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National scale mapping of larch plantations for Wales using the Sentinel-2 data archive / Suvarna M. Punalekar in Forest ecology and management, vol 501 (December-1 2021)
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Titre : National scale mapping of larch plantations for Wales using the Sentinel-2 data archive Type de document : Article/Communication Auteurs : Suvarna M. Punalekar, Auteur ; Carole Planque, Auteur ; Richard M. Lucas, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 119679 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] apprentissage automatique
[Termes IGN] arbre de décision
[Termes IGN] carte forestière
[Termes IGN] coupe rase (sylviculture)
[Termes IGN] gestion forestière
[Termes IGN] image infrarouge
[Termes IGN] image Sentinel-MSI
[Termes IGN] indice de végétation
[Termes IGN] Larix decidua
[Termes IGN] maladie phytosanitaire
[Termes IGN] modélisation de la forêt
[Termes IGN] Pays de Galles
[Termes IGN] surveillance forestièreRésumé : (auteur) Accurate spatial information regarding forest types and tree species is immensely important for efficient forest management strategies. In the UK and particularly in Wales, creating a spatial inventory of larch (Larix sps.) plantations that encompasses both the public and private forests has become one of the highest priorities of woodland management policies, particularly given the need to respond to the rapid spread of Phytophthora ramorum fungal disease. For directing disease control measures, national scale, regularly updated mapping of larch distributions is essential. In this study, we applied a ExtraTree classifier machine learning algorithm to multi-year (June 2015 and December 2019) multi-path composites of vegetation indices derived from 10 m Sentinel-2 satellite data (spectral range used in this study: 490–2190 nm) to map the extent of larch plantations across Wales. For areas identified as woody vegetation, areas under larch plantations were associated with a needle-leaved leaf type and deciduous phenology, allowing differentiation from broad-leaved deciduous and needle-leaved evergreen types. The model accuracies for validation, which included overall accuracy, producer’s and user’s accuracies, exceeded 95% and the F1-score was greater than 0.97 for all forest types. Comparison against an independent reference dataset indicated all map accuracies above 90% (F1-score higher than 0.92) with the lowest value being 90.3% for the producer’s accuracy for larch. Short wave infrared and red-edge based indices were particularly useful for discriminating larch from other forest types. Capacity for updating information on clear-felling of larch stands through annual updates of a woody mask was also introduced. The resulting maps of larch plantations for Wales are the most current for Wales covering public as well as private woodlands and can be routinely updated. The classification approach has potential to be transferred to a wider geographical area given the availability of open-source multi-year Sentienl-2 datasets and robust calibration datasets. Numéro de notice : A2021-741 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.1016/j.foreco.2021.119679 Date de publication en ligne : 20/09/2021 En ligne : https://doi.org/10.1016/j.foreco.2021.119679 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98657
in Forest ecology and management > vol 501 (December-1 2021) . - n° 119679[article]Exploring the synergy between Landsat and ASAR towards improving thematic mapping accuracy of optical EO data / Alexander Cass in Applied geomatics, vol 11 n° 3 (September 2019)
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Titre : Exploring the synergy between Landsat and ASAR towards improving thematic mapping accuracy of optical EO data Type de document : Article/Communication Auteurs : Alexander Cass, Auteur ; George P. Petropoulos, Auteur ; Konstantinos P. Ferentinos, Auteur ; et al., Auteur Année de publication : 2019 Article en page(s) : pp 277 - 288 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image mixte
[Termes IGN] carte d'occupation du sol
[Termes IGN] cartographie thématique
[Termes IGN] classification orientée objet
[Termes IGN] image Envisat-ASAR
[Termes IGN] image Landsat-TM
[Termes IGN] image optique
[Termes IGN] image radar
[Termes IGN] Pays de Galles
[Termes IGN] surface cultivéeRésumé : (Auteur) Earth Observation (EO) provides a unique means of obtaining information on land use/cover and of its changes, which is of key importance in many scientific and practical applications. EO data is already widely used, for example, in environmental practices or decision-making related to food availability and security. As such, it is imperative to examine the suitability of different EO datasets, including their synergies, in respect to their ability to create products and tools for such practices and to guide effectively such decisions. This work aims at exploring the added value of the synergistic use of optical and radar data (from the Landsat TM and Advanced Synthetic Aperture Radar (ASAR) sensors respectively). Such information can help towards improving the accuracy of land cover classifications from EO datasets. As a case study, the region of Wales in the UK has been used. Two classifications—one based on optical data alone and another one developed from the synergy of optical and RADAR datasets acquired nearly, concurrently were developed for the studied region. Evaluation of the derived land/use cover maps was performed on the basis of the confusion matrix using validation points derived from a Phase 1 habitat map of Wales. The results showed 15% increase in overall accuracy (84% from 69%) and kappa coefficient (0.81 from 0.65) using the synergistic approach over the scenario where only optical data were used in the classification. In addition, McNemar’s test was used to assess the statistical significance of the obtained results. Results of this test provided further confirmed that the use of optical data synergistically with the radar data provides more accurate land use/cover maps in comparison with the use of optical data alone. Numéro de notice : A2019-461 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s12518-019-00258-7 Date de publication en ligne : 13/04/2019 En ligne : https://doi.org/10.1007/s12518-019-00258-7 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93601
in Applied geomatics > vol 11 n° 3 (September 2019) . - pp 277 - 288[article]UAV monitoring of a largescale environmental project / Alan Roberts in GEO: Geoconnexion international, vol 15 n° 5 (May 2016)
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Titre : UAV monitoring of a largescale environmental project Type de document : Article/Communication Auteurs : Alan Roberts, Auteur Année de publication : 2016 Article en page(s) : pp 48 - 49 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] analyse comparative
[Termes IGN] drone
[Termes IGN] dune
[Termes IGN] littoral
[Termes IGN] Pays de Galles
[Termes IGN] sable
[Termes IGN] sédimentRésumé : (éditeur) A sand dune remobilisation and rejuvenation project, believed to be the largest of its kind in the UK, has been undertaken by Natural Resources Wales (NRW). Alan Roberts compares the use of UAV, LiDAR and terrestrial laser scanning surveying techniques for monitoring sediment movement. Numéro de notice : A2016-198 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80633
in GEO: Geoconnexion international > vol 15 n° 5 (May 2016) . - pp 48 - 49[article]The WISERD geoportal: A tool for the discovery, analysis and visualization of socio-economic (Meta-) data for Wales / R. Fry in Transactions in GIS, vol 16 n° 2 (April 2012)
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Titre : The WISERD geoportal: A tool for the discovery, analysis and visualization of socio-economic (Meta-) data for Wales Type de document : Article/Communication Auteurs : R. Fry, Auteur ; R. Berry, Auteur ; G. Higgs, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 105 - 124 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web
[Termes IGN] données socio-économiques
[Termes IGN] géoportail
[Termes IGN] GeoServer
[Termes IGN] logiciel libre
[Termes IGN] métadonnées
[Termes IGN] OpenLayers
[Termes IGN] Pays de Galles
[Termes IGN] PostGIS
[Termes IGN] PostgreSQLRésumé : (Auteur) The Wales Institute of Socio-Economic Research, Data and Methods (WISERD) is an interdisciplinary, cross-institutional academic research group based in Wales, UK. One of the key objectives of WISERD is to develop a spatial framework that enhances a researcher's ability to discover socio-economic research data relating to Wales with the aim of encouraging collaborative research and re-use of existing data. This article describes the development of an online geoportal designed to meet this objective. Using free and open-source software (FOSS) components and services, a range of software tools has been developed to capture standards-compliant metadata for a variety of data sources. The geoportal is unique in that, in our review of over 120 geoportals worldwide, we have not previously encountered a geoportal dedicated to supporting quantitative and qualitative social science academic and policy research. A particularly innovative aspect of the geoportal has involved the building of a rich meta-database of government surveys, geo-referenced semantically-tagged qualitative data (generated from primary research), ‘grey’ data (e.g. from transcripts, journal publications, books, PhD theses) and Government administrative data. This article describes the challenges faced during the development of the WISERD Geoportal which can be accessed via http://www.wiserd.ac.uk/geoportal/. Numéro de notice : A2012-155 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2012.01308.x Date de publication en ligne : 13/04/2012 En ligne : https://doi.org/10.1111/j.1467-9671.2012.01308.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31602
in Transactions in GIS > vol 16 n° 2 (April 2012) . - pp 105 - 124[article]The use of LiDAR in digital surface modelling: issues and errors / C. Leigh in Transactions in GIS, vol 13 n° 4 (August 2009)
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Titre : The use of LiDAR in digital surface modelling: issues and errors Type de document : Article/Communication Auteurs : C. Leigh, Auteur ; D. Kidner, Auteur ; M.C. Thomas, Auteur Année de publication : 2009 Article en page(s) : pp 345 - 361 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] analyse de données
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] erreur géométrique
[Termes IGN] littoral
[Termes IGN] modèle numérique de surface
[Termes IGN] modèle numérique de terrain
[Termes IGN] Pays de GallesRésumé : (Auteur) Modelling and extracting 3D geographical data presents numerous challenges that require continual research to attempt to evolve an efficient, reliable and accurate solution. LiDAR data capture and analysis has become a preferred acquisition choice for elevation data because the resulting quality and level of detail far exceeds traditional methods for large survey areas. As with any data collection system, LiDAR is prone to errors. Analysing these errors, ascertaining causes and producing error correction strategies is vital if accurate and confident results are to be obtained. Eight years of LiDAR datasets (from 1998 to 2005) have been closely analysed for a large coastal area of South Wales. This article provides a detailed and accurate summary of the identified LiDAR data issues and subsequent errors which affect the accuracy of end products such as Digital Surface Models (DSMs). Copyright Blackwell Publishing Numéro de notice : A2009-527 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/j.1467-9671.2009.01168.x En ligne : https://doi.org/10.1111/j.1467-9671.2009.01168.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30156
in Transactions in GIS > vol 13 n° 4 (August 2009) . - pp 345 - 361[article]Rule-based classification of multi-temporal satellite imagery for habitat and agricultural land cover mapping / Robert Lucas in ISPRS Journal of photogrammetry and remote sensing, vol 62 n° 3 (August 2007)
PermalinkAn examination of GIS success within local government departments in the U.K. and in Trinidad and Tobago / S.M. Baban in Surveying and land information science, vol 66 n° 4 (01/12/2006)
PermalinkEuropean property information, EULIS: removing barriers to cross-border lending / J. Atkey in GIM international, vol 20 n° 7 (July 2006)
PermalinkMapping urban extent using satellite radar interferometry / W. Grey in Photogrammetric Engineering & Remote Sensing, PERS, vol 69 n° 9 (September 2003)
PermalinkEffects of topography on radiance from upland vegetation in north Wales / A.G. Thomson in International Journal of Remote Sensing IJRS, vol 11 n° 5 (May 1990)
PermalinkPopulation densities of sheep related to Landsat Thematic Mapper radiance / A.G. Thomson in International Journal of Remote Sensing IJRS, vol 10 n° 12 (December 1989)
PermalinkUse of digital terrain data in the interpretation of Spot-1 HRV multispectral imagery / A. Jones in International Journal of Remote Sensing IJRS, vol 9 n° 4 (April 1988)
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