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Improving the unsupervised mapping of riparian bugweed in commercial forest plantations using hyperspectral data and LiDAR / Kabir Peerbhay in Geocarto international, vol 36 n° 4 ([01/03/2021])
[article]
Titre : Improving the unsupervised mapping of riparian bugweed in commercial forest plantations using hyperspectral data and LiDAR Type de document : Article/Communication Auteurs : Kabir Peerbhay, Auteur ; Onisimo Mutanga, Auteur ; Romano Lottering, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 465 - 480 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] carte de la végétation
[Termes IGN] classification non dirigée
[Termes IGN] classification par forêts d'arbres décisionnels
[Termes IGN] détection d'objet
[Termes IGN] données lidar
[Termes IGN] espèce exotique envahissante
[Termes IGN] forêt ripicole
[Termes IGN] image AISA+
[Termes IGN] image hyperspectrale
[Termes IGN] précision cartographique
[Termes IGN] semis de pointsRésumé : (auteur) Accurate spatial information on the location of invasive alien plants (IAPs) in riparian environments is critical to fulfilling a comprehensive weed management regime. This study aimed to automatically map the occurrence of riparian bugweed (Solanum mauritianum) using airborne AISA Eagle hyperspectral data (393 nm–994 nm) in conjunction with LiDAR derived height. Utilising an unsupervised random forest (RF) classification approach and Anselin local Moran’s I clustering, results indicate that the integration of LiDAR with minimum noise fraction (MNF) produce the best detection rate (DR) of 88%, the lowest false positive rate (FPR) of 7.14% and an overall mapping accuracy of 83% for riparian bugweed. In comparison, utilising the original hyperspectral wavebands with and without LiDAR produced lower DRs and higher FPRs with overall accuracies of 79% and 68% respectively. This research demonstrates the potential of combining spectral information with LiDAR to accurately map IAPs using an automated unsupervised RF anomaly detection framework. Numéro de notice : A2021-163 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2019.1614101 Date de publication en ligne : 10/06/2019 En ligne : https://doi.org/10.1080/10106049.2019.1614101 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97084
in Geocarto international > vol 36 n° 4 [01/03/2021] . - pp 465 - 480[article]Monitoring the coastal changes of the Po river delta (Northern Italy) since 1911 using archival cartography, multi-temporal aerial photogrammetry and LiDAR data: implications for coastline changes in 2100 A.D. / Massimo Fabris in Remote sensing, Vol 13 n° 3 (February 2021)
[article]
Titre : Monitoring the coastal changes of the Po river delta (Northern Italy) since 1911 using archival cartography, multi-temporal aerial photogrammetry and LiDAR data: implications for coastline changes in 2100 A.D. Type de document : Article/Communication Auteurs : Massimo Fabris, Auteur Année de publication : 2021 Article en page(s) : n° 529 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] analyse spatio-temporelle
[Termes IGN] archives
[Termes IGN] cartographie ancienne
[Termes IGN] détection de changement
[Termes IGN] données lidar
[Termes IGN] données multitemporelles
[Termes IGN] modèle numérique de terrain
[Termes IGN] montée du niveau de la mer
[Termes IGN] photogrammétrie aérienne
[Termes IGN] Pô (delta)
[Termes IGN] semis de points
[Termes IGN] surveillance du littoral
[Termes IGN] trait de côteRésumé : (auteur) Interaction between land subsidence and sea level rise (SLR) increases the hazard in coastal areas, mainly for deltas, characterized by flat topography and with great social, ecological, and economic value. Coastal areas need continuous monitoring as a support for human intervention to reduce the hazard. Po River Delta (PRD, northern Italy) in the past was affected by high values of artificial land subsidence: even if at low rates, anthropogenic settlements are currently still in progress and produce an increase of hydraulic risk due to the loss of surface elevation both of ground and levees. Many authors have provided scenarios for the next decades with increased flooding in densely populated areas. In this work, a contribution to the understanding future scenarios based on the morphological changes that occurred in the last century on the PRD coastal area is provided: planimetric variations are reconstructed using two archival cartographies (1911 and 1924), 12 multi-temporal high-resolution aerial photogrammetric surveys (1933, 1944, 1949, 1955, 1962, 1969, 1977, 1983, 1990, 1999, 2008, and 2014), and four LiDAR (light detection and ranging) datasets (acquired in 2006, 2009, 2012, and 2018): obtained results, in terms of emerged surfaces variations, are linked to the available land subsidence rates (provided by leveling, GPS—global positioning system, and SAR—synthetic aperture radar data) and to the expected SLR values, to perform scenarios of the area by 2100: results of this work will be useful to mitigate the hazard by increasing defense systems and preventing the risk of widespread flooding. Numéro de notice : A2021-199 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/rs13030529 Date de publication en ligne : 02/02/2021 En ligne : https://doi.org/10.3390/rs13030529 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97151
in Remote sensing > Vol 13 n° 3 (February 2021) . - n° 529[article]Uncertainties and errors in algorithms for elevation gradients / Dong Shi in International journal of geographical information science IJGIS, vol 35 n° 2 (February 2021)
[article]
Titre : Uncertainties and errors in algorithms for elevation gradients Type de document : Article/Communication Auteurs : Dong Shi, Auteur ; Qinke Yang, Auteur ; Qifeng Zhu, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 296 - 320 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] analyse comparative
[Termes IGN] erreur
[Termes IGN] filtrage du bruit
[Termes IGN] fonction harmonique
[Termes IGN] gradient d'altitude
[Termes IGN] gradient de pente
[Termes IGN] incertitude géométrique
[Termes IGN] modèle numérique de surface
[Termes IGN] modèle numérique de terrainRésumé : (auteur) Elevation gradients are primary components of slope and aspect. Significant concerns remain when computing gradients if noise (perturbing non-DEM data) is present. There is still a need to find ways to balance accuracy of the gradient and stability to noise for specific types of DEM. In this study, six algorithms are compared using four DEMs and analyzed for stability to base level DEM noise and added random noise. Theoretical stability and accuracy of the formulae are analyzed using harmonic (frequency or spatial scale) response. The results provide a basis to determine the most appropriate algorithm for different situations. They show that: (1) the set (Evans-Young (EY), Sharpnack (Sp), Sobel (Sb)) has a better stability to noise ratio than the set (Zevenbergen (Z), Florinsky (F), Horn (H)). EY has the smoothest surface and the highest stability to noise ratio. If stability is the primary measure in mid-frequencies, EY is a good choice. (2) Sb is good because of its accuracy in mid to high frequencies. Out to the highest frequencies, Sb is the best. (3) F has potential but should not be used with very high-frequency noise. (4) H and Z should not be used when there is substantial noise. Numéro de notice : A2021-039 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2020.1766047 Date de publication en ligne : 14/05/2020 En ligne : https://doi.org/10.1080/13658816.2020.1766047 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96748
in International journal of geographical information science IJGIS > vol 35 n° 2 (February 2021) . - pp 296 - 320[article]
Titre : 3D object detection using lidar point clouds and 2D image object detection Type de document : Mémoire Auteurs : Topi Miekkala, Auteur Editeur : Tampere [Finlande] : Tampere University Année de publication : 2021 Importance : 67 p. Format : 21 x 30 cm Note générale : bibliographie
Master of Science Thesis, Automation EngineeringLangues : Français (fre) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] apprentissage profond
[Termes IGN] détection d'objet
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] fusion de données
[Termes IGN] image 2D
[Termes IGN] navigation autonome
[Termes IGN] objet 3D
[Termes IGN] piéton
[Termes IGN] point d'intérêt
[Termes IGN] segmentation
[Termes IGN] semis de points
[Termes IGN] temps réel
[Termes IGN] vision par ordinateurRésumé : (auteur) This master thesis is about the environmental sensing of an automated vehicle, and its ability to recognize objects of interest such as other road users including pedestrians and other vehicles. Automated driving is a popular and growing field of research, and the continuous increase in the demand of self-driving vehicles requires manufacturers to constantly improve the safety and environmental sensing capabilities of their vehicles. Deep learning neural networks and sensor data fusion are significant tools in the development of detection algorithms of automated vehicles. This thesis presents a method combining neural networks and sensor data fusion to implement 3D object detection into a self-driving car. The method uses an onboard camera sensor and a state of the art 2D image object detector YOLO v4, combining its detections with the data of a lidar sensor, which produces dense point clouds of its environment. These point clouds can be used to estimate distances and locations of surrounding targets. Using inter-sensor calibration between the camera and the lidar, the 3D points outputted by the lidar can be projected on a 2D image, therefore allowing the 3D location estimation of 2D objects detected in an image. The thesis first presents the research questions and the theoretical methods used to implement the algorithm. Some background on automated driving is also presented, followed by the specific research environment and vehicle used in this thesis. The thesis also presents the software implementations and vehicle system integration steps needed to implement everything into a self-driving car to achieve a real-time 3D object detection system. The results of this thesis show that using sensor data fusion, such a system can be integrated fully into a self-driving vehicle, and the processing times of the algorithm can be kept at a real-time rate. Note de contenu : 1- Introduction
2- Methods for sensor data and object detection
3- Autonomous driving and environmental sensing
4- Experiments
5- Evaluation
6- ConclusionNuméro de notice : 28594 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Mémoire masters divers En ligne : https://trepo.tuni.fi/handle/10024/132285 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99323 3D urban scene understanding by analysis of LiDAR, color and hyperspectral data / David Duque-Arias (2021)
Titre : 3D urban scene understanding by analysis of LiDAR, color and hyperspectral data Type de document : Thèse/HDR Auteurs : David Duque-Arias, Auteur ; Beatriz Marcotegui, Directeur de thèse ; Jean-Emmanuel Deschaud, Directeur de thèse Editeur : Paris : Université Paris Sciences et Lettres Année de publication : 2021 Importance : 191 p. Format : 21 x 30 cm Note générale : bibliographie
Thèse de Doctorat de l'Université PSL, Spécialité : Morphologie MathématiqueLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] analyse de scène 3D
[Termes IGN] apprentissage profond
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] graphe
[Termes IGN] image hyperspectrale
[Termes IGN] image optique
[Termes IGN] modélisation géométrique de prise de vue
[Termes IGN] monde virtuel
[Termes IGN] morphologie mathématique
[Termes IGN] navigation autonome
[Termes IGN] scène urbaine
[Termes IGN] segmentation sémantique
[Termes IGN] semis de points
[Termes IGN] traitement d'imageIndex. décimale : THESE Thèses et HDR Résumé : (auteur) Point clouds have attracted the interest of the research community over the last years. Initially, they were mostly used for remote sensing applications. More recently, thanks to the development of low-cost sensors and the publication of some open source libraries, they have become very popular and have been applied to a wider range of applications. One of them is the autonomous vehicle where many efforts have been made in the last century to make it real. A very important bottleneck nowadays for the autonomous vehicle is the evaluation of the proposed algorithms. Due to the huge number of possible scenarios, it is not feasible to perform it in real life. An alternative is to simulate virtual environments where all possible configurations can be set up beforehand. However, they are not as realistic as the real world is. In this thesis, we studied the pertinence of including hyperspectral images in the creation of new virtual environments. Furthermore, we proposed new methods to improve 3D scene understanding for autonomous vehicles. During this research, we addressed the following topics. Firstly, we analyzed the spectrum in color and hyperspectral images because it provides a description about the electromagnetic radiation at different frequencies. Some applications rely only on visible colors. In other cases, such as the characterization of materials, the study of the invisible range is required. For this purpose, we proposed a simplified spectrum representation that preserves its diversity, the Graph-based color lines (GCL) model. Secondly, we studied the integration of hyperspectral images, color images and point clouds in urban scenes. The analysis was carried out by using the data acquired during this thesis in the context of the REPLICA project FUI 24. We inspected spectral signatures of different objects and reflectance histograms of the images. The obtained results demonstrate that urban scenes are challenging scenarios for current technology of hyperspectral cameras due to the presence of uncontrolled light conditions and moving actors. Thirdly, we worked with 3D point clouds from urban scenes that have proved to be a reliable type of data, much less sensitive to illumination variations than cameras. They are more accurate than color images and permit to obtain precise 3D models of urban environments. Deep learning techniques are very popular in this domain. A key element of these techniques is the loss function that drives the optimization process. We proposed two new loss functions to perform semantic segmentation tasks: power Jaccard loss and hierarchical loss. They obtained a higher performance in evaluated scenarios than classical losses not only in 3D point clouds but also in color and gray scale images. Moreover, we proposed a new dataset (Paris Carla 3D Dataset) composed of synthetic and real point clouds from urban scenes. It is expected to be used by the research community for different automatic tasks such as semantic segmentation, instance segmentation and scene completion. Finally, we conducted a detailed analysis of the influence of RGB features in semantic segmentation of urban point clouds. We compared several training scenarios and identified that color systematically improves the performance in certain classes. It demonstrates that including a more detailed description of the spectrum, when the hyperspectral cameras technology increases its sensitivity, can be useful to improve scene description of urban scenes. Note de contenu : 1- Introduction
2- Data used in this thesis
3- Graph based color lines (GCL)
4- Study of REPLICA data
5- Power Jaccard losses for semantic segmentation
6- Segmentation of point clouds
7- Conclusions and perspectivesNuméro de notice : 28464 Affiliation des auteurs : non IGN Thématique : IMAGERIE/MATHEMATIQUE/URBANISME Nature : Thèse française Note de thèse : Thèse de Doctorat : Morphologie Mathématique : Paris sciences et lettres : 2021 Organisme de stage : Centre de Morphologie Mathématique DOI : sans En ligne : https://pastel.hal.science/tel-03434199/ Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99076 Amélioration et adaptation du protocole de mesure d’empreintes d’abrasion par photogrammétrie / Hiba Sayeh (2021)PermalinkAn efficient representation of 3D buildings: application to the evaluation of city models / Oussama Ennafii (2021)PermalinkApport des méthodes : imagerie drone, LiDAR et imagerie hyperspectrale pour l’étude du littoral vendéen / Mathis Baudis (2021)PermalinkApport de la photogrammétrie dans la documentation et le suivi d’une tranchée archéologique / Iris Lucas (2021)PermalinkApport de la photogrammétrie et de l’intelligence artificielle à la détection des zones amiantées sur les fronts rocheux / Philippe Caudal (2021)PermalinkAutomatic object extraction from airborne laser scanning point clouds for digital base map production / Elyta Widyaningrum (2021)PermalinkContributions to graph-based hierarchical analysis for images and 3D point clouds / Leonardo Gigli (2021)PermalinkDéveloppement d’outils d’exploitation des archives photographiques aériennes de l’IGN pour caractériser l’évolution pluridécennale du littoral sur l’île de la Réunion / Adinane Oladjidé Ayichemi (2021)PermalinkFusion of ground penetrating radar and laser scanning for infrastructure mapping / Dominik Merkle in Journal of applied geodesy, vol 15 n° 1 (January 2021)PermalinkGeometric and semantic joint approach for the reconstruction of digital models of buildings / Pierre-Alain Langlois (2021)Permalink