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SeaWIFS validation in European coastal waters using optical and bio-geochemical measurements / S.J. Lavender in International Journal of Remote Sensing IJRS, vol 25 n° 7 (April 2004)
[article]
Titre : SeaWIFS validation in European coastal waters using optical and bio-geochemical measurements Type de document : Article/Communication Auteurs : S.J. Lavender, Auteur ; M.H. Pinkerton, Auteur ; J.M. Froidefond, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 1481 - 1488 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] bande visible
[Termes IGN] biologie
[Termes IGN] chlorophylle
[Termes IGN] eaux côtières
[Termes IGN] géochimie
[Termes IGN] image optique
[Termes IGN] image Seawifs
[Termes IGN] océanographie spatialeRésumé : (Auteur) The National Aeronautics & Space Administration (NASA) Sea viewing Wide Field of view Sensor (SeaWiFS) began operational measurement of ocean colour in September 1997. Upgrades to the SeaWiFS data processing system (SeaDAS) have occurred frequently and the effects of these revisions on the remotely sensed estimates of chlorophyll-a concentration (chl-a) have been significant. Measurements of chl-a from research work in the Bay of Biscay and Gulf of Cadiz during 1998-1999 are used to validate the SeaWiFS chl-a product generated using the current version of SeaDAS (version 4.1). The validation data cover coastal and offshore waters, including those dominated by inorganic suspended sediment, and an intense dinoflagellate bloom where shipboard chl-a measurements exceeded 50mgm-3. The standard SeaWiFS chlorophyll algorithm (OC4v4) generally performed well, but significantly over-estimated chl-a where inorganic suspended sediment was present. The algorithm is only applicable to chl-a values up to 64mgm-3, which was less than chl-a at the centre of the bloom. A novel algorithm for chl-a, which first estimates the inherent optical properties of the water, was applied to the SeaWiFS measurements but failed on over 90% of the pixels, perhaps because SeaWiFS is under-estimating water reflectance at the extreme blue end of the visible spectrum. Numéro de notice : A2004-095 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160310001592481 En ligne : https://doi.org/10.1080/01431160310001592481 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26622
in International Journal of Remote Sensing IJRS > vol 25 n° 7 (April 2004) . - pp 1481 - 1488[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-04071 RAB Revue Centre de documentation En réserve L003 Exclu du prêt Hyperspectral vegetation indices and novel algorithms for predicting green LAI of crop canopies: modelling and validation in the context of precision agriculture / D. Haboudane in Remote sensing of environment, vol 90 n° 3 (15/04/2004)
[article]
Titre : Hyperspectral vegetation indices and novel algorithms for predicting green LAI of crop canopies: modelling and validation in the context of precision agriculture Type de document : Article/Communication Auteurs : D. Haboudane, Auteur ; J.R. Miller, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 337 - 352 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] agriculture de précision
[Termes IGN] analyse comparative
[Termes IGN] blé (céréale)
[Termes IGN] chlorophylle
[Termes IGN] cultures
[Termes IGN] données de terrain
[Termes IGN] Glycine max
[Termes IGN] Green Leaf Area Index
[Termes IGN] image CASI
[Termes IGN] image hyperspectrale
[Termes IGN] indice de végétation
[Termes IGN] maïs (céréale)
[Termes IGN] modèle de transfert radiatif
[Termes IGN] prévision
[Termes IGN] réflectance végétaleRésumé : (Auteur) A growing number of studies have focused on evaluating spectral indices in terms of their sensitivity to vegetation biophysical parameters, as well as to external factors affecting canopy reflectance. In this context, leaf and canopy radiative transfer models are valuable for modeling and understanding the behavior of such indices. In the present work, PROSPECT and SAILH models have been used to simulate a wide range of crop canopy reflectances in an attempt to study the sensitivity of a set of vegetation indices to green leaf area index (LAI), and to modify some of them in order to enhance their responsivity to LAI variations. The aim of the paper was to present a method for minimizing the effect of leaf chlorophyll content on the prediction of green LAI, and to develop new algorithms that adequately predict the LAI of crop canopies. Analyses based on both simulated and real hyperspectral data were carried out to compare performances of existing vegetation indices (Normalized Difference Vegetation Index [NDVI], Renormalized Difference Vegetation Index [RDVI], Modified Simple Ratio [MSR], Soil-Adjusted Vegetation Index [SAVI], Soil and Atmospherically Resistant Vegetation Index [SARVI], MSAVI, Triangular Vegetation Index [TVI], and Modified Chlorophyll Absorption Ratio Index [MCARI]) and to design new ones (MTVII, MCARII, MTV12, and MCAR12) that are both less sensitive to chlorophyll content variations and linearly related to green LAI. Thorough analyses showed that the above existing vegetation indices were either sensitive to chlorophyll concentration changes or affected by saturation at high LAI levels. Conversely, two of the spectral indices developed as a part of this study, a modified triangular vegetation index (MTV12) and a modified chlorophyll absorption ratio index (MCAR12), proved to be the best predictors of green LAI. Related predictive algorithms were tested on CASI (Compact Airborne Spectrographic Imager) hyperspectral images and, then, validated using ground truth measurements. The latter were collected simultaneously with image acquisition for different crop types (soybean, corn, and wheat), at different growth stages, and under various fertilization treatments. Prediction power analysis of proposed algorithms based on MCAR12 and MTV12 resulted in agreements between modeled and ground measurement of non-destructive LAI, with coefficients of determination (r) being 0.98 for soybean, 0.89 for com, and 0.74 for wheat. The corresponding RMSE for LAI were estimated at 0.28, 0.46, and 0.85, respectively. Numéro de notice : A2004-201 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2003.12.013 En ligne : https://doi.org/10.1016/j.rse.2003.12.013 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26728
in Remote sensing of environment > vol 90 n° 3 (15/04/2004) . - pp 337 - 352[article]The consequences of urban transformation on net primary productivity in the United States / M.L. Imhoff in Remote sensing of environment, vol 89 n° 4 (29/02/2004)
[article]
Titre : The consequences of urban transformation on net primary productivity in the United States Type de document : Article/Communication Auteurs : M.L. Imhoff, Auteur ; L. Bounoua, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 434 - 443 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] bilan du carbone
[Termes IGN] biogéographie
[Termes IGN] biologie
[Termes IGN] Etats-Unis
[Termes IGN] photosynthèse
[Termes IGN] production agricole
[Termes IGN] urbanisation
[Termes IGN] utilisation du sol
[Termes IGN] variable biophysique (végétation)Résumé : (Auteur) We use data from two satellites and a terrestrial carbon model to quantify the impact of urbanization on the carbon cycle and food production in the US as a result of reduced net primary productivity (NPP). Our results show that urbanization is taking place on the most fertile lands and hence has a disproportionately large overall negative impact on NPP. Urban land transformation in the US has reduced the amount of carbon fixed through photosynthesis by 0.04 pg per year or 1.6% of the pre-urban input. The reduction is enough to offset the 1.8% gain made by the conversion of land to agricultural use, even though urbanization covers an area less than 3% of the land surface in the US and agricultural lands approach 29% of the total land area. At local and regional scales, urbanization increases NPP in resource-limited regions and through localized warming "urban heat" contributes to the extension of the growing season in cold regions. In terms of biologically available energy, the loss of NPP due to urbanization of agricultural lands alone is equivalent to the caloric requirement of 16.5 million people, or about 6% of the US population. Numéro de notice : A2004-070 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2003.10.015 En ligne : https://doi.org/10.1016/j.rse.2003.10.015 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26598
in Remote sensing of environment > vol 89 n° 4 (29/02/2004) . - pp 434 - 443[article]Toward universal broad leaf chlorophyll indices using PROSPECT simulated database and hyperspectral reflectance measurements / G. Le Maire in Remote sensing of environment, vol 89 n° 1 (15/01/2004)
[article]
Titre : Toward universal broad leaf chlorophyll indices using PROSPECT simulated database and hyperspectral reflectance measurements Type de document : Article/Communication Auteurs : G. Le Maire, Auteur ; C. François, Auteur ; Eric Dufrêne, Auteur Année de publication : 2004 Article en page(s) : pp 1 - 28 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] albedo
[Termes IGN] chlorophylle
[Termes IGN] erreur moyenne quadratique
[Termes IGN] feuillu
[Termes IGN] indice de végétation
[Termes IGN] réflectance végétale
[Termes IGN] réseau neuronal artificielRésumé : (Auteur) Fifty-three leaves were randomly sampled on different deciduous tree species, representing a wide range of chlorophyll contents, tree ages, and leaf structural features. Their reflectance was measured between 400 and 800 nm with a 1-nm step, and their chlorophyll content determined by extraction. A larger simulated database (11,583 spectra) was built using the PROSPECT model, in order to test, calibrate, and obtain universal indices, i.e., indices applicable to a wide range of species and leaf structure. To our knowledge, almost all leaf chlorophyll indices published in the literature since 1973 have been tested on both databases. Fourteen canonical types of indices (published ones and new ones) were identified, and their wavelengths calibrated on the simulated database as well as on the experimental database to determine the best wavelengths and, hence, the best performances in chlorophyll estimation for each index types. These indices go from simple reflectance ratios to more sophisticated indices using reflectance first derivatives (using the Savitzky and Golay method). We also tested other nondestructive methods to obtain total chlorophyll concentration: SPAD (Minolta Camera, Osaka, Japan) and neural networks. The validity of the actual PROSPECT model is challenged by our results: Important discordances are found when the indices are calculated with PROSPECT compared to experimental data, especially for some indices and wavelengths. The discordance is even greater when the indices are determined with PROSPECT and applied on the experimental database. A new calibration of PROSPECT is therefore necessary for any study aiming at using simulated spectra to determine or to calibrate indices. The "peak jump" and the multiplepeak feature observed on the first derivative of the reflectances (e.g., in the Red-Edge Inflection Point [REIP] index) has been investigated. It was shown that chlorophyll absorption alone can explain this feature. The peak jump disqualifies the REIP to be a valuable chlorophyll index. A simple modified difference ratio gave the best results among all published indices (cross-validated RMSE 2.1 [ug/cm2 on the experimental database). After calibration on the experimental database, modified Simple Ratio (mSR) and modified Nonnalized Difference (mND) indices gave the best performances (RMSECV = 1. 8 ug/cm2 on the experimental database). The new Double Difference (DD) index, although not the best on the experimental database (RMSECV = 2.9 [ug/cm2), has the best results on the larger simulated database (RMSE = 3.7 gg/cm2 ) and is expected to give good results on larger experimental databases. The best reflectance-based indices give better performances than the current commercial nondestructive device SPAD (RMSECV = 4.5 ug/cm2). In this leaf-level study, the best indices are very near from each other, so that complex methods are useless: REIP-like, neural networks, and derivative-based indices are not necessary and give worst results than simpler properly chosen indices. These conclusions will certainly be different for a canopy-level study, where the derivative-based indices may perform significantly better than the other ones. Numéro de notice : A2004-008 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2003.09.004 En ligne : https://doi.org/10.1016/j.rse.2003.09.004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26536
in Remote sensing of environment > vol 89 n° 1 (15/01/2004) . - pp 1 - 28[article]Automated subpixel photobathymetry and water quality mapping / R.L. Huguenin in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 1 (January 2004)
[article]
Titre : Automated subpixel photobathymetry and water quality mapping Type de document : Article/Communication Auteurs : R.L. Huguenin, Auteur ; M.H. Wang, Auteur ; R. Biehl, Auteur ; S. Stoodley, Auteur ; J.N. Rogers, Auteur Année de publication : 2004 Article en page(s) : pp 111 - 123 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] bathymétrie
[Termes IGN] carbone
[Termes IGN] carte thématique
[Termes IGN] chlorophylle
[Termes IGN] classification
[Termes IGN] image Ikonos
[Termes IGN] image multibande
[Termes IGN] lac
[Termes IGN] Massachusetts (Etats-Unis)
[Termes IGN] pollution des eaux
[Termes IGN] précision infrapixellaire
[Termes IGN] profondeur
[Termes IGN] qualité des eaux
[Termes IGN] sédiment
[Termes IGN] turbidité océaniqueRésumé : (Auteur) New photobathymetry and water quality software is described here that utilizes subpixel analysis software (Subpixel Classifier) with an autonomous image calibration procedure and analytic retrieval algorithm to simultaneously retrieve and report bottom depth and the concentrations of suspended chlorophyll, suspended sediments, and colored dissolved organic carbon on a perpixel basis from four-band multispectral image data. From the derived composition, the QSC2 (Quantitative Shoreline Characterization, Version 2.0) software also computes and reports water column visibility parameters (vertical and horizontal subsurface sighting ranges and turbidity, each at four wavelength band passes, plus Secchi depth as a scalar) as well as depth and turbidity confidence. Qsc2 compensates for the effects of the atmosphere, sun and sky reflections from the water surface, subpixel contributions from exposed land, and variations in the bottom material properties. All information is derived automatically from the pixel data alone. The performance of the Qsc2 software was demonstrated using a four-band Ikonos image of Plymouth, Massachusetts. Accuracies of the image-derived compositions, water clarity, and depths were assessed using field and laboratory measurements for eight representative lakes in the scene. The means of the differences of the field-measured and image-derived suspended chlorophyll and colored dissolved organic carbon concentrations for the eight lakes were 1.82 ug/l and 4.34 mgC/1, respectively. The image-derived concentrations of suspended sediments were all below the threshold of detection for the field samples (5 mg/1), in agreement with the field data. The mean of the differences between field-measured and image-derived Secchi depths was 0.76 m. The mean depth difference was 0.57 m. Numéro de notice : A2004-005 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.70.1.111 En ligne : https://doi.org/10.14358/PERS.70.1.111 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26533
in Photogrammetric Engineering & Remote Sensing, PERS > vol 70 n° 1 (January 2004) . - pp 111 - 123[article]Radar imaging of moving targets in foliage using multifrequency multiaperture polarimetric SAR / G. Wang in IEEE Transactions on geoscience and remote sensing, vol 41 n° 8 (August 2003)PermalinkRemote sensing for crop management / P.J. Pinter in Photogrammetric Engineering & Remote Sensing, PERS, vol 69 n° 6 (June 2003)PermalinkRemote sensing techniques to assess water quality / J.C. Ritchie in Photogrammetric Engineering & Remote Sensing, PERS, vol 69 n° 6 (June 2003)PermalinkSchätzung von Vegetationsparametern aus multispektralen Fernerkundungsdaten / F. Kurz (2003)PermalinkAssessment of regional forest and scrub productivity using a coupled vegetation process model with remote sensing / Nicholas C. Coops in Geocarto international, vol 17 n° 4 (December 2002 - February 2003)PermalinkThe effect of broadleaf canopies on survey-grade horizontal GPS-GLONASS measurements / Thomas H. Meyer in Surveying and land information systems, vol 62 n° 4 (01/12/2002)PermalinkLeaf morphological differentiation between Quercus robur and Quercus petraea is stable across western European mixed oak stands / Antoine Kremer in Annals of Forest Science, vol 59 n° 7 (novembre 2002)PermalinkImprovement of an oak canopy model extracted from digital photogrammetry / P. Gong in Photogrammetric Engineering & Remote Sensing, PERS, vol 68 n° 9 (September 2002)PermalinkApprofondissement des techniques de diagnostique des propriétés spectrales d'une culture / Laure Chandelier (2002)PermalinkUtilisation des images et données multisources pour caractériser l'état de palmeraies industrielles au Gabon / Marcellin Nziengui (2000)Permalink