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Ground-penetrating radar measurement of crop and surface water content dynamics / G. Serbin in Remote sensing of environment, vol 96 n° 1 (15/05/2005)
[article]
Titre : Ground-penetrating radar measurement of crop and surface water content dynamics Type de document : Article/Communication Auteurs : G. Serbin, Auteur ; D. Or, Auteur Année de publication : 2005 Article en page(s) : pp 119 - 134 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] diffusion du rayonnement
[Termes IGN] humidité du sol
[Termes IGN] masse végétale
[Termes IGN] propriété diélectrique
[Termes IGN] radar pénétrant GPR
[Termes IGN] réflectance de surface
[Termes IGN] réflectance du sol
[Termes IGN] sous-bois
[Termes IGN] temps de propagation
[Termes IGN] teneur en eau de la végétationRésumé : (Auteur) Ground-penetrating radar (GPR) with a suspended 1 GHz horn antenna was deployed for measurement of soil water contents and crop canopy properties over bare and electrically terminating surfaces. Surface reflection (SR) and signal propagation times (PT) were used to independently determine dielectric permittivity and water content of soil and canopy. Measured surface reflection coefficients progressively decreased with increasing canopy biomass according to Beer-Lambert type relationships. In contrast, PT measurements remained unaffected by canopy, and hence provided an accurate account of soil water content dynamics. Immediately after canopy removal, SR-based soil water content measurements were in close agreement with PT values. Canopy dielectric properties were inferred from canopy water contents (ec-CWC) and canopy propagation times (ec-CPT). Distinct canopy reflections were correlated with key canopy biophysical parameters. The study demonstrates the usefulness of a horn antenna GPR for characterization of vegetation canopy scattering, and for subcanopy water content measurements within a well-defined footprint, thereby offering a potential for calibration and verification of radar data collected from air- and spacebome platforms. Numéro de notice : A2005-212 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2005.01.018 En ligne : https://doi.org/10.1016/j.rse.2005.01.018 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27349
in Remote sensing of environment > vol 96 n° 1 (15/05/2005) . - pp 119 - 134[article]Small-footprint lidar estimation of sub-canopy elevation and tree height in a tropical rain forest landscape / M.L. Clarke in Remote sensing of environment, vol 91 n° 1 (15/05/2004)
[article]
Titre : Small-footprint lidar estimation of sub-canopy elevation and tree height in a tropical rain forest landscape Type de document : Article/Communication Auteurs : M.L. Clarke, Auteur ; D. Clark, Auteur ; D.A. Roberts, Auteur Année de publication : 2004 Article en page(s) : pp 68 - 89 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] corrélation linéaire
[Termes IGN] données lidar
[Termes IGN] erreur moyenne quadratique
[Termes IGN] forêt tropicale
[Termes IGN] interpolation inversement proportionnelle à la distance
[Termes IGN] modèle numérique de surface
[Termes IGN] modèle numérique de terrain
[Termes IGN] sous-bois
[Termes IGN] télémétrie laser aéroportéRésumé : (Auteur) Meso-scale digital terrain models (DTMs) and canopy-height estimates, or digital canopy models (DCMs), are two lidar products that have immense potential for research in tropical rain forest (TRF) ecology and management. In this study, we used a small-footprint lidar sensor (airborne laser scanner, ALS) to estimate sub-canopy elevation and canopy height in an evergreen tropical rain forest. A fully automated, local-minima algorithm was developed to separate lidar ground returns from overlying vegetation returns. We then assessed inverse distance weighted (IDW) and ordinary kriging (OK) geostatistical techniques for the interpolation of a sub-canopy DTM. OK was determined to be a superior interpolation scheme because it smoothed fine-scale variance created by spurious understory heights in the ground-point dataset. The final DTM had a linear correlation of 1.00 and a root-mean-square error (RMSE) of 2.29 m when compared against 3859 well-distributed ground-survey points. In old-growth forests, RMS error on steep slopes was 0.67 m greater than on flat slopes. On flatter slopes, variation in vegetation complexity associated with land use caused highly significant differences in DTM error distribution across the landscape. The highest DTM accuracy observed in this study was 0.58-m RMSE, under flat, open-canopy areas with relatively smooth surfaces. Lidar ground retrieval was complicated by dense, multi-layered evergreen canopy in old-growth forests, causing DTM overestimation that increased RMS error to 1.95 m.
A DCM was calculated from the original lidar surface and the interpolated DTM. Individual and plot-scale heights were estimated from DCM metrics and compared to field data measured using similar spatial supports and metrics. For old-growth forest emergent trees and isolated pasture trees greater than 20 in tall, individual tree heights were underestimated and had 3.67- and 2.33-m mean absolute error (MAE), respectively. Linear-regression models explained 51% (4.15-m RMSE) and 95% (2.41-m RMSE) of the variance, respectively. It was determined that improved elevation and field-height estimation in pastures explained why individual pasture trees could be estimated more accurately than old-growth trees. Mean height of tree stems in 32 young agroforestry plantation plots (0.38 to 18.53 m tall) was estimated with a mean absolute error of 0.90 m (r 2 = 0,97; 1.08-m model RMSE) using the mean of lidar returns in the plot. As in other small-footprint lidar studies, plot mean height was underestimated; however, our plot-scale results have stronger linear models for tropical, leaf-on hardwood trees than has been previously reported for temperate-zone conifer and deciduous hardwoods.Numéro de notice : A2004-237 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2004.02.008 En ligne : https://doi.org/10.1016/j.rse.2004.02.008 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26764
in Remote sensing of environment > vol 91 n° 1 (15/05/2004) . - pp 68 - 89[article]Remote sensing of temperate coniferous forest leaf area index : the influence of canopy closure, understory vegetation and background reflectance / M.A. Spanner in International Journal of Remote Sensing IJRS, vol 11 n° 1 (January 1990)
[article]
Titre : Remote sensing of temperate coniferous forest leaf area index : the influence of canopy closure, understory vegetation and background reflectance Type de document : Article/Communication Auteurs : M.A. Spanner, Auteur ; L.L. Pierce, Auteur ; David L. Peterson, Auteur ; S.W. Running, Auteur Année de publication : 1990 Article en page(s) : pp 95 - 111 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] correction géométrique
[Termes IGN] couvert forestier
[Termes IGN] forêt tempérée
[Termes IGN] Green Leaf Area Index
[Termes IGN] image Landsat-TM
[Termes IGN] Oregon (Etats-Unis)
[Termes IGN] Pinophyta
[Termes IGN] réflectance végétale
[Termes IGN] sous-boisNuméro de notice : A1990-024 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431169008955002 En ligne : https://doi.org/10.1080/01431169008955002 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=25448
in International Journal of Remote Sensing IJRS > vol 11 n° 1 (January 1990) . - pp 95 - 111[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 080-90011 RAB Revue Centre de documentation En réserve L003 Disponible Thematic Mapper detection of changes in the leaf area of closed canopy pine plantations in central Massachusetts / S.R. Herwitz in Remote sensing of environment, vol 30 n° 2 (November 1989)
[article]
Titre : Thematic Mapper detection of changes in the leaf area of closed canopy pine plantations in central Massachusetts Type de document : Article/Communication Auteurs : S.R. Herwitz, Auteur ; David L. Peterson, Auteur ; J. Ronald Eastman, Auteur Année de publication : 1989 Article en page(s) : pp 129 - 140 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] aiguille
[Termes IGN] détection de changement
[Termes IGN] image Landsat-TM
[Termes IGN] indice de végétation
[Termes IGN] Massachusetts (Etats-Unis)
[Termes IGN] Pinus (genre)
[Termes IGN] réflectance végétale
[Termes IGN] sous-bois
[Termes IGN] sylvicultureNuméro de notice : A1989-075 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/0034-4257(89)90055-2 En ligne : https://doi.org/10.1016/0034-4257(89)90055-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=25035
in Remote sensing of environment > vol 30 n° 2 (November 1989) . - pp 129 - 140[article]Reflectance from shrubs and under-shrub soil in a semiarid environment / H.D. Williamson in Remote sensing of environment, vol 29 n° 3 (01/09/1989)
[article]
Titre : Reflectance from shrubs and under-shrub soil in a semiarid environment Type de document : Article/Communication Auteurs : H.D. Williamson, Auteur Année de publication : 1989 Article en page(s) : pp 263 - 271 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] Australie
[Termes IGN] bande infrarouge
[Termes IGN] flore locale
[Termes IGN] image Landsat-MSS
[Termes IGN] indice de végétation
[Termes IGN] réflectance du sol
[Termes IGN] sous-bois
[Termes IGN] zone semi-arideNuméro de notice : A1989-443 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/0034-4257(89)90005-9 En ligne : https://doi.org/10.1016/0034-4257(89)90005-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=25401
in Remote sensing of environment > vol 29 n° 3 (01/09/1989) . - pp 263 - 271[article]