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Fast local adaptive multiscale image matching algorithm for remote sensing image correlation / Niccolò Dematteis in Computers & geosciences, vol 159 (February 2022)  

Public [article]  inComputers & geosciences > vol 159 (February 2022) . - n° 104988 Titre : Fast local adaptive multiscale image matching algorithm for remote sensing image correlation Type de document : Article/Communication Auteurs : Niccolò Dematteis, Auteur ; Daniele Giordan, Auteur ; Bruno Crippa, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 104988 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] appariement automatique [Termes IGN] appariement d'images [Termes IGN] données multiéchelles [Termes IGN] fonte des glaces [Termes IGN] glacier [Termes IGN] image Sentinel-MSI [Termes IGN] implémentation (informatique) [Termes IGN] Matlab [Termes IGN] Patagonie Résumé : (auteur) Various studies have shown that image correlation calculated in the space domain outperforms frequency-based methods. However, such an approach usually requires great computational efforts, making it challenging to adopt for surveying fast moving processes like glaciers, particularly over wide areas. We present a local adaptive multiscale image matching algorithm (LAMMA), which repeatedly applies image correlation on grids of increasing spatial resolution and adapts the size of the interrogation area according to the local range of displacements. LAMMA allows reducing the number of calculi of several orders of magnitude and limits the occurrence of displacement outliers. We show an example of LAMMA application on Sentinel-2 images to measure glaciers flow of the Southern Patagonian Icefield, where LAMMA's runtime was comparable to that of frequency-based correlation. LAMMA's Matlab code is freely available on GitHub. Numéro de notice : A2022-094 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1016/j.cageo.2021.104988 Date de publication en ligne : 19/11/2021 En ligne : https://doi.org/10.1016/j.cageo.2021.104988 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99528 [article]

Maps, volunteered geographic information (VGI) and the spatio-discursive construction of nature / Juan Astaburuaga in Digital Geography and Society, vol 3 (2022)  

Public [article]  inDigital Geography and Society > vol 3 (2022) . - n° 100029 Titre : Maps, volunteered geographic information (VGI) and the spatio-discursive construction of nature Type de document : Article/Communication Auteurs : Juan Astaburuaga, Auteur ; Michael E. Martin, Auteur ; Agnieszka Leszczynski, Auteur ; JC Gaillard, Auteur Année de publication : 2022 Article en page(s) : n° 100029 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse du discours [Termes IGN] cartographie collaborative [Termes IGN] données localisées des bénévoles [Termes IGN] gestion de la vie sauvage [Termes IGN] milieu naturel [Termes IGN] Patagonie [Termes IGN] représentation mentale [Vedettes matières IGN] Cartologie Résumé : (auteur) This paper interrogates the role that spatial media such as maps and Volunteered Geographic Information (VGI) play in the construction and mobilisation of representations of nature. Drawing on poststructural political ecology, critical cartography, and GIScience, this article engages maps and VGI as discursive mechanisms that solidify and convey meanings and representations of nature tied to broader strategies of commodification. Particularly, we explore how spatial media reproduces and legitimises discursive strategies that rationalise the reconciliation of economic development and conservation through nature-based tourism by producing new ways of nature commodification. Drawing on evidence from Patagonia-Aysén, Chile, this paper examines the intersections between the discourse of nature encoded within institutional tourist maps and advertisements, and within the VGI platform for travellers, TripAdvisor. This illustrative case shows, firstly, how tourist maps and advertisements have contributed to normalising a discursive construction of nature as pristine, grandiose, sublime and wild that has not only secured aesthetics as ontological qualities of nature, but also as embedded values that protect ‘nature’ as a commodity to consume. Secondly, our findings evidence that TripAdvisor emerges out of this context as content that mobilises individual perceptions of and narratives about Patagonian nature that is already mediated by this dominant discourse. This dynamic suggests that VGI constitutes a new form of discursive power that digitally reproduces and mobilises a dominant discourse of nature, (re)producing what we term ‘discursive digital nature’. Numéro de notice : A2022-140 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1016/j.diggeo.2022.100029 Date de publication en ligne : 22/01/2022 En ligne : https://doi.org/10.1016/j.diggeo.2022.100029 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99772 [article]

Clinal variation along precipitation gradients in Patagonian temperate forests: unravelling demographic and selection signatures in three Nothofagus spp. / Carolina Soliani in Annals of Forest Science, Vol 77 n° 1 (March 2020)  

Public [article]  inAnnals of Forest Science > Vol 77 n° 1 (March 2020) . - 17 p. Titre : Clinal variation along precipitation gradients in Patagonian temperate forests: unravelling demographic and selection signatures in three Nothofagus spp. Type de document : Article/Communication Auteurs : Carolina Soliani, Auteur ; Maria Marta Azpilicueta, Auteur ; Maria Veronica Arana, Auteur ; Paula Marchelli, Auteur Année de publication : 2020 Article en page(s) : 17 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse diachronique [Termes IGN] forêt tempérée [Termes IGN] génétique forestière [Termes IGN] Nothofagus (genre) [Termes IGN] nothofagus pumilio [Termes IGN] Patagonie [Termes IGN] Pléistocène [Termes IGN] précipitation [Termes IGN] prévision [Termes IGN] sécheresse [Termes IGN] stress hydrique [Vedettes matières IGN] Végétation et changement climatique Résumé : (auteur) Key message: Past demographic changes and current selection pressures determine the genetic variation displayed by Nothofagus species along rainfall gradients. Based on the diversity trends observed at candidate genes associated to drought stress, we inferred a differential species’ adaptive potential. Context: Clinal genetic variation in natural populations could reflect either recent demographic history or the evolution of adapted genotypes along heterogeneous environments. Aims: We describe genetic variation patterns in three Nothofagus species of South American temperate forests, growing along steep rainfall gradients. Our hypothesis is that the selection pressure along this gradient reinforces the genetic structure previously shaped by Pleistocene climate oscillations. Methods: We screened variation along gradients at putative adaptive markers: candidate genes involved in response to drought, and EST-SSRs linked to drought stress genes. Genomic SSRs (gSSRs) were used to decouple the incidence of demographic events in the genetic structure. Results: Genetic diversity at SSRs agreed with the putative location of cryptic Pleistocene refugia in Nothofagus. In addition, each species showed different trends for nucleotide diversity at candidate genes. Unbiased heterozygosity significantly correlated with precipitation at EST-SSRs in Nothofagus nervosa. We found evidences of balancing selection and several SNPs departed from neutral expectations. Conclusions: Nothofagus genetic variability shows a strong imprint of demographic changes that reveals refugia location for the species during Pleistocene. This variability is modelled by environmental conditions across natural gradients, which impose selection pressure at genome regions related to stress response, providing clues about inter-specific differences in adaptive potential to water deficit. Numéro de notice : A2020-032 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-019-0908-x Date de publication en ligne : 10/01/2020 En ligne : https://doi.org/10.1007/s13595-019-0908-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94489 [article]

Photogrammetric techniques for the determination of spatio-temporal velocity fields at glaciar San Rafael, Chile / Hans-Gerd Maas in Photogrammetric Engineering & Remote Sensing, PERS, vol 79 n° 3 (March 2013)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 79 n° 3 (March 2013) . - pp 299 - 306 Titre : Photogrammetric techniques for the determination of spatio-temporal velocity fields at glaciar San Rafael, Chile Type de document : Article/Communication Auteurs : Hans-Gerd Maas, Auteur ; G. Casasa, Auteur ; et al., Auteur Année de publication : 2013 Article en page(s) : pp 299 - 306 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques [Termes IGN] analyse spatio-temporelle [Termes IGN] champ de vitesse [Termes IGN] Chili [Termes IGN] géoréférencement [Termes IGN] glacier [Termes IGN] image terrestre [Termes IGN] Patagonie [Termes IGN] positionnement par GPS [Termes IGN] séquence d'images Résumé : (Auteur) Glaciar San Rafael in the Northern Patagonia Icefield, with a length of 46 km and an ice area of 722 km2, is the lowest latitude tidewater outlet glacier in the world and one of the fastest and most productive glaciers in southern South America in terms of iceberg flux. Spatio-temporal velocity fields in the region of the glacier front were determined from monoscopic terrestrial image sequences recorded by an inter-vallometer mode high-resolution digital camera over several days. In these image sequences, a large number of glacier surface points were tracked by subpixel accuracy feature tracking techniques. Scaling and georeferencing of the trajectories obtained from image space tracking was performed using a multi-station GPS-supported photogrammetric net-work. The technique allows for tracking hundreds of glacier surface points at a measurement accuracy in the order of one decimeter, for typical glacier movement rates, and an almost arbitrarily high temporal resolution. The results show velocities of up to 16 meters per day. Numéro de notice : A2013-106 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.79.3.299 En ligne : https://doi.org/10.14358/PERS.79.3.299 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32244 [article]