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Light mode and dark mode: Which one is suitable when using public-facing web maps? An experimental evaluation using eye-tracking / Lige Qiao in Transactions in GIS, vol 27 n° 2 (april 2023)  

Public [article]  inTransactions in GIS > vol 27 n° 2 (april 2023) . - pp 516 - 540 Titre : Light mode and dark mode: Which one is suitable when using public-facing web maps? An experimental evaluation using eye-tracking Type de document : Article/Communication Auteurs : Lige Qiao, Auteur ; Mingguang Wu, Auteur Année de publication : 2023 Article en page(s) : pp 516 - 540 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] cognition [Termes IGN] Google Maps [Termes IGN] intensité lumineuse [Termes IGN] lecture de carte [Termes IGN] lisibilité optique [Termes IGN] oculométrie [Termes IGN] rayonnement lumineux [Termes IGN] visualisation cartographique [Termes IGN] web mapping [Vedettes matières IGN] Cartologie Résumé : (auteur) Dark maps, which are also called dark modes or dark themes, have gained popularity, but their usability has not been experimentally evaluated. This article presents a user experiment that uses eye-tracking to assess the usability of dark and light maps. Here, two widely used web maps, Google Maps and Gaode Maps, are selected at the street and city scales. Eight map-use tasks are designed and cover four operations (identify, compare, rank, and associate) with space-alone and attributes-in-space distinctions. Four pairs of map-use tasks (light-during-the-day, dark-during-the-day, dark-at-night, and light-at-night) are examined from three aspects: effectiveness, efficiency, and cognitive load. The results provide preliminary evidence that the light-during-the-day performance is generally the best in most cases, followed by the dark-at-night performance; the dark-during-the-day performance is the worst in all cases, followed by the light-at-night performance, which suggests that aligning the map design with the environment (i.e., lighting environment) is critical for better communication. The light-during-the-day performance is the best for space-alone tasks, and the dark-at-night performance is the best for attributes-in-space tasks. Our investigation also indicates that dark maps are far less favored in practice, which suggests that users' preference for using the dark mode of public-facing web maps needs to be shaped. Since light and dark maps are associated with photopic and scotopic vision, respectively, the results indicate the need for future studies on how to leverage scotopic vision to design better dark maps. Numéro de notice : A2023-196 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1111/tgis.13038 Date de publication en ligne : 19/03/2023 En ligne : https://doi.org/10.1111/tgis.13038 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=103081 [article]

Regeneration in European beech forests after drought: the effects of microclimate, deadwood and browsing / Dominik Thom in European Journal of Forest Research, vol 142 n° 2 (April 2023)  

Public [article]  inEuropean Journal of Forest Research > vol 142 n° 2 (April 2023) . - pp 259 - 27 Titre : Regeneration in European beech forests after drought: the effects of microclimate, deadwood and browsing Type de document : Article/Communication Auteurs : Dominik Thom, Auteur ; Christian Ammer, Auteur ; Peter Annighöfer, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : pp 259 - 27 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Allemagne [Termes IGN] bois mort [Termes IGN] Fagus sylvatica [Termes IGN] rayonnement lumineux [Termes IGN] régénération (sylviculture) [Termes IGN] sécheresse [Termes IGN] sous-étage [Termes IGN] température de l'air [Vedettes matières IGN] Végétation et changement climatique Résumé : (auteur) With progressing climate change, increasing weather extremes will endanger tree regeneration. Canopy openings provide light for tree establishment, but also reduce the microclimatic buffering effect of forests. Thus, disturbances can have both positive and negative impacts on tree regeneration. In 2015, three years before an extreme drought episode hit Central Europe, we established a manipulation experiment with a factorial block design in European beech (Fagus sylvatica L.)-dominated forests. At five sites located in southeastern Germany, we conducted three censuses of tree regeneration after implementing two different canopy disturbances (aggregated and distributed canopy openings), and four deadwood treatments (retaining downed, standing, downed + standing deadwood and removing all deadwood), as well as in one untreated control plot. In addition, we measured understory light levels and recorded local air temperature and humidity over five years. We (i) tested the effects of experimental disturbance and deadwood treatments on regeneration and (ii) identified the drivers of regeneration density as well as seedling species and structural diversity. Regeneration density increased over time. Aggregated canopy openings supported species and structural diversity, but reduced regeneration density. Tree regeneration was positively associated with understory light levels, while maximum vapor pressure deficit influenced tree regeneration negatively. Deadwood and browsing impacts on regeneration varied and were inconclusive. Our study indicates that despite the drought episode regeneration in beech-dominated forests persisted under moderately disturbed canopies. However, the positive effect of increased light availability on tree regeneration might have been offset by harsher microclimate after canopies have been disturbed. Numéro de notice : A2023-197 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1007/s10342-022-01520-1 Date de publication en ligne : 24/11/2022 En ligne : https://doi.org/10.1007/s10342-022-01520-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=103084 [article]

Multi-sensor airborne lidar requires intercalibration for consistent estimation of light attenuation and plant area density / Grégoire Vincent in Remote sensing of environment, vol 286 (March 2023)  

Public [article]  inRemote sensing of environment > vol 286 (March 2023) . - n° 113442 Titre : Multi-sensor airborne lidar requires intercalibration for consistent estimation of light attenuation and plant area density Type de document : Article/Communication Auteurs : Grégoire Vincent, Auteur ; Philippe Verley, Auteur ; Benjamin Brede, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : n° 113442 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] canopée [Termes IGN] densité de la végétation [Termes IGN] données lidar [Termes IGN] forêt tropicale [Termes IGN] Guyane (département français) [Termes IGN] image captée par drone [Termes IGN] plan de vol [Termes IGN] rayonnement lumineux [Termes IGN] réflectance végétale [Termes IGN] semis de points [Termes IGN] zone d'intérêt Résumé : (auteur) Leaf area is a key structural characteristic of forest canopies because of the role of leaves in controlling many biological and physical processes occurring at the biosphere-atmosphere transition. High pulse density Airborne Laser Scanning (ALS) holds promise to provide spatially resolved and accurate estimates of plant area density (PAD) in forested landscapes, a key step in understanding forest functioning: phenology, carbon uptake, transpiration, radiative balance etc. Inconsistencies between different ALS sensors is a barrier to generating globally harmonised PAD estimates. The basic assumption on which PAD estimation is based is that light attenuation is proportional to vegetation area density. This study shows that the recorded extinction strongly depends on target detectability which is influenced by laser characteristics (power, sensitivity, wavelength). Three different airborne laser scanners were flown over a wet tropical forest at the Paracou research station in French Guiana. Different sensors, flight heights and transmitted power levels were compared. Light attenuation was retrieved with an open source ray-tracing code (http://amapvox.org). Direct comparison revealed marked differences (up-to 25% difference in profile-averaged light attenuation rate and 50% difference at particular heights) that could only be explained by differences in scanner characteristics. We show how bias which may occur under various acquisition conditions can generally be mitigated by a sensor intercalibration. Alignment of light weight lidar attenuation profiles to ALS reference attenuation profiles is not always satisfactory and we discuss what are the likely sources of discrepancies. Neglecting the dependency of apparent light attenuation on scanner properties may lead to biases in estimated vegetation density commensurate to those affecting light attenuation estimates. Applying intercalibration procedures supports estimation of plant area density independent of acquisition characteristics. Numéro de notice : A2023-169 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.1016/j.rse.2022.113442 Date de publication en ligne : 06/01/2023 En ligne : https://doi.org/10.1016/j.rse.2022.113442 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102928 [article]

Caractériser l’environnement compétitif des arbres : dépassons la surface terrière ! / Thomas Cordonnier in Revue forestière française, vol 73 n° 6 (2021)  

Public [article]  inRevue forestière française > vol 73 n° 6 (2021) . - pp 643 - 648 Titre : Caractériser l’environnement compétitif des arbres : dépassons la surface terrière ! Type de document : Article/Communication Auteurs : Thomas Cordonnier, Auteur Année de publication : 2022 Article en page(s) : pp 643 - 648 Note générale : bibliographie Langues : Français (fre) Descripteur : [Termes IGN] houppier [Termes IGN] rayonnement lumineux [Termes IGN] surface terrière [Vedettes matières IGN] Inventaire forestier Résumé : (auteur) Dans le domaine forestier, la surface terrière est couramment utilisée pour caractériser la compétition entre les arbres d’un peuplement. Pourtant, les développements théoriques des deux dernières décennies permettent de conclure que cette approche est insuffisante, notamment vis-à-vis de la compétition pour la ressource lumière. La théorie nous indique même que la bonne performance, dans certains cas, de la surface terrière ne serait que fortuite et liée à des conditions bien spécifiques. C’est ce que nous présentons et discutons dans cette courte note. Nous appelons ainsi la communauté forestière française à développer et valoriser davantage les mesures des houppiers afin de mieux rendre compte de la compétition entre arbres au sein des peuplements forestiers. Numéro de notice : A2022-790 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.20870/revforfr.2021.7202 Date de publication en ligne : 27/10/2022 En ligne : https://doi.org/10.20870/revforfr.2021.7202 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102998 [article]

Exploiting light directionality for image-based 3D reconstruction of non-collaborative surfaces / Ali Karami in Photogrammetric record, vol 37 n° 177 (March 2022)  

Public [article]  inPhotogrammetric record > vol 37 n° 177 (March 2022) . - pp 111 - 138 Titre : Exploiting light directionality for image-based 3D reconstruction of non-collaborative surfaces Type de document : Article/Communication Auteurs : Ali Karami, Auteur ; Fabio Menna, Auteur ; Fabio Remondino, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : pp 111 - 138 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique [Termes IGN] appariement d'images [Termes IGN] axe de prise de vue [Termes IGN] étalonnage [Termes IGN] figure géométrique [Termes IGN] point d'appui [Termes IGN] points homologues [Termes IGN] rayonnement lumineux [Termes IGN] reconstruction 3D [Termes IGN] reconstruction d'objet [Termes IGN] semis de points Résumé : (auteur) Three-dimensional (3D) measurement of non-collaborative surfaces is still an open research topic. This paper investigates and quantifies for the first time the effect of light directionality and fusion of multiple images as a method to improve the quality of photogrammetric 3D reconstruction. For this aim, an image acquisition system that employs multiple light sources was developed to highlight the roughness and microstructures of the object under investigation. Images were captured at various grazing angles to highlight the local surface roughness and microstructures. Individual point clouds, created using images taken at different grazing angles, were produced using dense image-matching techniques. These point clouds were then compared against different 3D photogrammetric reconstructions obtained from a pre-processing of the acquired images based on diffuse lighting, median and average images. Experiments showed that exploiting light directionality significantly improves image-matching quality. Furthermore, depending on the light direction, the root mean square (RMS) error of the 3D surfaces obtained using the proposed system were up to 50% less than those created by traditional diffuse lighting. Numéro de notice : A2022-208 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/phor.12400 Date de publication en ligne : 07/03/2022 En ligne : https://doi.org/10.1111/phor.12400 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100218 [article]

Diffuse sunlight and cosmic rays: Missing pieces of the forest growth change attribution puzzle? / Jean-Daniel Bontemps in Science of the total environment, vol 806 n°1 (February 2022)  

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Atmospheric correction to passive microwave brightness temperature in snow cover mapping over china / Yubao Qiu in IEEE Transactions on geoscience and remote sensing, vol 59 n° 8 (August 2021)  

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Extraction of urban built-up areas from nighttime lights using artificial neural network / Tingting Xu in Geocarto international, vol 35 n° 10 ([01/08/2020])  

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Improved depth estimation for occlusion scenes using a light-field camera / Changkun Yang in Photogrammetric Engineering & Remote Sensing, PERS, vol 86 n° 7 (July 2020)  

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10th Colour and Visual Computing Symposium 2020 (CVCS 2020), Gjøvik, Norway, and Virtual, September 16-17, 2020 / Jean-Baptiste Thomas (2020)  

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Caractérisation du manteau neigeux arctique, suivi climatique et télédétection micro-onde / Céline Vargel (2020)  

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Improved algorithms for the measurement of total precipitable water and cloud liquid water from SARAL microwave radiometer observations / Rajput Neha Mangalsinh in Marine geodesy, vol 42 n° 4 (July 2019)  

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Evaluating metrics derived from Landsat 8 OLI imagery to map crop cover / Rei Sonobe in Geocarto international, vol 34 n° 8 ([15/06/2019])  

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Improving the spatial bias correction algorithm in SMOS image reconstruction processor : validation of soil moisture retrievals with in situ data / Ali Khazaal in IEEE Transactions on geoscience and remote sensing, vol 57 n° 1 (January 2019)  

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Machine learning for image segmentation / Kaiwen Chang (2019)  

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