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Trajectory and image-based detection and identification of UAV / Yicheng Liu in The Visual Computer, vol 37 n° 7 (July 2021)
[article]
Titre : Trajectory and image-based detection and identification of UAV Type de document : Article/Communication Auteurs : Yicheng Liu, Auteur ; Luchuan Liao, Auteur ; Hao Wu, Auteur ; et al., Auteur Année de publication : 2021 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] Aves
[Termes IGN] caméra de surveillance PTZ
[Termes IGN] classification par réseau neuronal convolutif
[Termes IGN] détection d'objet
[Termes IGN] drone
[Termes IGN] forme caractéristique
[Termes IGN] interférence
[Termes IGN] objet mobile
[Termes IGN] reconnaissance de formes
[Termes IGN] trajectoire (véhicule non spatial)Résumé : (auteur) Much more attentions have been attracted to the inspection and prevention of unmanned aerial vehicle (UAV) in the wake of increasing high frequency of security accident. Many factors like the interferences and the small fuselage of UAV pose challenges to the timely detection of the UAV. In our work, we present a system that is capable of detecting, recognizing, and tracking an UAV using single camera automatically. For our method, a single pan–tilt–zoom (PTZ) camera detects flying objects and gets their trajectories; then, the trajectory identified as a UAV guides the camera and PTZ to capture the detailed region image of the target. Therefore, the images can be classified into the UAV and interference classes (such as birds) by the convolution neural network classifier trained with our image dataset. For the target recognized as a UAV with the double verification, the radio jammer emits the interferential radio to disturb its control radio and GPS. This system could be applied in some complex environment where many birds and UAV appear simultaneously. Numéro de notice : A2021-541 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1007/s00371-020-01937-y Date de publication en ligne : 29/07/2020 En ligne : https://doi.org/10.1007/s00371-020-01937-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98020
in The Visual Computer > vol 37 n° 7 (July 2021)[article]Discovery of new colonies by Sentinel2 reveals good and bad news for emperor penguins / Peter T. Fretwell in Remote sensing in ecology and conservation, vol 7 n° 2 (June 2021)
[article]
Titre : Discovery of new colonies by Sentinel2 reveals good and bad news for emperor penguins Type de document : Article/Communication Auteurs : Peter T. Fretwell, Auteur ; Philip N. Trathan, Auteur Année de publication : 2021 Article en page(s) : pp 139 - 153 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] Antarctique
[Termes IGN] Aves
[Termes IGN] image Sentinel-MSIMots-clés libres : manchot empereur Aptenodytes forsteri Résumé : (auteur) The distribution of emperor penguins is circumpolar, with 54 colony locations currently reported of which 50 are currently extant as of 2019. Here we report on eight newly discovered colonies and confirm the rediscovery of three breeding sites, only previously reported in the era before Very High Resolution satellite imagery was available, making a total of 61 breeding locations. This represents an increase of ~20% in the number of breeding sites, but, as most of the colonies appear to be small, they may only increase the total population by around 5–10%. The discoveries have been facilitated by the use of Sentinel2 satellite imagery, which has a higher resolution and more efficient search mechanism than the Landsat data previously used to search for colonies. The small size of these new colonies indicates that considerations of reproductive output in relation to metabolic rate during huddling is likely to be of interest. Some of the colonies exist in offshore habitats, something not previously reported for emperor penguins. Comparison with recent modelling results show that the geographic locations of all the newly found colonies are in areas likely to be highly vulnerable under business-as-usual greenhouse gas emissions scenarios, suggesting that population decreases for the species will be greater than previously thought. Numéro de notice : A2021-732 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1002/rse2.176 Date de publication en ligne : 04/08/2020 En ligne : https://doi.org/10.1002/rse2.176 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98678
in Remote sensing in ecology and conservation > vol 7 n° 2 (June 2021) . - pp 139 - 153[article]Canopy openness and exclusion of wild ungulates act synergistically to improve oak natural regeneration / Julien Barrere in Forest ecology and management, Vol 487 ([01/05/2021])
[article]
Titre : Canopy openness and exclusion of wild ungulates act synergistically to improve oak natural regeneration Type de document : Article/Communication Auteurs : Julien Barrere, Auteur ; Linda K. Petersson, Auteur ; Vincent Boulanger, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 118976 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] canopée
[Termes IGN] Cervidae
[Termes IGN] dynamique de la végétation
[Termes IGN] France (administrative)
[Termes IGN] gestion forestière
[Termes IGN] Quercus pedunculata
[Termes IGN] Quercus sessiliflora
[Termes IGN] régénération (sylviculture)
[Termes IGN] Suède
[Vedettes matières IGN] SylvicultureRésumé : (auteur) The recruitment of forest trees is driven by both bottom-up processes (the acquisition of resources) and top-down processes (herbivory). To initiate stand regeneration, foresters commonly reduce tree density to increase light levels for seedlings and enhance primary productivity. These changes in vegetation dynamics, however, could also influence effects of ungulate browsing, resulting in unintended consequences for forest management. Here, we assessed how effects of ungulate exclusion and canopy opening interacted to affect the regeneration of two oak species: Quercus robur and Quercus petraea. We monitored the growth and survival of oak seedlings for two to three growth seasons in paired fenced and unfenced plots under contrasting conditions of canopy openness (8% to 52%) at five sites in southern Sweden and three sites in northeastern France. We scored browsing in the unfenced plots by the four cervids occurring in these areas (Alces alces, Capreolus capreolus, Cervus elaphus and Dama dama). Fencing increased the growth of (mostly taller) seedlings occurring in Sweden and the survival of (mostly smaller) seedlings in France. Both effects increased as canopies became more open. Browsing reduced oak seedling growth in both countries, independently of canopy openness. Canopy openness increased browsing levels in Sweden. Cervid densities did not appear to modify how fencing affected oak seedling growth and survival. In both contrasting forest environments, creating gaps tended to enhance ungulate damage on young forest stands as browsing frequency increased. We conclude that net forest regeneration reflects a subtle equilibrium between enhancing resource availability, boosting seedling growth, and limiting herbivory, which curtails seedling growth and survival. Numéro de notice : A2021-356 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2021.118976 Date de publication en ligne : 15/02/2021 En ligne : https://doi.org/10.1016/j.foreco.2021.118976 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97613
in Forest ecology and management > Vol 487 [01/05/2021] . - n° 118976[article]Streams and rural abandonment are related to the summer activity of the invasive pest Drosophila suzukii in protected European forests / Alberto Maceda-Veiga in Forest ecology and management, vol 485 ([01/04/2021])
[article]
Titre : Streams and rural abandonment are related to the summer activity of the invasive pest Drosophila suzukii in protected European forests Type de document : Article/Communication Auteurs : Alberto Maceda-Veiga, Auteur ; Sergio Albacete, Auteur ; Miguel Carles-Tolrá, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 118942 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] aire protégée
[Termes IGN] Castanea (genre)
[Termes IGN] cours d'eau
[Termes IGN] diptère
[Termes IGN] Espagne
[Termes IGN] foresterie
[Termes IGN] habitat forestier
[Termes IGN] insecte nuisible
[Termes IGN] interaction spatiale
[Termes IGN] migration rurale
[Termes IGN] structure d'un peuplement forestier
[Vedettes matières IGN] SylvicultureRésumé : (auteur) Protected native-forested areas may be occupied by fruit pests, and so, studies exploring the biotic and abiotic determinants of fruit-pest abundance in forested areas may reduce damages in crops and wild forest frugivores. The Spotted Wing Drosophila (SWD) Drosophila suzukii is an economically important fruit pest in many temperate regions around the world. During the dry summer in northwestern Spain, we assessed 24 native riparian and 32 non-riparian chestnut forest patches as non-crop habitats for the SWD. We surveyed chestnut forests in 2017 and found a positive association between spatial proximity of forest patches to streams and SWD captures, which led us to study in 2019 the stream-SWD associations in greater detail. We explored whether native-insect communities and changes in vegetation structure related to rural abandonment were associated with variation in SWD captures, while accounting for the effects of covariates, including stream distance. There were no significant associations in the riparian and non-riparian-habitat surveys between the captures of SWDs and those of native insects, including 22 families of flies and 10 families of parasitic wasps. However, captures of SWDs and of other drosophilid flies were positively related to each other and the direction of the association was reversed by stream distance, which suggests the potential role of streams in regulating interactions among non-riparian insects, including SWD. We also found correlative evidence that degraded riparian forests and the abandonment of traditional forest practices in chestnut forests may be contributing to the spread of SWD. Given the numbers of SWDs in our forest samples were similar to values in August in crop areas, it is advisable that future studies address the impacts of SWD invasion on native forest frugivores, which have been overlooked in studies of this widely distributed invasive species. Numéro de notice : A2021-265 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2021.118942 Date de publication en ligne : 30/01/2021 En ligne : https://doi.org/10.1016/j.foreco.2021.118942 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97318
in Forest ecology and management > vol 485 [01/04/2021] . - n° 118942[article]Early detection of forest stress from European spruce bark beetle attack, and a new vegetation index: Normalized distance red & SWIR (NDRS) / Langning Huo in Remote sensing of environment, Vol 255 (March 2021)
[article]
Titre : Early detection of forest stress from European spruce bark beetle attack, and a new vegetation index: Normalized distance red & SWIR (NDRS) Type de document : Article/Communication Auteurs : Langning Huo, Auteur ; Henrik J. Persson, Auteur ; Eva Lindberg, Auteur Année de publication : 2021 Article en page(s) : n° 112240 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] bande infrarouge
[Termes IGN] écho radar
[Termes IGN] houppier
[Termes IGN] image Sentinel-MSI
[Termes IGN] image Sentinel-SAR
[Termes IGN] indice de stress
[Termes IGN] indice de végétation
[Termes IGN] insecte nuisible
[Termes IGN] maladie parasitaire
[Termes IGN] Picea mariana
[Termes IGN] Scolytinae
[Termes IGN] signature spectrale
[Termes IGN] Suède
[Termes IGN] vulnérabilitéRésumé : (auteur) The European spruce bark beetle (Ips typographus [L.]) is one of the most damaging pest insects of European spruce forests. A crucial measure in pest control is the removal of infested trees before the beetles leave the bark, which generally happens before the end of June. However, stressed tree crowns do not show any significant color changes in the visible spectrum at this early-stage of infestation, making early detection difficult. In order to detect the related forest stress at an early stage, we investigated the differences in radar and spectral signals of healthy and stressed trees. How the characteristics of stressed trees changed over time was analyzed for the whole vegetation season, which covered the period before attacks (April), early-stage infestation (‘green-attacks’, May to July), and middle to late-stage infestation (August to October). The results show that spectral differences already existed at the beginning of the vegetation season, before the attacks. The spectral separability between the healthy and infested samples did not change significantly during the ‘green-attack’ stage. The results indicate that the trees were stressed before the attacks and had spectral signatures that differed from healthy ones. These stress-induced spectral changes could be more efficient indicators of early infestations than the ‘green-attack’ symptoms. In this study we used Sentinel-1 and 2 images of a test site in southern Sweden from April to October in 2018 and 2019. The red and SWIR bands from Sentinel-2 showed the highest separability of healthy and stressed samples. The backscatter from Sentinel-1 and additional bands from Sentinel-2 contributed only slightly in the Random Forest classification models. We therefore propose the Normalized Distance Red & SWIR (NDRS) index as a new index based on our observations and the linear relationship between the red and SWIR bands. This index identified stressed forest with accuracies from 0.80 to 0.88 before the attacks, from 0.80 to 0.82 in the early-stage infestation, and from 0.81 to 0.91 in middle- and late-stage infestations. These accuracies are higher than those attained by established vegetation indices aimed at ‘green-attack’ detection, such as the Normalized Difference Water Index, Ratio Drought Index, and Disease Stress Water Index. By using the proposed method, we highlight the potential of using NDRS with Sentinel-2 images to estimate forest vulnerability to European spruce bark beetle attacks early in the vegetation season. Numéro de notice : A2021-190 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.1016/j.rse.2020.112240 Date de publication en ligne : 20/01/2021 En ligne : https://doi.org/10.1016/j.rse.2020.112240 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97111
in Remote sensing of environment > Vol 255 (March 2021) . - n° 112240[article]Search for top‐down and bottom‐up drivers of latitudinal trends in insect herbivory in oak trees in Europe / Elena Valdés-Correcher in Global ecology and biogeography, vol 30 n° 3 (March 2021)PermalinkContrasting responses of habitat conditions and insect biodiversity to pest- or climate-induced dieback in coniferous mountain forests / Jérémy Cours in Forest ecology and management, vol 482 ([15/02/2021])PermalinkGeo-spatially modelling dengue epidemics in urban cities: a case study of Lahore, Pakistan / Muhammad Imran in Geocarto international, vol 36 n° 2 ([01/02/2021])PermalinkAmélioration de la gestion de l’implantation des ruches sur des propriétés régionales / Elliette Fize (2021)PermalinkCaractérisation de l’occupation spatiale des étagnes au printemps dans le Champsaur (Parc National des Écrins) : approche géomatique et biogéographique / Lucie Doudoux (2021)PermalinkInteractions between oak and cervids during the process of forest regeneration / Julien Barrere (2021)PermalinkMapping and characterizing animals’ places of interest in forest environment / Laurence Jolivet (2021)PermalinkQualification des données LiDAR GEDI pour le suivi de l’impact climatique sur la forêt de Südharz / Iris Jeuffrard (2021)PermalinkForest clear-cuts as habitat for farmland birds and butterflies / Dafne Ram in Forest ecology and management, vol 473 ([01/10/2020])PermalinkIncreasing Cervidae populations have variable impacts on habitat suitability for threatened forest plant and lichen species / James D.M. Speed in Forest ecology and management, vol 473 ([01/10/2020])PermalinkEvaluating the impact of declining tsetse fly (Glossina pallidipes) habitat in the Zambezi valley of Zimbabwe / Farai Matawa in Geocarto international, vol 35 n° 12 ([01/09/2020])PermalinkXylem anatomy of Robinia pseudoacacia L. and Quercus robur L. is differently affected by climate in a temperate alluvial forest / Paola Nola in Annals of Forest Science, Vol 77 n° 1 (March 2020)PermalinkApplication of digital image processing in automated analysis of insect leaf mines / Yee Man Theodora Cho (2020)PermalinkCattle detection and counting in UAV images based on convolutional neural networks / Wen Shao in International Journal of Remote Sensing IJRS, vol 41 n° 1 (01 - 08 janvier 2020)PermalinkThis is my spot: What are the characteristics of the trees excavated by the Black Woodpecker? A case study in two managed French forests / Camille Puverel in Forest ecology and management, vol 453 (1 December 2019)PermalinkA representativeness-directed approach to mitigate spatial bias in VGI for the predictive mapping of geographic phenomena / Guiming Zhang in International journal of geographical information science IJGIS, vol 33 n° 9 (September 2019)PermalinkDiptera in clear-felling stumps like it dry / Mats Jonsell in Scandinavian journal of forest research, vol 34 n° 8 (August 2019)PermalinkInterpreting effects of multiple, large-scale disturbances using national forest inventory data: A case study of standing dead trees in east Texas, USA / Christopher B. Edgar in Forest ecology and management, vol 437 (1 April 2019)PermalinkWood quality of black spruce and balsam fir trees defoliated by spruce budworm: A case study in the boreal forest of Quebec, Canada / Carlos Paixao in Forest ecology and management, vol 437 (1 April 2019)PermalinkA time‐geographic approach to quantifying wildlife–road interactions / Rebecca W. Loraamm in Transactions in GIS, vol 23 n° 1 (February 2019)Permalink