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Improved salient feature-based approach for automatically separating photosynthetic and nonphotosynthetic components within terrestrial Lidar point cloud data of forest canopies / Lixia Ma in IEEE Transactions on geoscience and remote sensing, vol 54 n° 2 (February 2016)
[article]
Titre : Improved salient feature-based approach for automatically separating photosynthetic and nonphotosynthetic components within terrestrial Lidar point cloud data of forest canopies Type de document : Article/Communication Auteurs : Lixia Ma, Auteur ; Guang Zheng, Auteur ; Jan U.H. Eitel, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 679 - 696 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] analyse en composantes indépendantes
[Termes IGN] canopée
[Termes IGN] classification automatique
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] feuillu
[Termes IGN] Leaf Area Index
[Termes IGN] photosynthèse
[Termes IGN] Pinophyta
[Termes IGN] reconnaissance de formes
[Termes IGN] semis de points
[Termes IGN] télémétrie laser sur satellite
[Termes IGN] zone saillante 3DRésumé : (Auteur) Accurate separation of photosynthetic and nonphotosynthetic components in a forest canopy from 3-D terrestrial laser scanning (TLS) data is a challenging but of key importance to understand the spatial distribution of the radiation regime, photosynthetic processes, and carbon and water exchanges of the forest canopy. The objective of this paper was to improve current methods for separating photosynthetic and nonphotosynthetic components in TLS data of forest canopies by adding two additional filters only based on its geometric information. By comparing the proposed approach with the eigenvalues plus color information-based method, we found that the proposed approach could effectively improve the overall producer's accuracy from 62.12% to 95.45%, and the overall classification producer's accuracy would increase from 84.28% to 97.80% as the forest leaf area index (LAI) decreases from 4.15 to 3.13. In addition, variations in tree species had negligible effects on the final classification accuracy, as shown by the overall producer's accuracy for coniferous (93.09%) and broadleaf (94.96%) trees. To remove quantitatively the effects of the woody materials in a forest canopy for improving TLS-based LAI estimates, we also computed the “woody-to-total area ratio” based on the classified linear class points from an individual tree. Automatic classification of the forest point cloud data set will facilitate the application of TLS on retrieving 3-D forest canopy structural parameters, including LAI and leaf and woody area ratios. Numéro de notice : A2016-114 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2015.2459716 En ligne : https://doi.org/10.1109/TGRS.2015.2459716 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79992
in IEEE Transactions on geoscience and remote sensing > vol 54 n° 2 (February 2016) . - pp 679 - 696[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2016021 SL Revue Centre de documentation Revues en salle Disponible Is waveform worth it? A comparison of LiDAR approaches for vegetation and landscape characterization / Karen Anderson in Remote sensing in ecology and conservation, vol 2 n° 1 (February 2016)
[article]
Titre : Is waveform worth it? A comparison of LiDAR approaches for vegetation and landscape characterization Type de document : Article/Communication Auteurs : Karen Anderson, Auteur ; Steven Hancock, Auteur ; Mathias I. Disney, Auteur ; Kevin J. Gaston, Auteur Année de publication : 2016 Article en page(s) : pp 5 - 15 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] canopée
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] forêt
[Termes IGN] forme d'onde
[Termes IGN] sous-bois
[Termes IGN] sous-étageRésumé : (auteur) Light Detection and Ranging (LiDAR) systems are frequently used in ecological studies to measure vegetation canopy structure. Waveform LiDAR systems offer new capabilities for vegetation modelling by measuring the time-varying signal of the laser pulse as it illuminates different elements of the canopy, providing an opportunity to describe the 3D structure of vegetation canopies more fully. This article provides a comparison between waveform airborne laser scanning (ALS) data and discrete return ALS data, using terrestrial laser scanning (TLS) data as an independent validation. With reference to two urban landscape typologies, we demonstrate that discrete return ALS data provided more biased and less consistent measurements of woodland canopy height (in a 100% tree covered plot, height underestimation bias = 0.82 m; SD = 1.78 m) than waveform ALS data (height overestimation bias = 0.65 m; SD = 1.45 m). The same biases were found in suburban data (in a plot consisting of 100% hard targets e.g. roads and pavements), but discrete return ALS were more consistent here than waveform data (SD=0.57 m compared to waveform SD=0.76 m). Discrete return ALS data performed poorly in describing the canopy understorey, compared to waveform data. Our results also highlighted errors in discrete return ALS intensity, which were not present with waveform data. Waveform ALS data therefore offer an improved method for measuring the three-dimensional structure of vegetation systems, but carry a higher data processing cost. New toolkits for analysing waveform data will expedite future analysis and allow ecologists to exploit the information content of waveform LiDAR. Numéro de notice : A2016--166 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.1002/rse2.8 En ligne : http://doi.org/10.1002/rse2.8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=87172
in Remote sensing in ecology and conservation > vol 2 n° 1 (February 2016) . - pp 5 - 15[article]Mangrove forest characterization in Southeast Côte d’Ivoire / Isimemen Osemwegie in Open journal of forestry, vol 6 n° 3 (February 2016)
[article]
Titre : Mangrove forest characterization in Southeast Côte d’Ivoire Type de document : Article/Communication Auteurs : Isimemen Osemwegie, Auteur ; Dibi N'da Hyppolite, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 138 - 150 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse diachronique
[Termes IGN] biomasse aérienne
[Termes IGN] biomasse forestière
[Termes IGN] caractérisation
[Termes IGN] changement climatique
[Termes IGN] Côte d'Ivoire
[Termes IGN] Leaf Area Index
[Termes IGN] mangrove
[Termes IGN] palétuvier
[Termes IGN] peuplement forestier
[Termes IGN] puits de carbone
[Termes IGN] structure d'un peuplement forestier
[Termes IGN] teneur en carbone
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Mangrove ecosystems are faced with far more existential threats of erosion than their terrestrial counterparts. Consequences of their degradation vary from decline in edible aquatic stocks, coastal erosion and aquatic weeds invasion. Mangrove forest dynamics was assessed from multi-temporal analyses of remotely sensed satellite images (mosaics of 1989/90 and 2014/15) within 233,900 hectares. Ground-truthing was accompanied by field measurements in selected forest stands to characterize structure, estimate biomass and carbon pools. With conservation as overriding goal, a socio-economic survey was conducted to underpin the factors influencing mangrove forests over-exploitation and qualitatively assess the sensitivity of the locals to resources decline. The region recorded fifty percent loss of mangrove area during the 25-year period. Low leaf area index (1.02 - 2.52 m2·m-2) confirms canopy openness. Above-ground root biomass (kg per root) ranged between 110.67 and 382.64. The roots demonstrate capacity to fix up to 176 Mg C ha-1 with average carbon content of 46 percent. Highest carbon pools were in the Eloka-To forest stands, in near natural conditions. Despite harsh environmental conditions, potential for natural regeneration was evidenced by seedlings density (individuals per m2) up to 76. Pilot survey revealed high dependence on mangrove resources for direct income (70 percent) and daily energy needs (60 percent). Despite the heightened awareness of the impending dangers posed by mangrove deforestation and willingness to conserve, riverine communities are incapacitated by lack of viable economic alternatives. External interventions are therefore imperative to achieve conservation goals with long-term implications for climate change adaptation and mitigation. Numéro de notice : A2016-147 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.4236/oje.2016.63014 En ligne : http://dx.doi.org/ 10.4236/oje.2016.63014 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80346
in Open journal of forestry > vol 6 n° 3 (February 2016) . - pp 138 - 150[article]Optimising the spatial resolution of WorldView-2 pan-sharpened imagery for predicting levels of Gonipterus scutellatus defoliation in KwaZulu-Natal, South Africa / Romano Lottering in ISPRS Journal of photogrammetry and remote sensing, vol 112 (February 2016)
[article]
Titre : Optimising the spatial resolution of WorldView-2 pan-sharpened imagery for predicting levels of Gonipterus scutellatus defoliation in KwaZulu-Natal, South Africa Type de document : Article/Communication Auteurs : Romano Lottering, Auteur ; Onisimo Mutanga, Auteur Année de publication : 2016 Article en page(s) : pp 13–22 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] Afrique du sud (état)
[Termes IGN] Eucalyptus (genre)
[Termes IGN] image Worldview
[Termes IGN] indice de végétation
[Termes IGN] insecte phyllophage
[Termes IGN] optimisation (mathématiques)
[Termes IGN] pouvoir de résolution spectrale
[Termes IGN] prévention des risquesRésumé : (auteur) Gonipterus scutellatus Gyllenhal is a leaf feeding weevil that is a major defoliator of the genus Eucalyptus. Understanding the relationship between levels of weevil induced vegetation defoliation and the optimal spatial resolution of satellite images is essential for effective management of plantation resources. The objective of this study was to identify appropriate spatial resolutions for predicting levels of weevil induced defoliation. We resampled the Normalized Difference Vegetation Index (NDVI), Simple Ratio (SR) and Enhanced Vegetation Index (EVI) images computed from a WorldView-2 pan-sharpened image, which is characterised with a 0.5 m spatial resolution and 8 spectral bands. Within each plantation compartment 30 × 30 m plots were established, representing different levels of defoliation. From the centre of each plot, the spatial resolution of the original image was progressively resampled from 1.5 to 8.5 m, with 1 m increments. The minimal variance for each level of defoliation was then established and used as an indicator for quantitatively selecting the optimal spatial resolution. Results indicate that an appropriate spatial resolution was established at 1.25, 1.25, 1.75 and 2.25 m for low, medium, high and severe levels of defoliation, respectively. In addition, an Artificial Neural Network was run to determine the relationship between the appropriate spatial resolution and levels of Gonipterus scutellatus induced defoliation. The model yielded an R2 of 0.80, with an RMSE of 1.28 (2.45% of the mean measured defoliation) based on an independent test dataset. We then compared this model to a model developed using the original 0.5 m image spatial resolution. Our results suggest that optimising the spatial resolution of remotely sensed imagery essentially improves the prediction of vegetation defoliation. In essence, this study provides the foundation for multi-scale defoliation mapping using high spatial resolution imagery. Numéro de notice : A2016-136 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2015.11.010 En ligne : https://doi.org/10.1016/j.isprsjprs.2015.11.010 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80307
in ISPRS Journal of photogrammetry and remote sensing > vol 112 (February 2016) . - pp 13–22[article]Statistical rigor in LiDAR-assisted estimation of aboveground forest biomass / Timothy G. Gregoire in Remote sensing of environment, vol 173 (February 2016)
[article]
Titre : Statistical rigor in LiDAR-assisted estimation of aboveground forest biomass Type de document : Article/Communication Auteurs : Timothy G. Gregoire, Auteur ; Erik Naesset, Auteur ; Ronald E. McRoberts, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 98 - 108 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] biomasse aérienne
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] échantillonnage
[Termes IGN] incertitude géométrique
[Termes IGN] inférence statistique
[Termes IGN] varianceRésumé : (auteur) For many decades remotely sensed data have been used as a source of auxiliary information when conducting regional or national surveys of forest resources. In the past decade, airborne scanning LiDAR (Light Detection and Ranging) has emerged as a promising tool for sample surveys aimed at improving estimation of above-ground forest biomass. This technology is now employed routinely in forest management inventories of some Nordic countries, and there is eager anticipation for its application to assess changes in standing biomass in vast tropical regions of the globe in concert with the UN REDD program to limit C emissions. In the rapidly expanding literature on LiDAR-assisted biomass estimation the assessment of the uncertainty of estimation varies widely, ranging from statistically rigorous to ad hoc. In many instances, too, there appears to be no recognition of different bases of statistical inference which bear importantly on uncertainty estimation. Statistically rigorous assessment of uncertainty for four large LiDAR-assisted surveys is expounded. Numéro de notice : A2016--160 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2015.11. En ligne : https://doi.org/10.1016/j.rse.2015.11.012 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=87012
in Remote sensing of environment > vol 173 (February 2016) . - pp 98 - 108[article]Terrestrial laser scanning in forest inventories / Xinlian Liang in GIM international [en ligne], vol 30 n° 2 (February 2016)PermalinkUse of GIS-supported comparative cartography and historical maps in long-term forest cover changes analysis in the Holy cross mountains (Poland) / Tadeusz Ciupa in Baltic forestry, vol 22 n° 1 ([01/02/2016])PermalinkValidation of medium-scale historical maps of southern Latvia for evaluation of impact of continuous forest cover on the present-day mean stand area and tree species richness / Anda Fescenko in Baltic forestry, vol 22 n° 1 ([01/02/2016])PermalinkAbove-ground and below-ground competition between the willow Salix caprea and its understorey / Ondřej Mudrák in Journal of vegetation science, vol 27 n° 1 (January 2016)PermalinkAn interactive system for intrinsic validation of citizen science data for species distribution mapping and modelling applications / Hossein Vahidi (2016)PermalinkApplication of topo-edaphic factors and remotely sensed vegetation indices to enhance biomass estimation in a heterogeneous landscape in the Eastern Arc mountains of Tanzania / Mercy Ojoyi in Geocarto international, vol 31 n° 1 - 2 (January - February 2016)PermalinkApplication des techniques de photogrammétrie par drone à la caractérisation des ressources forestières / Jonathan Lisein (2016)PermalinkApport de la télédétection radar satellitaire pour la cartographie de la forêt des Landes / Yousra Hamrouni (2016)PermalinkAssessment of forest canopy vertical structure with multi - scale remote sensing : from the plot to the large area / Phil Wilkes (2016)PermalinkPermalink