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3D reconstruction of bridges from airborne laser scanning data and cadastral footprints / Steffen Goebbels in Journal of Geovisualization and Spatial Analysis, vol 5 n° 1 (June 2021)  

Public [article]  inJournal of Geovisualization and Spatial Analysis > vol 5 n° 1 (June 2021) . - n° 10 Titre : 3D reconstruction of bridges from airborne laser scanning data and cadastral footprints Type de document : Article/Communication Auteurs : Steffen Goebbels, Auteur Année de publication : 2021 Article en page(s) : n° 10 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes descripteurs IGN] Allemagne [Termes descripteurs IGN] axe médian [Termes descripteurs IGN] CityGML [Termes descripteurs IGN] données cadastrales [Termes descripteurs IGN] données lidar [Termes descripteurs IGN] empreinte [Termes descripteurs IGN] pont [Termes descripteurs IGN] Ransac (algorithme) [Termes descripteurs IGN] reconstruction 3D [Termes descripteurs IGN] semis de points Résumé : (auteur) The given paper describes a method for automatic 3D reconstruction of bridges from cadastral footprints and airborne laser scanning point clouds. The reconstructed bridges are used to enrich 3D city models. Unlike roofs, decks of bridges are typically smooth without ridge lines or step edges. Therefore, established methods for roof reconstruction are not suitable for bridges. The standard description language for semantic city models is CityGML. This specification of the Open Geospatial Consortium assumes that surfaces are composed of planar polygons. The approximation of smooth decks by planar polygons is achieved by using a medial axis tree. Instead of the medial axis of the footprint, a modified medial axis is computed that does not consider counter bearing edges. The resulting tree represents centerline connections between all counter bearing edges and, in conjunction with filtered height values of a point cloud, serves as the basis for approximation with polygons. In addition to modeling decks, superstructures such as pylons and cables are also derived from the point cloud. For this purpose, planes carrying many superstructure points are detected using the Random Sampling Consensus Algorithm (RANSAC). Images are generated by projecting points onto these planes. Then, image processing methods are used to find connected contours that are extruded to form 3D objects. The presented method was successfully applied to all bridges of two German cities as well as to large bridges built over the Rhine River. Numéro de notice : A2021-359 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1007/s41651-021-00076-9 date de publication en ligne : 12/04/2021 En ligne : https://doi.org/10.1007/s41651-021-00076-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97623 [article]

Development of German-Ukrainian cooperations for education and research in photogrammetry and laser scanning / Thomas Luhmann in Geo-spatial Information Science, vol 24 n° 1 (March 2021)  

Public [article]  inGeo-spatial Information Science > vol 24 n° 1 (March 2021) . - pp 152 - 159 Titre : Development of German-Ukrainian cooperations for education and research in photogrammetry and laser scanning Type de document : Article/Communication Auteurs : Thomas Luhmann, Auteur Année de publication : 2021 Article en page(s) : pp 152 - 159 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Formation [Termes descripteurs IGN] Allemagne [Termes descripteurs IGN] apprentissage en ligne [Termes descripteurs IGN] balayage laser [Termes descripteurs IGN] coopération internationale [Termes descripteurs IGN] enseignement supérieur [Termes descripteurs IGN] formation à distance [Termes descripteurs IGN] modélisation 3D [Termes descripteurs IGN] photogrammétrie [Termes descripteurs IGN] recherche scientifique [Termes descripteurs IGN] traitement de nuage de points [Termes descripteurs IGN] Ukraine Résumé : (Auteur) Since 2011 an intensive international cooperation has been in place between the Institute for Applied Photogrammetry and Geoinformatics (IAPG) at the Jade University of Applied Sciences in Oldenburg, Germany, and various Ukrainian universities. Following an initial contact by Prof. Gottfried Konecny, the first visit was organized, and was followed by many more. In subsequent years an intensive cooperation was established particularly with the National University for Construction and Architecture (KNUCA) in Kiev. In addition to architects and civil engineers, KNUCA also trains geodesists, geo-information scientists and landscape planners. The cooperation today includes the reciprocal exchange of scientists and students, research projects, courses and cooperation at many other levels. In addition, a commercial company has been established, SPM3D LLC, which now employs more than 14 engineers in the field of 3D acquisition, point cloud processing and modeling. This article summarizes the history of the cooperation and presents the results of associated student projects. In addition, results of joint work on the development of a virtual laser scanner are presented, part of a German-Ukrainian initiative to digitize teaching. Numéro de notice : A2021-299 Affiliation des auteurs : non IGN Thématique : IMAGERIE/SOCIETE NUMERIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10095020.2020.1831891 date de publication en ligne : 13/10/2020 En ligne : https://doi.org/10.1080/10095020.2020.1831891 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97384 [article]

European beech leads to more bioactive humus forms but stronger mineral soil acidification as Norway spruce and Scots pine – Results of a repeated site assessment after 63 and 82 years of forest conversion in Central Germany / Florian Achilles in Forest ecology and management, vol 483 ([01/03/2021])  

Public [article]  inForest ecology and management > vol 483 [01/03/2021] . - n° 118769 Titre : European beech leads to more bioactive humus forms but stronger mineral soil acidification as Norway spruce and Scots pine – Results of a repeated site assessment after 63 and 82 years of forest conversion in Central Germany Type de document : Article/Communication Auteurs : Florian Achilles, Auteur ; Alexander Tischer, Auteur ; Markus Bernhardt-Römermann, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 118769 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] Allemagne [Termes descripteurs IGN] analyse diachronique [Termes descripteurs IGN] biomasse forestière [Termes descripteurs IGN] composition d'un peuplement forestier [Termes descripteurs IGN] composition des sols [Termes descripteurs IGN] conversion forestière [Termes descripteurs IGN] Fagus (genre) [Termes descripteurs IGN] gestion forestière [Termes descripteurs IGN] Picea abies [Termes descripteurs IGN] Pinus sylvestris [Termes descripteurs IGN] sol acide [Termes descripteurs IGN] sol forestier [Vedettes matières IGN] Sylviculture Résumé : (auteur) To reduce the effects of extended coniferous monoculture plantations on forest floor and topsoil processes, like amplified acidification or nutrient immobilization in organic layers, small interspersed groups of European beech were planted at the beginning of the 20th century amid large coniferous stands (CS) in Central Germany. Today, these so-called “Green Eyes” (GE) are 82-year old. In our study we focused on two different timelines to investigate the effects of forest conversion on vegetation composition, forest floor and mineral soil properties, encompassing a long-term (>80 year) comparison from tree planting in the 1930s to 2018 and a shorter timeframe nearly spanning 20 years (1999–2018). Since long-term forest conversion experiments (>60 years) across sites sharing a common forest land-use history are scarce, our study allows to contribute to a better evaluation of the long-term effects on changes in soil properties. We linked standard methods assessing soil pH, organic C and total N concentrations as well as stocks as indicators of soil quality changes in forest floor and mineral soil (down to 40 cm depth) to patterns in ground vegetation dynamics (most GE were characterized only by a few herbaceous species). Our results exhibited an effect of forest conversion on the activation in forest floor turnover resulting in increased turnover rates in the GE (GE contain only half of the forest floor OM of CS), hence forming more bioactive humus forms (mull, moder) and a noticeable higher forest floor pH (+0.6 units) compared to CS. The OC translocation from the forest floor into the topsoil is higher under GE (+0.7% OC content), probably building up a stable SOC pool hence contributing to C sequestration. The positive effects of European beech on forest floor quality are related to a stronger acidification of the subsoil during the past 20 years (-0.5 pH units). The base pump effect (uptake of Ca2+, Mg2+, K+ and assimilation into tree biomass in exchange release of H+) in GE led to more acidic conditions (- 0.2 pH units) in the deeper mineral soil compared to CS. This bio-acidification may serve as one reason for subsoil acidification, as observed in our study, pointing out that mineral soil acidification is still an important issue in central European forests. Future restoration of soil base cation pools will still depend on the rate of bio-acidification, on the amount of acidifying air pollutant (and base cation) depositions and on forest management practices (e.g. intensity of biomass removal, soil regeneration-oriented liming). Numéro de notice : A2021-229 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2020.118769 date de publication en ligne : 18/11/2020 En ligne : https://doi.org/10.1016/j.foreco.2020.118769 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97216 [article]

Gridded population mapping for Germany based on building density, height and type from Earth Observation data using census disaggregation and bottom-up estimates / Franz Schug in Plos one, vol 16 n° 3 (March 2021)  

Public [article]  inPlos one > vol 16 n° 3 (March 2021) . - n° 0249044 Titre : Gridded population mapping for Germany based on building density, height and type from Earth Observation data using census disaggregation and bottom-up estimates Type de document : Article/Communication Auteurs : Franz Schug, Auteur ; David Frantz, Auteur ; Sebastian van der Linden, Auteur ; Patrick Hostert, Auteur Année de publication : 2021 Article en page(s) : n° 0249044 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes descripteurs IGN] Allemagne [Termes descripteurs IGN] bati [Termes descripteurs IGN] densité du bâti [Termes descripteurs IGN] estimation statistique [Termes descripteurs IGN] figuration de la densité [Termes descripteurs IGN] image Sentinel-MSI [Termes descripteurs IGN] image Sentinel-SAR [Termes descripteurs IGN] population Résumé : (auteur) Gridded population data is widely used to map fine scale population patterns and dynamics to understand associated human-environmental processes for global change research, disaster risk assessment and other domains. This study mapped gridded population across Germany using weighting layers from building density, building height (both from previous studies) and building type datasets, all created from freely available, temporally and globally consistent Copernicus Sentinel-1 and Sentinel-2 data. We first produced and validated a nation-wide dataset of predominant residential and non-residential building types. We then examined the impact of different weighting layers from density, type and height on top-down dasymetric mapping quality across scales. We finally performed a nation-wide bottom-up population estimate based on the three datasets. We found that integrating building types into dasymetric mapping is helpful at fine scale, as population is not redistributed to non-residential areas. Building density improved the overall quality of population estimates at all scales compared to using a binary building layer. Most importantly, we found that the combined use of density and height, i.e. volume, considerably increased mapping quality in general and with regard to regional discrepancy by largely eliminating systematic underestimation in dense agglomerations and overestimation in rural areas. We also found that building density, type and volume, together with living floor area per capita, are suitable to produce accurate large-area bottom-up population estimates. Numéro de notice : A2021-305 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1371/journal.pone.0249044 date de publication en ligne : 26/03/2021 En ligne : https://doi.org/10.1371/journal.pone.0249044 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97654 [article]

Modelling potential density of natural regeneration of European oak species (Quercus robur L., Quercus petraea (Matt.) Liebl.) depending on the distance to the potential seed source: Methodological approach for modelling dispersal from inventory data at forest enterprise level / Maximilian Axer in Forest ecology and management, vol 482 ([15/02/2021])  

Public [article]  inForest ecology and management > vol 482 [15/02/2021] . - n° 118802 Titre : Modelling potential density of natural regeneration of European oak species (Quercus robur L., Quercus petraea (Matt.) Liebl.) depending on the distance to the potential seed source: Methodological approach for modelling dispersal from inventory data at forest enterprise level Type de document : Article/Communication Auteurs : Maximilian Axer, Auteur ; Robert Schlicht, Auteur ; Sven Wagner, Auteur Année de publication : 2021 Article en page(s) : n° 118802 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] conversion forestière [Termes descripteurs IGN] dispersion [Termes descripteurs IGN] inventaire forestier étranger (données) [Termes descripteurs IGN] pinophyta [Termes descripteurs IGN] planification [Termes descripteurs IGN] Quercus pedunculata [Termes descripteurs IGN] Quercus sessiliflora [Termes descripteurs IGN] régénération (sylviculture) [Termes descripteurs IGN] régression quantile [Termes descripteurs IGN] Saxe (Allemagne) [Termes descripteurs IGN] semis (sylviculture) [Vedettes matières IGN] Sylviculture Résumé : (auteur) The use of natural oak regeneration from admixed oaks and neighbouring oak stands provides an interesting alternative to cost-intensive artificial oak regeneration when aiming for forest conversion of pure coniferous stands. In this study analysis of forest inventory data is done on how far and in what density natural regeneration of both Pedunculate and Sessile oak occurs in coniferous stands. In order to investigate as exclusively as possible the effect of distance to the seed source on the regeneration density of both oaks, the regeneration potential was determined by using quantile regression. By applying a .995th quantile, reducing factors on seedling density, e.g. desiccation, browsing, pathogens or limited resource availability, were excluded as much as possible. Thus, the effect of zoochorus vectors on effective dispersal could be quantified. The regeneration potential was determined based on data from the forest inventory of the Saxony state forest enterprise, Germany, including 2357 sample plots. Remote sensing data, including the location of oaks in the overstorey, were used to determine the distance to the nearest potential seed source. The results of the present study demonstrate that the highest regeneration densities are not found in the immediate vicinity of the nearest seed source, but at distances between 60 and 140 m to it,i.e. the maximum of seedling density per area unit is in some distance to the trees trunk. In the present study, dispersal distances of established regeneration up to 1565 m were detected. From a distance of 1570–2300 m on, there was no oak regeneration. The results prove that acorns are taken from the seed source and that, in addition to barochorus dispersal, the zoochorus dispersal is of great importance for the succession of coniferous stands. The position of potential seed sources is therefore an important information for silvicultural planning, in order to estimate potential oak regeneration densities. Numéro de notice : A2021-228 Affiliation des auteurs : non IGN Nature : Article DOI : 10.1016/j.foreco.2020.118802 date de publication en ligne : 13/12/2020 En ligne : https://doi.org/10.1016/j.foreco.2020.118802 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97208 [article]

Unmixing-based Sentinel-2 downscaling for urban land cover mapping / Fei Xu in ISPRS Journal of photogrammetry and remote sensing, vol 171 (January 2021)  

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Learning from urban form to predict building heights / Nikola Milojevic-Dupont in Plos one, vol 15 n° 12 (December 2020)  

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Mapping forest tree species in high resolution UAV-based RGB-imagery by means of convolutional neural networks / Felix Schiefer in ISPRS Journal of photogrammetry and remote sensing, vol 170 (December 2020)  

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Multistrategy ensemble regression for mapping of built-up density and height with Sentinel-2 data / Christian Geiss in ISPRS Journal of photogrammetry and remote sensing, vol 170 (December 2020)  

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Chloroplast haplotypes of Northern red oak (Quercus rubra L.) stands in Germany suggest their origin from Northeastern Canada / Jeremias Götz in Forests, vol 11 n° 9 (September 2020)  

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Using OpenStreetMap data and machine learning to generate socio-economic indicators / Daniel Feldmeyer in ISPRS International journal of geo-information, vol 9 n° 9 (September 2020)  

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Vehicle detection of multi-source remote sensing data using active fine-tuning network / Xin Wu in ISPRS Journal of photogrammetry and remote sensing, vol 167 (September 2020)  

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Modeling soil erosion after mechanized logging operations on steep terrain in the Northern Black Forest, Germany / Julian Haas in European Journal of Forest Research, vol 139 n°4 (August 2020)  

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Improving precision of field inventory estimation of aboveground biomass through an alternative view on plot biomass / Christoph Kleinn in Forest ecosystems, vol 7 (2020)  

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Genetic variation of introduced red oak (Quercus rubra) stands in Germany compared to North American populations / Tim Pettenkofer in European Journal of Forest Research, vol 139 n° 2 (April 2020)  

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