Descripteur
Documents disponibles dans cette catégorie (260)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
An ecological approach to climate change-informed tree species selection for reforestation / William H. MacKenzie in Forest ecology and management, vol 481 (February 2021)
[article]
Titre : An ecological approach to climate change-informed tree species selection for reforestation Type de document : Article/Communication Auteurs : William H. MacKenzie, Auteur ; Colin R. Mahony, Auteur Année de publication : 2021 Article en page(s) : n° 118705 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] altitude
[Termes IGN] bioclimatologie
[Termes IGN] classification par forêts d'arbres décisionnels
[Termes IGN] Colombie-Britannique (Canada)
[Termes IGN] écosystème forestier
[Termes IGN] facteur édaphique
[Termes IGN] reboisement
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Accounting for climate change in reforestation practices has the potential to be one of the most efficacious adaptation strategies for maintaining future forest ecosystem services. There is a rich literature projecting spatial shifts in climatic suitability for tree species and strong scientific evidence for the necessity of assisted migration. However, there has been limited translation of this research into operational reforestation, due in part to mismatches to the information needs of practitioners. Here, we describe a practitioner-focused climate change informed tree species selection (CCISS) model to support reforestation decisions in British Columbia (BC). CCISS projects the climate change redistribution of bioclimate units from the multi-scaled Biogeoclimatic Ecosystem Classification (BEC) system with machine-learning for 90 modelled futures. It leverages the reforestation knowledge from BEC to make site-specific species projections of reforestation feasibility with climate change uncertainty metrics. We present 21st-century feasibility projections for a comprehensive set of tree species native to western North America. Some general trends are evident: augmentation of the number of feasible species in sub-boreal regions due to the rapid expansion of feasibility for temperate species; attrition at low elevations in southern BC due to declines in the feasibility of native species with little compensation by non-native species; and turnover at mid-elevations as declining feasibility for subalpine species is compensated by uphill expansion of climatic feasibility for submontane species. Edaphic (soil) factors are important; feasibility declines are higher on relatively dry sites than on wetter sites for most species. Our analysis emphasizes that changes in feasibility are species-specific, spatially variable, and influenced by edaphic site factors. By employing the multi-scaled BEC system that currently informs operational reforestation, CCISS facilitates translation of research into actionable guidance for practitioners. Numéro de notice : A2021-226 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2020.118705 Date de publication en ligne : 01/11/2020 En ligne : https://doi.org/10.1016/j.foreco.2020.118705 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97203
in Forest ecology and management > vol 481 (February 2021) . - n° 118705[article]Influence of flight altitude and control points in the georeferencing of images obtained by unmanned aerial vehicle / Lucas Santos Santana in European journal of remote sensing, vol 54 n° 1 (2021)
[article]
Titre : Influence of flight altitude and control points in the georeferencing of images obtained by unmanned aerial vehicle Type de document : Article/Communication Auteurs : Lucas Santos Santana, Auteur ; Gabriel Araújo E Silva Ferraz, Auteur ; Diego Bedin Marin, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 59 - 71 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] altitude
[Termes IGN] capteur aérien
[Termes IGN] géoréférencement
[Termes IGN] hauteur de vol
[Termes IGN] image captée par drone
[Termes IGN] Minas Gerais (Brésil)
[Termes IGN] modèle numérique de terrain
[Termes IGN] photogrammétrie aérienne
[Termes IGN] point d'appui
[Termes IGN] précision géométrique (imagerie)Résumé : (auteur) This study aimed to explore the influence of flight altitude, density, and distribution of ground control points (GCPs) on the digital terrain model (DTM) in surveys conducted by unmanned aerial vehicles (UAVs). A total of 144 photogrammetric projects consisting of 399 aerial photos were carried out in a 2 ha area. These photogrammetric projects involved six GCP distributions (edge, center, diagonal, parallel, stratified, and random), six GCP densities, and four flight altitudes (30, 60, 90, and 120 m). The response surface methodology was used to find interference factors and total root-mean-square error (RMSEt) as well. The 60 m flight altitude presented was the most efficient. Central GCP distribution was observed to have low precision. Using stratified and random edge distributions, 10 GCPs are recommended to achieve geometric precision below 0.07 m at any flight height. However, for studies requiring up to 0.07 m precision, the best distribution was parallel with 4 GCPs at any altitude. Diagonal positioning of the GCPs showed RMSEt values below 0.11 m with 4 GCPs at any altitude. A good distribution of GCPs was found to be important, but the density of GCPs per image was more relevant when obtaining a lower RMSEt. Numéro de notice : A2021-155 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/22797254.2020.1845104 Date de publication en ligne : 10/01/2021 En ligne : https://doi.org/10.1080/22797254.2020.1845104 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97018
in European journal of remote sensing > vol 54 n° 1 (2021) . - pp 59 - 71[article]Elevation models for reproducible evaluation of terrain representation / Patrick Kennelly in Cartography and Geographic Information Science, vol 48 n° 1 (January 2021)
[article]
Titre : Elevation models for reproducible evaluation of terrain representation Type de document : Article/Communication Auteurs : Patrick Kennelly, Auteur ; Tom Patterson, Auteur ; Bernhard Jenny, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 63 - 77 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] altitude
[Termes IGN] données multiéchelles
[Termes IGN] figuré du terrain
[Termes IGN] modèle numérique de surface
[Termes IGN] réalité de terrain
[Termes IGN] relief
[Termes IGN] représentation du relief
[Termes IGN] reproductibilité
[Termes IGN] visualisation de donnéesRésumé : (auteur) This paper proposes elevation models to promote, evaluate, and compare various terrain representation techniques. Our goal is to increase the reproducibility of terrain rendering algorithms and techniques across different scales and landscapes. We introduce elevation models of varying terrain types, available to the user at no cost, with minimal common data imperfections such as missing data values, resampling artifacts, and seams. Three multiscale elevation models are available, each consisting of a set of elevation grids, centered on the same geographic location, with increasing cell sizes and spatial extents. We also propose a collection of single-scale elevation models of archetypal landforms including folded ridges, a braided riverbed, active and stabilized sand dunes, and a volcanic caldera. An inventory of 78 publications with a total of 155 renderings illustrating terrain visualization techniques guided the selection of landform types in the elevation models. The benefits of using the proposed elevation models include straightforward comparison of terrain representation methods across different publications and better documentation of the source data, which increases the reproducibility of terrain representations. Numéro de notice : A2021-715 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/15230406.2020.1830856 Date de publication en ligne : 04/11/2020 En ligne : https://doi.org/10.1080/15230406.2020.1830856 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96459
in Cartography and Geographic Information Science > vol 48 n° 1 (January 2021) . - pp 63 - 77[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 032-2021011 RAB Revue Centre de documentation En réserve L003 Disponible Le parallèle des Pyrénées / Yves Maugard (2021)
Titre : Le parallèle des Pyrénées : Détermination des hauteurs des sommets ; La comparaison du niveau des deux mers 1825 - 1827 Type de document : Monographie Auteurs : Yves Maugard, Auteur Editeur : Auto-Edition Année de publication : 2021 Importance : 107 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-2-9578363-0-7 Note générale : bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Géodésie ancienne
[Termes IGN] altitude
[Termes IGN] dix-neuvième siècle
[Termes IGN] niveau de la mer
[Termes IGN] nivellement
[Termes IGN] parallèle
[Termes IGN] Pyrénées (montagne)
[Termes IGN] triangulationIndex. décimale : 30.01 Géodésie ancienne (postérieure à 1939 et en bon état) Note de contenu : 1- Historique
2- Notions de géodésie et de topographie
3- Opérations géodésiques de 1825 - 1827
4- Nivellement des sites
5- Les calculs
6- Résultats et altitude du Crabère
7- ConclusionNuméro de notice : 28376 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98552 Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 28376-01 30.01 Livre Centre de documentation Géodésie Disponible Error propagation in regional geoid computation using spherical splines, least-squares collocation, and Stokes’s formula / Vegard Ophaug in Journal of geodesy, vol 94 n° 12 (December 2020)
[article]
Titre : Error propagation in regional geoid computation using spherical splines, least-squares collocation, and Stokes’s formula Type de document : Article/Communication Auteurs : Vegard Ophaug, Auteur ; Christian Gerlach, Auteur Année de publication : 2020 Article en page(s) : n° 120 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] altitude
[Termes IGN] collocation par moindres carrés
[Termes IGN] covariance
[Termes IGN] erreur
[Termes IGN] fonction spline
[Termes IGN] formule de Stokes
[Termes IGN] géoïde local
[Termes IGN] propagation d'erreurRésumé : (auteur) Current International Association of Geodesy efforts within regional geoid determination include the comparison of different computation methods in the quest for the “1-cm geoid.” Internal (formal) and external (empirical) approaches to evaluate geoid errors exist, and ideally they should agree. Spherical radial base functions using the spline kernel (SK), least-squares collocation (LSC), and Stokes’s formula are three commonly used methods for regional geoid computation. The three methods have been shown to be theoretically equivalent, as well as to numerically agree on the millimeter level in a closed-loop environment using synthetic noise-free data (Ophaug and Gerlach in J Geod 91:1367–1382, 2017. https://doi.org/10.1007/s00190-017-1030-1PANIST). This companion paper extends the closed-loop method comparison using synthetic data, in that we investigate and compare the formal error propagation using the three methods. We use synthetic uncorrelated and correlated noise regimes, both on the 1-mGal (=10−5 ms−2) level, applied to the input data. The estimated formal errors are validated by comparison with empirical errors, as determined from differences of the noisy geoid solutions to the noise-free solutions. We find that the error propagations of the methods are realistic in both uncorrelated and correlated noise regimes, albeit only when subjected to careful tuning, such as spectral band limitation and signal covariance adaptation. For the SKs, different implementations of the L-curve and generalized cross-validation methods did not provide an optimal regularization parameter. Although the obtained values led to a stabilized numerical system, this was not necessarily equivalent to obtaining the best solution. Using a regularization parameter governed by the agreement between formal and empirical error fields provided a solution of similar quality to the other methods. The errors in the uncorrelated regime are on the level of ∼5 mm and the method agreement within 1 mm, while the errors in the correlated regime are on the level of ∼10 mm, and the method agreement within 5 mm. Stokes’s formula generally gives the smallest error, closely followed by LSC and the SKs. To this effect, we note that error estimates from integration and estimation techniques must be interpreted differently, because the latter also take the signal characteristics into account. The high level of agreement gives us confidence in the applicability and comparability of formal errors resulting from the three methods. Finally, we present the error characteristics of geoid height differences derived from the three methods and discuss them qualitatively in relation to GNSS leveling. If applied to real data, this would permit identification of spatial scales for which height information is preferably derived by spirit leveling or GNSS leveling. Numéro de notice : A2020-784 Affiliation des auteurs : non IGN Thématique : MATHEMATIQUE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-020-01443-y Date de publication en ligne : 27/11/2020 En ligne : https://doi.org/10.1007/s00190-020-01443-y Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96528
in Journal of geodesy > vol 94 n° 12 (December 2020) . - n° 120[article]Local terrain modification method considering physical feature constraints for vector elements / Jiangfeng She in Cartography and Geographic Information Science, Vol 47 n° 5 (September 2020)PermalinkSize dependency of variables influencing fire occurrence in Mediterranean forests of Eastern Spain / Marina Peris-Llopis in European Journal of Forest Research, vol 139 n°4 (August 2020)PermalinkAltimétrie de précision autour du détroit d'Ormuz : détermination d'un géoïde gravimétrique, d'altitudes orthométriques précises et de la variation du niveau moyen de la mer / Jean-Louis Carme in XYZ, n° 163 (juin 2020)Permalink40 ans de géodésie à l'IGN (Institut Géographique National rebaptisé en 2012 Institut national de l'information géographique et forestière) : 2ème partie, la géodésie physique / Françoise Duquenne in XYZ, n° 162 (mars 2020)PermalinkClassifying physiographic regimes on terrain and hydrologic factors for adaptive generalization of stream networks / Lauwrence V. Stanislawski in International journal of cartography, Vol 6 n° 1 (March 2020)PermalinkAssessment of ArcGIS based extraction of geoidal undulation compared to National Geospatial Intelligence Agency (NGA) model – A case study / Sher Muhammad in Journal of applied geodesy, vol 14 n° 1 (January 2020)PermalinkImpact of GPS processing on the estimation of snow water equivalent using refracted GPS signals / Ladina Steiner in IEEE Transactions on geoscience and remote sensing, vol 58 n° 1 (January 2020)PermalinkTransformation 3D des coordonnées GPS en coordonnées Nord Sahara avec la MRE / Medjahed Sid Ahmed in Géomatique expert, n° 130-131 (octobre - décembre 2019)PermalinkIndoor localization for pedestrians with real-time capability using multi-sensor smartphones / Catia Real Ehrlich in Geo-spatial Information Science, vol 22 n° 2 (June 2019)PermalinkApplication de la loi de Benford au contrôle de qualité des modèles numériques de terrain / Laurent Polidori in XYZ, n° 158 (mars 2019)Permalink