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Termes IGN > sciences naturelles > sciences de la vie > biologie > botanique > formation végétale > forêt > canopée
canopée
Commentaire :
interface forêt-atmosphère. forêt, association végétale. >> écologie de la canopée. Source(s) : Glossaire d'écologie fondamentale / M. Duquet, 1993. Equiv. LCSH : Forest canopies. Domaine(s) : 580. Synonyme(s)Voûte forestièreVoir aussi |
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Initial analysis and visualization of waveform laser scanner data / Johanna Töpel (2005)
Titre : Initial analysis and visualization of waveform laser scanner data Type de document : Mémoire Auteurs : Johanna Töpel, Auteur Editeur : Linköping [Suède] : Linköping Institute of Technology Année de publication : 2005 Importance : 63 p. Format : 21 x 30 cm Note générale : bibliographie
Master’s Thesis in Automatic ControlLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] algorithme espérance-maximisation
[Termes IGN] canopée
[Termes IGN] classification orientée objet
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] faisceau laser
[Termes IGN] forêt
[Termes IGN] forme d'onde
[Termes IGN] forme d'onde pleine
[Termes IGN] impulsion laser
[Termes IGN] semis de points
[Termes IGN] signal laser
[Termes IGN] visualisation 3DRésumé : (auteur) Conventional airborne laser scanner systems output the three-dimensional coordinates of the surface location hit by the laser pulse. Data storage capacity and processing speeds available today has made it possible to digitally sample and store the entire reflected waveform, instead of only extracting the coordinates. Research has shown that return waveforms can give even more detailed insights into the vertical structure of surface objects, surface slope, roughness and reflectivity than the conventional systems. One of the most important advantages with registering the waveforms is that it gives the user the possibility to himself define the way range is calculated in post-processing. In this thesis different techniques have been tested to visualize a waveform data set in order to get a better understanding of the waveforms and how they can be used to improve methods for classification of ground objects. A pulse detection algorithm, using the EM algorithm, has been implemented and tested. The algorithm output position and width of the echo pulses. One of the results of this thesis is that echo pulses reflected by vegetation tend to be wider than those reflected by for example a road. Another result is that up till five echo pulses can be detected compared to two echo pulses that the conventional system detects. Note de contenu : Introduction
1- Registred waveform
2- Lidar data
3- Documentation of waveforms
4- Vizualisation
5- Pulse detection
6- Extracted points
7- DiscussionNuméro de notice : 21710 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Mémoire masters divers Organisme de stage : Swedish Defence Research Agency FOI Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90997 Leaf Area Index measurements in a tropical moist forest: a case study from Costa Rica / M. Kalacska in Remote sensing of environment, vol 91 n° 2 (30/05/2004)
[article]
Titre : Leaf Area Index measurements in a tropical moist forest: a case study from Costa Rica Type de document : Article/Communication Auteurs : M. Kalacska, Auteur ; G.A. Sanchez-Azofeifa, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 134 - 152 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] canopée
[Termes IGN] Costa Rica
[Termes IGN] forêt tropicale
[Termes IGN] indice de végétation
[Termes IGN] Leaf Area Index
[Termes IGN] méthode des moindres carrés
[Termes IGN] régression linéaireRésumé : (Auteur) The role of tropical forests in sustainable development mechanisms and payments for environmental services is becoming increasingly important. Therefore, there is a greater need for accurate and detailed information about their biophysical characteristics (e.g., Leaf area index-LAI) along different stages of ecological succession. Remote sensing offers the possibility of providing relatively accurate estimations of such biophysical characteristics at a reasonable cost for most regional projects. The objectives of this study are to (1) document the variability of LAI in different stages of secondary growth in a tropical moist forest, (2) estimate LAI from spectral vegetation indices (SVIs), and (3) link LAI to the estimation of other canopy physiognomic characteristics. We found that segregation of LAI measurements by successional stage (early, intermediate, late) contributed to a better definition of the relationship between LAI and the SVIs. In addition, we conclude that the propagation of errors of precision through the SVI formulas must be taken into consideration along with intra-site and radiometric variability when uncertainty terms are calculated. From a linear regression analysis, we found that there is only a minimal difference between the nonparametric Theil-Sen and classical least-squares regressions. We also found that not only does the Lorentzian cumulative transition function describe the relationship between LAI and the SVIs, it also provides an estimate of the range of LAI values to which each index is sensitive. Numéro de notice : A2004-241 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2004.02.011 En ligne : https://doi.org/10.1016/j.rse.2004.02.011 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26768
in Remote sensing of environment > vol 91 n° 2 (30/05/2004) . - pp 134 - 152[article]Estimating fragmentation effects on simulated forest net primary productivity derived from satellite imagery / Nicholas C. Coops in International Journal of Remote Sensing IJRS, vol 25 n° 4 (February 2004)
[article]
Titre : Estimating fragmentation effects on simulated forest net primary productivity derived from satellite imagery Type de document : Article/Communication Auteurs : Nicholas C. Coops, Auteur ; J.D. White, Auteur ; N.A. Scott, Auteur Année de publication : 2004 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] canopée
[Termes IGN] carbone
[Termes IGN] écosystème forestier
[Termes IGN] forêt
[Termes IGN] image multibande
[Termes IGN] image SPOT-Végétation
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] Nouvelle-Zélande
[Termes IGN] production primaire netteRésumé : (Auteur) Conversion of native forests to agriculture and urban land leads to fragmentation of forested landscapes with significant consequences for habitat conservation and forest productivity. When quantifying land-cover patterns from airborne or spaceborne sensors, the interconnectedness of fragmented landscapes may vary depending on the spatial resolution of the sensor and the extent at which the landscape is being observed. This scale dependence can significantly affect calculation of remote sensing vegetation indices, such as the Normalized Difference Vegetation Index (NDVI) and its subsequent use to predict biophysical parameters such as the fraction of photosynthetically active radiation intercepted by forest canopies (fPAR). This means that simulated above-ground net primary productivity (NPPA) using canopy radiation interception models such as 3-PG (Physiological Principles for Predicting Growth), coupled with remote sensing observations, can yield different results in fragmented landscapes depending on the spatial resolution of the remotely sensed data. We compared the amount of forest fragmentation in 1 km SPOT-4 VEGETATION pixels using a simultaneously acquired 20m SPOT-4 multispectral (XS) image. We then predicted NPPA for New Zealand native forest ecosystems using the 3-PG model with satellite-derived estimates of the WAR obtained from the SPOT-4 VEGETATION sensor, using NDVI values with and without correction for fragmentation. We examined three methods to correct for sub-pixel fragmentation effects on NPPA. These included: (1) a simple conversion between the broad 1 km scale NDVI values and the XS NDVI values; (2) utilisation of contextural information from XS NDVI pixels to derive a single coefficient to adjust the 1 km NDVI values; and (3) calculation of the degree of fragmentation within each VEGETATION 1 km pixel and reduce NDVI by an empirically derived amount based on the proportional areal coverage of forest in each pixel. Our results indicate that predicted NPPA derived from uncorrected 1 km VEGETATION pixels was significantly higher than estimates using adjusted NDVI values; all three methods reduced the predicted NPPA. In areas of the landscape with a large degree of forest defragmentation (such as forest boundaries) predictions of NPPa indicate that the fragmentation effect has implications for spatially extensive estimates of carbon uptake by forests. Numéro de notice : A2004-076 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/0143116031000115094 En ligne : https://doi.org/10.1080/0143116031000115094 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26604
in International Journal of Remote Sensing IJRS > vol 25 n° 4 (February 2004)[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-04041 RAB Revue Centre de documentation En réserve L003 Exclu du prêt Improving tropical forest mapping using multi-date Landsat TM data and pre-classification image smoothing / C. Tottrup in International Journal of Remote Sensing IJRS, vol 25 n° 4 (February 2004)
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Titre : Improving tropical forest mapping using multi-date Landsat TM data and pre-classification image smoothing Type de document : Article/Communication Auteurs : C. Tottrup, Auteur Année de publication : 2004 Article en page(s) : pp 717 - 730 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse diachronique
[Termes IGN] canopée
[Termes IGN] carte de la végétation
[Termes IGN] classification par maximum de vraisemblance
[Termes IGN] écosystème
[Termes IGN] forêt tropicale
[Termes IGN] image Landsat-TM
[Termes IGN] image multitemporelle
[Termes IGN] lissage de donnéesRésumé : (Auteur) The present study explores the possibility of using Landsat imagery for mapping tropical forest types with relevance to forest ecosystem services. The central part in the classification process is the use of multi-date image data and pre-classification image smoothing. The study argues that multi-date imagery contains information on phenological and canopy structural properties and shows how the use of multi-date imagery has a significant impact on classification accuracy. Furthermore, the study shows the value of applying small kernel smoothing filters to reduce in-class spectral variability and enhance between-class spectral separability. Making use of these approaches and a maximum likehood algorithm, six tropical forest types were classified with an overall accuracy of 90.94%, and with individual forest classes mapped with accuracies above 75.19% (user's accuracy) and above 74.17% (producer accuracy). Numéro de notice : A2004-074 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160310001598926 En ligne : https://doi.org/10.1080/01431160310001598926 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26602
in International Journal of Remote Sensing IJRS > vol 25 n° 4 (February 2004) . - pp 717 - 730[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-04041 RAB Revue Centre de documentation En réserve L003 Exclu du prêt Prospects for quantifying structure, floristic composition and species richness of tropical forests / T.W. Gillespie in International Journal of Remote Sensing IJRS, vol 25 n° 4 (February 2004)
[article]
Titre : Prospects for quantifying structure, floristic composition and species richness of tropical forests Type de document : Article/Communication Auteurs : T.W. Gillespie, Auteur ; J.C. Brock, Auteur ; C.W. Wright, Auteur Année de publication : 2004 Article en page(s) : pp 707 - 715 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] biodiversité
[Termes IGN] canopée
[Termes IGN] données lidar
[Termes IGN] espèce végétale
[Termes IGN] flore locale
[Termes IGN] forêt tropicaleRésumé : (Auteur) Airborne spectral and light detection and ranging (lidar) sensors have been used to quantify biophysical cahracteristics of tropical forests. Lidar sensors have provided high-resolution data on forest height, canopy topography, volume and gap size ; and provided estimates on number of strata in a forest, successional status of forests, and above-ground biomass. Spectral sensors have provided data on vegetation types, foliar biochemistry content of forest canopies, tree and canopy phenology, and spectral signatures for selected tree species. A number of advances are theorically possible with individual and combined spectral and lidar sensors for the study of forest structure, floristic composition and species richness. Delineating individual canopies of over-storey trees with small footprint lidar and discrimination of tree architectural types with waveform distributions is possible and would provide scientists with a new method to study tropical forest structure. Combined spectral and lidar data can be used to identify selected tree species and identify the successional status of tropical forest fragments in order to rank forest patches by levels of species richness. It should be possible in the near future to quantify selected patterns of tropical forests at a higher resolution than can currently be undertaken in the field or from space. Numéro de notice : A2004-073 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160310001598917 En ligne : https://doi.org/10.1080/01431160310001598917 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26601
in International Journal of Remote Sensing IJRS > vol 25 n° 4 (February 2004) . - pp 707 - 715[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-04041 RAB Revue Centre de documentation En réserve L003 Exclu du prêt Bidirectional NDVI and atmospherically resistant BRDF inversion for vegetation canopy / F. Gao in IEEE Transactions on geoscience and remote sensing, vol 40 n° 6 (June 2002)PermalinkEstimation of tropical forest canopy temperatures, thermal response numbers, and evapotranspiration using an aircraft-based thermal sensor / J.C. Luvall in Photogrammetric Engineering & Remote Sensing, PERS, vol 56 n° 10 (october 1990)PermalinkA reflectance model for the homogeneous plant canopy and its inversion / T. Nilson in Remote sensing of environment, vol 27 n° 2 (01/02/1989)PermalinkTheory and application of optical remote sensing / G. Asrar (1989)PermalinkCanopy reflectance, photosynthesis, and transpiration : the role of biophysics in the linearity of their interdependence / P.J. Sellers in Remote sensing of environment, vol 21 n° 2 (01/03/1987)PermalinkForest biomass, canopy structure, and species composition relationships with multipolarization L-band Synthetic Aperture Radar data / S.A. Sader in Photogrammetric Engineering & Remote Sensing, PERS, vol 53 n° 2 (february 1987)PermalinkStructure et dynamique de la végétation en milieu tropical semi-aride / V.C. DE Carvalho (1986)PermalinkRéponse spectrale des végétaux / Robert Bariou (1985)PermalinkSignatures spectrales d'objets en télédétection, Colloque International, Avignon (France), 8 - 11 septembre 1981 / Gérard Guyot (1981)Permalink