forêt tropicale
[Termes IGN] Guyane française
[Termes IGN] image Sentinel-SAR
[Termes IGN] modèle dynamique
[Termes IGN] perturbation écologique
[Termes IGN] précipitation
[Termes IGN] risque naturel
[Termes IGN] sécheresse
[Termes IGN] traitement d'image radar
[Termes IGN] ventIndex. décimale : THESE Thèses et HDR Résumé : (Auteur) Natural disturbances have an important influence on the structure, composition and functioning of tropical forests and a role in the regulation of biogeochemical cycles. The frequency and intensity of natural disturbances are modified by climate change: a better knowledge of their mechanism of action is necessary to predict the consequences of this modification. Modeling allows us to evaluate the role of each of the ecological processes and their link with environmental factors. Remote sensing tools inform us about the structure and functioning of forests at large scales, and can be useful for the calibration and validation of vegetation models. In this thesis, I employed both approaches to examine how tropical forests are shaped by natural disturbances, particularly wind, which is a major disturbance factor in many tropical regions. First, I evaluated the transferability of a spatially explicit, individual-based model via sensitivity testing and calibration of global parameters. The model correctly predicts forest structure at two contrasting sites, and its response is consistent with variations in climate forcing. Calibration of a small number of key parameters was required, including the parameter controlling mortality and crown allometry. To investigate the sensitivity of the model to mortality, I implemented a wind damage module based on biophysical principles and coupled with wind speed to model forest responses to extreme wind events. With increasing disturbance level, canopy height decreased steadily but biomass showed a non-linear response. Wind intensity had a strong impact on canopy height and biomass, but not the frequency of extreme wind events. Finally, I tested whether radar data from Sentinel-1 satellites could be used to detect gaps due to natural disturbances in French Guiana. The Sentinel-1 data detected more natural gaps above 0.2 ha than the optical satellite data, and they showed a spatial pattern consistent with the optical images. The level of disturbance did not vary with altitude. We found more disturbance during dry seasons, which could be due to the delayed response of precipitation rather than the direct response of drought. In conclusion, this thesis demonstrates that the integration between modeling and remote sensing sheds light on the effects of natural disturbances on tropical forests. The resulting results can be used to study other types of disturbances and their interactions on a large scale. Note de contenu : General introduction
General methods
1: Transferability of an individual- and trait-based forest dynamics model: a test case across the tropics
1.1 Abstract
1.2 Introduction
1.3 Materials and methods
1.4 Results
1.5 Discussion
1.6 Acknowledgements and author contributions
1.7 Supplementary data
2: Wind speed controls forest structure in subtropical forests exposed to cyclones: a case study using an individual-based model
2.1 Abstract
2.2 Introduction
2.3 Material and methods
2.4 Results
2.5 Discussion
2.6 Acknowledgments and author contributions
2.7 Supplementary data
3: Detecting Natural Disturbances in Tropical Forests Using Sentinel-1 SAR Data: a Test in French Guiana
3.1 Abstract
3.2 Introduction
3.3 Methods
3.4 Results
3.5 Discussions
3.6 Acknowledgments and author contributions
3.7 Supplementary data
General discussion and conclusionsNuméro de notice : 26836 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Thèse française Note de thèse : Thèse de Doctorat : Ecologie, biodiversité et évolution : Toulouse 3 : 2022 nature-HAL : Thèse DOI : sans Date de publication en ligne : 20/06/2022 En ligne : https://tel.hal.science/tel-03699667 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101075 Latent heat flux variability and response to drought stress of black poplar: A multi-platform multi-sensor remote and proximal sensing approach to relieve the data scarcity bottleneck / Flavia Tauro in Remote sensing of environment, vol 268 (January 2022)PermalinkMapping burned areas and land-uses in Kangaroo Island using an object-based image classification framework and Landsat 8 Imagery from Google Earth Engine / Jiyu Liu in Geomatics, Natural Hazards and Risk, vol 13 (2022)PermalinkModélisation du lien entre éruptions et glissements de flancs au Piton de la Fournaise / Quentin Dumont (2022)PermalinkMonitoring forest-savanna dynamics in the Guineo-Congolian transition area of the centre region of Cameroon / Le Bienfaiteur Sagang Takougoum (2022)PermalinkMonitoring grassland dynamics by exploiting multi-modal satellite image time series / Anatol Garioud (2022)PermalinkPotentialité de la télédétection thermique pour la modélisation climatique en milieu viticole / Gwenaël Morin (2022)PermalinkPreparation of the VENµS satellite data over Israel for the input into the GRASP data treatment algorithm / Maeve Blarel (2022)PermalinkPermalinkPermalinkPermalink