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Resource-based growth models reveal opportunities to mitigate climate change effects on beech regeneration by silvicultural measures / Jan F. Wilkens in Forest ecology and management, vol 532 (March-15 2023)
[article]
Titre : Resource-based growth models reveal opportunities to mitigate climate change effects on beech regeneration by silvicultural measures Type de document : Article/Communication Auteurs : Jan F. Wilkens, Auteur ; Robert Schlicht, Auteur ; Sven Wagner, Auteur Année de publication : 2023 Article en page(s) : n° 120815 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Europe (géographie politique)
[Termes IGN] Fagus sylvatica
[Termes IGN] gestion forestière
[Termes IGN] modèle de croissance végétale
[Termes IGN] rayonnement solaire
[Termes IGN] régénération (sylviculture)
[Termes IGN] semis (sylviculture)
[Termes IGN] sylviculture
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Successful European beech (Fagus sylvatica L.) regeneration is both of great ecological and economical importance in European forest ecosystems and severely threatened by climate change impacts. To increase our knowledge of beech regeneration dynamics under climate change and the potential for controlling it through forest management, we studied interactive effects of solar radiation (PHAR), water and nutrient availability on the height growth of artificially (AR) and naturally regenerated (NR) beech seedlings. The study was conducted in the framework of experimental canopy gaps, under the influence of the 2018/19 drought and heatwaves. We measured PHAR by means of hemispherical photography, approximated water availability based on the inverse of modeled fine root density distributions of overstorey beech (BGRB) and oak (BGRO) and approximated nutrient availability based on soil fertility (SF), derived from forest site mapping. Results indicate that seedling resource availability and resulting growth responses increase with canopy gap size and vary among locations within the gap. Multiplicative non-linear mixed models suggest that AR and NR relative height growth (RI) was best explained by interactive effects of PHAR, BGRB, BGRO and SF, which reflect complementary resource use patterns of beech seedlings. At optimal resource availability, AR reached a potential RI of 174%, which is about 20% higher compared to NR. While the low light growth responses of AR and NR both reflect saturation at 5 to 15% PHAR, depending on individual size and the availability of the remaining resources, NR showed a higher RI than AR at intermediate and high PHAR levels in cases of limited BGR and SF. In contrast to AR, NR growth was affected to a lesser extent by SF and BGRB and not significantly affected by BGRO. These results suggest that overstorey oaks have a lower effect on water availability of beech seedlings than overstorey beeches. Additionally, NR showed higher tolerance to water and nutrient limitation than AR, probably due to better root system development. In conclusion, site-specific potential for mitigating the effects of climate change on beech regeneration through forest management lies in the adaptation of silvicultural systems, i.e., the creation of canopy gaps larger than 200 m2, thus significantly exceeding the average gap size of the natural disturbance regime, and the choice of the regeneration method. Numéro de notice : A2023-164 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2023.120815 Date de publication en ligne : 26/01/2023 En ligne : https://doi.org/10.1016/j.foreco.2023.120815 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102869
in Forest ecology and management > vol 532 (March-15 2023) . - n° 120815[article]Evaluation of strategies for the ultra-rapid orbit prediction of BDS GEO satellites / Wenxi Zhao in Geo-spatial Information Science, vol 26 n° 1 (March 2023)
[article]
Titre : Evaluation of strategies for the ultra-rapid orbit prediction of BDS GEO satellites Type de document : Article/Communication Auteurs : Wenxi Zhao, Auteur ; Xiaolei Dai, Auteur ; Yidong Lou, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : pp 16 - 30 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales
[Termes IGN] constellation BeiDou
[Termes IGN] éclipse solaire
[Termes IGN] orbite géostationnaire
[Termes IGN] orbitographie
[Termes IGN] rayonnement solaireRésumé : (auteur) The quality of BeiDou Navigation Satellite System (BDS) Geostationary Earth Orbit (GEO) ultra-rapid products is unsatisfactory because GEO satellites are nearly stationary relative to ground stations. To optimize the quality of these ultra-rapid orbit products, we investigated the effects of the fitting arc length, an a priori Solar-Radiation Pressure (SRP) model, and the along-track empirical acceleration on the prediction of BDS GEO satellite orbits. The predicted orbit arcs of 24-h were evaluated through comparisons with the corresponding observed orbit arc and Satellite Laser Ranging (SLR) observations. In both eclipse and non-eclipse seasons, accuracy of the orbit predictions obtained using a 48-h fitting arc length were better than those obtained using 24-h and 72-h fitting arc lengths. Although the overlapping precision of predicted orbits exhibited no obvious improvement when an a priori SRP model was employed, the systematic bias in the SLR residuals was significantly reduced. Specifically, the mean value of SLR residuals decreased from −0.248 m to −0.024 m during non-eclipse seasons and from −0.333 m to −0.041 m during eclipse seasons, respectively. In addition, when an empirical acceleration in the along-track direction was introduced, the three-Dimensional Root-Mean-Square (3D RMS) of overlapping orbits during eclipse seasons decreased from 2.964 to 1.080 m, which is comparable to that during non-eclipse seasons. Furthermore, the Standard Deviation (STD) of SLR residuals decreased from 0.419 to 0.221 m during eclipse seasons. The analysis of SRP estimates shows that the stability of SRP parameters was significantly enhanced after the introduction of along-track empirical acceleration in eclipse seasons. The optimal BDS GEO ultra-rapid orbit prediction products were yielded by using a 48-h fitting arc length, an a priori SRP model and an along-track empirical acceleration. Numéro de notice : A2023-182 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/10095020.2022.2071177 En ligne : https://doi.org/10.1080/10095020.2022.2071177 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102968
in Geo-spatial Information Science > vol 26 n° 1 (March 2023) . - pp 16 - 30[article]BDS-3 precise orbit and clock solution at Wuhan University: status and improvement / Jing Guo in Journal of geodesy, vol 97 n° 2 (February 2023)
[article]
Titre : BDS-3 precise orbit and clock solution at Wuhan University: status and improvement Type de document : Article/Communication Auteurs : Jing Guo, Auteur ; Guo Chen, Auteur ; Xiaolong Xu, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : n° 15 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales
[Termes IGN] horloge du satellite
[Termes IGN] orbite précise
[Termes IGN] orbitographie
[Termes IGN] positionnement par BeiDou
[Termes IGN] rayonnement solaire
[Termes IGN] signal BeiDouRésumé : (auteur) With the rapid deployment of the third-generation satellites of the BeiDou Navigation Satellite System (BDS-3), Wuhan University (WHU) has incorporated BDS-3 satellites to its routine Multi-GNSS analysis since Day of Year 1, 2019. This article summarizes the processing strategy and presents the validation results of the WHU BDS-3 orbit and clock solutions submitted to the International GNSS Service Multi-GNSS Experiment in 2019. Although more than 200 stations with B1I and B3I signals tracking capability can be used for BDS-3 precise orbit determination, the number of tracking stations for different satellites diverges greatly; in general, more stations track those launched early and less those deployed late. The validations with orbit boundary misclosures, orbit differences with respect to BDS-3 products of GeoForschungsZentrum (GFZ) and Satellite Laser Ranging (SLR) residuals show that the orbits are affected by the number of tracking stations and the deficiency of dynamic models. To overcome the latter, an a priori solar radiation pressure (SRP) model has been proposed considering the Earth albedo and antenna thrust. The SLR validation shows that the new SRP model significantly improves the orbit from 5 to 7 cm to about 3 to 4 cm by reducing the Sun-elongation-angle-dependent errors of the BDS-3 orbits. Besides, the clock products have been compared with those of GFZ, and the root-mean-square (RMS) of clock linear fit is also analyzed. Noticeable different quality has been shown for Rubidium Atomic Frequency Standard and Passive Hydrogen Maser (PHM) clocks. The Sun-elevation-angle-dependent patterns are identified in PHM clocks, and the RMS of clock linear fit of PHM clocks can be reduced with improved dynamic modeling, particularly in eclipse seasons. Numéro de notice : A2023-131 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-023-01705-5 En ligne : https://doi.org/10.1007/s00190-023-01705-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102674
in Journal of geodesy > vol 97 n° 2 (February 2023) . - n° 15[article]Spatiotemporal accuracy evaluation and errors analysis of global VTEC maps using a simulation technique / Jian Lin in GPS solutions, vol 27 n° 1 (January 2023)
[article]
Titre : Spatiotemporal accuracy evaluation and errors analysis of global VTEC maps using a simulation technique Type de document : Article/Communication Auteurs : Jian Lin, Auteur ; Xinxing Li, Auteur ; Shenfeng Gu, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : n° 6 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] données GPS
[Termes IGN] harmonique sphérique
[Termes IGN] modèle cartographique
[Termes IGN] modèle ionosphérique
[Termes IGN] phase
[Termes IGN] rayonnement solaire
[Termes IGN] simulation
[Termes IGN] station GPS
[Termes IGN] teneur verticale totale en électronsRésumé : (auteur) The computation of vertical total electron content (VTEC) maps has become an important issue gradually for the international GNSS service. Given the current literature reports, little research is involved in the quantitative analysis of each error of the VTEC map and the spatiotemporal characteristic of global VTEC accuracy. Based on the single layer model and sphere harmonic function, we propose an approach using simulated GPS data to comprehensively verify the accuracy of the VTEC map. The spatiotemporal characteristic of global VTEC accuracy and the errors induced by different processing steps, i.e., carrier phase to code leveling, mapping function (MF), DCB estimation and coefficient fitting, are analyzed and discussed in detail. In addition, the effect of solar activity on the accuracy of the global VTEC map, MF and DCB estimation has been discussed. The results suggest: First, it is found that the MF error at sunrise is more significant than that at sunset, and this important characteristic can be proven based on the analysis of theory and ionospheric radio occultation and VTEC measurements; second, the MF is the most significant error source in the VTEC processing for regions with dense and homogeneous distributed GPS stations, e.g., North America and Europe. The VTEC accuracy in these regions can be improved by 100% with the satellite elevation cutoff angle increasing from 12° to 30°; finally, compared with the global VTEC accuracy using 350 GPS stations observations, the accuracy is improved by 306% based on the double GPS stations with even distribution. Numéro de notice : A2023-002 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-022-01343-y Date de publication en ligne : 13/10/2022 En ligne : https://doi.org/10.1007/s10291-022-01343-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101871
in GPS solutions > vol 27 n° 1 (January 2023) . - n° 6[article]MLMT-CNN for object detection and segmentation in multi-layer and multi-spectral images / Majedaldein Almahasneh in Machine Vision and Applications, vol 33 n° 1 (January 2022)
[article]
Titre : MLMT-CNN for object detection and segmentation in multi-layer and multi-spectral images Type de document : Article/Communication Auteurs : Majedaldein Almahasneh, Auteur ; Adeline Paiement, Auteur ; Xianghua Xie, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 9 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] apprentissage dirigé
[Termes IGN] apprentissage profond
[Termes IGN] atmosphère solaire
[Termes IGN] classification par réseau neuronal convolutif
[Termes IGN] couche thématique
[Termes IGN] détection d'objet
[Termes IGN] image multibande
[Termes IGN] segmentation d'imageRésumé : (auteur) Precisely localising solar Active Regions (AR) from multi-spectral images is a challenging but important task in understanding solar activity and its influence on space weather. A main challenge comes from each modality capturing a different location of the 3D objects, as opposed to typical multi-spectral imaging scenarios where all image bands observe the same scene. Thus, we refer to this special multi-spectral scenario as multi-layer. We present a multi-task deep learning framework that exploits the dependencies between image bands to produce 3D AR localisation (segmentation and detection) where different image bands (and physical locations) have their own set of results. Furthermore, to address the difficulty of producing dense AR annotations for training supervised machine learning (ML) algorithms, we adapt a training strategy based on weak labels (i.e. bounding boxes) in a recursive manner. We compare our detection and segmentation stages against baseline approaches for solar image analysis (multi-channel coronal hole detection, SPOCA for ARs) and state-of-the-art deep learning methods (Faster RCNN, U-Net). Additionally, both detection and segmentation stages are quantitatively validated on artificially created data of similar spatial configurations made from annotated multi-modal magnetic resonance images. Our framework achieves an average of 0.72 IoU (segmentation) and 0.90 F1 score (detection) across all modalities, comparing to the best performing baseline methods with scores of 0.53 and 0.58, respectively, on the artificial dataset, and 0.84 F1 score in the AR detection task comparing to baseline of 0.82 F1 score. Our segmentation results are qualitatively validated by an expert on real ARs. Numéro de notice : A2022-089 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1007/s00138-021-01261-y Date de publication en ligne : 29/11/2021 En ligne : https://doi.org/10.1007/s00138-021-01261-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99500
in Machine Vision and Applications > vol 33 n° 1 (January 2022) . - n° 9[article]Automatic atmospheric correction for shortwave hyperspectral remote sensing data using a time-dependent deep neural network / Jian Sun in ISPRS Journal of photogrammetry and remote sensing, vol 174 (April 2021)PermalinkPermalinkGalileo and QZSS precise orbit and clock determination using new satellite metadata / Xingxing Li in Journal of geodesy, vol 93 n° 8 (August 2019)PermalinkSeasonal pattern in time series of variances of GPS residual errors Anova estimates / Darko Anđić in Geodetski vestnik, vol 63 n° 2 (June - August 2019)PermalinkTemporal and spatial high-resolution climate data from 1961 to 2100 for the German National Forest Inventory (NFI) / Helge Dietrich in Annals of Forest Science, vol 76 n° 1 (March 2019)PermalinkSimultaneous characterization of objects temperature and radiative properties through multispectral infrared thermography / Thibaud Toullier (2019)PermalinkA method of downscaling temperature maps based on analytical hillshading for use in species distribution modelling / Ángel M. Felicísimo in Cartography and Geographic Information Science, Vol 45 n° 4 (July 2018)PermalinkUse of LiDAR for calculating solar irradiance on roofs and façades of buildings at city scale: Methodology, validation, and analysis / Liang Cheng in ISPRS Journal of photogrammetry and remote sensing, vol 138 (April 2018)PermalinkFactors affecting forest dynamics in the Iberian Peninsula from 1987 to 2012 : The role of topography and drought / Juan José Vidal-Macua in Forest ecology and management, vol 406 (15 December 2017)PermalinkIonospheric error contribution to GNSS single-frequency navigation at the 2014 solar maximum / Raul Orus Perez in Journal of geodesy, vol 91 n° 4 (April 2017)PermalinkEstimating the solar transmittance of urban trees using airborne LiDAR and radiative transfer simulation / Haruki Oshio in IEEE Transactions on geoscience and remote sensing, vol 54 n° 9 (September 2016)PermalinkEstimation of satellite antenna phase center offsets for Galileo / Peter Steigenberger in Journal of geodesy, vol 90 n° 8 (August 2016)PermalinkThin cloud removal based on signal transmission principles and spectral mixture analysis / Meng Xu in IEEE Transactions on geoscience and remote sensing, vol 54 n° 3 (March 2016)PermalinkTrouver le Nord / Olivier Le Carrer (2016)PermalinkEffet de l’exposition sur la richesse et la composition floristique des lisières forestières dans le Gâtinais oriental (Loiret) / Richard Chevalier in Revue forestière française, vol 67 n° 5 (septembre 2015)PermalinkCODE’s new solar radiation pressure model for GNSS orbit determination / Daniel Arnold in Journal of geodesy, vol 89 n° 8 (August 2015)PermalinkEnhanced solar radiation pressure modeling for Galileo satellites / Oliver Montenbruck in Journal of geodesy, vol 89 n° 3 (March 2015)PermalinkReducing the draconitic errors in GNSS geodetic products / C.J. Rodriguez-Solano in Journal of geodesy, vol 88 n° 6 (June 2014)PermalinkAtmospheric water vapour sensing by means of differential absorption spectrometry using solar and lunar radiation / Stefan Walter Münch (2014)PermalinkJournées 2013, Systèmes de référence spatio-temporels, Paris, 16 - 18 September 2013 / Nicole Capitaine (2014)PermalinkObserver la Terre depuis l'espace / Cathy Dubois (2014)PermalinkLe système de DORIS et certaines améliorations récentes / Jordane Strittmatter in XYZ, n° 136 (septembre - novembre 2013)PermalinkPermalinkMaterial reflectance retrieval in urban tree shadows with physics-based empirical atmospheric correction / Karine R.M. Adeline (2013)PermalinkA new 3-D solar radiation model for 3-D city models / Jaroslav Hofierka in Transactions in GIS, vol 16 n° 5 (October 2012)PermalinkTopographic corrections of satellite data for regional monitoring / S. Goslee in Photogrammetric Engineering & Remote Sensing, PERS, vol 78 n° 9 (September 2012)PermalinkUsing GRASS GIS to model solar irradiation on North Carolina aquatic habitats with canopy data / D. Newcomb in Transactions in GIS, vol 16 n° 2 (April 2012)PermalinkCartes, boussoles et GPS / Jean-Marc Lord (2012)PermalinkInterference & Einstein: GNSS update / Huibert-Jan Lekkerkerk in Geoinformatics, vol 15 n° 1 (01/01/2012)PermalinkLa modélisation 3D : une nouvelle voie pour les documents d'urbanisme : Application à l'optimisation énergétique des bâtiments / Aurélie Prévost in Revue internationale de géomatique, vol 21 n° 4 (décembre 2011 – février 2012)PermalinkValidation of international reference ionosphere models using in situ measurements from GRACE K-band ranging system and CHAMP planar Langmuir probe / C. Lee in Journal of geodesy, vol 85 n° 12 (December 2011)PermalinkHigh-precision GNSS receivers / N. Blanco-Delgado in GIM international, vol 25 n° 11 (November 2011)PermalinkAccuracy assessment of the GPS-TEC calibration constants by means of a simulation technique / Jacques Conte in Journal of geodesy, vol 85 n° 10 (October 2011)PermalinkAn evaluation of solar radiation pressure strategies for the GPS constellation / Ant Sibthorpe in Journal of geodesy, vol 85 n° 8 (August 2011)PermalinkImpact de la modélisation de la force de pression de radiation solaire sur les séries temporelles de mouvements du géocentre déterminées par traitement des données DORIS / Marie-Line Gobinddass in Bulletin d'information scientifique et technique de l'IGN, n° 77 (avril 2011)PermalinkGNSS and the Ionosphere: What's in Store for the Next Solar Maximum? / A. Jensen in GPS world, vol 22 n° 2 (February 2011)PermalinkAnnuaire du Bureau des longitudes, Guide de données astronomiques 2012 pour l'observation du ciel / Bureau des longitudes (2011)PermalinkAnnuaire du Bureau des longitudes, Guide de données astronomiques 2011 pour l'observation du ciel / Bureau des longitudes (2010)PermalinkEtude des erreurs systématiques liées à la détermination du géocentre par les mesures DORIS / Marie-Line Gobinddass (2010)PermalinkSystematic biases in DORIS-derived geocenter time series related to solar radiation pressure mis-modeling / Marie-Line Gobinddass in Journal of geodesy, vol 83 n° 9 (September 2009)PermalinkA comparative analysis of DEM-based models to estimate the solar radiation in mountainous terrain / J. Ruiz-Arias in International journal of geographical information science IJGIS, vol 23 n° 7-8 (july 2009)PermalinkAnnuaire du Bureau des Longitudes, Guide de données astronomiques 2010, pour l'observation du ciel / Bureau des longitudes (2009)PermalinkL'astronomie au service de tous / J.E. Arlot (2009)PermalinkSystème solaire et planètes / Anny-Chantal Levasseur-Regourd (2009)PermalinkAnnuaire du Bureau des Longitudes, Guide de données astronomiques 2009, pour l'observation du ciel / Bureau des longitudes (2008)Permalink