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Assessing the potential of SeaWiFS and MODIS for estimating chlorophyll concentration in turbid productive waters using red and near-infrared bands / G. Dall'olmo in Remote sensing of environment, vol 96 n° 2 (30/05/2005)  

Public [article]  inRemote sensing of environment > vol 96 n° 2 (30/05/2005) . - pp 176 - 187 Titre : Assessing the potential of SeaWiFS and MODIS for estimating chlorophyll concentration in turbid productive waters using red and near-infrared bands Type de document : Article/Communication Auteurs : G. Dall'olmo, Auteur ; A. Gitelson, Auteur ; et al., Auteur Année de publication : 2005 Article en page(s) : pp 176 - 187 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] bande rouge [Termes IGN] chlorophylle [Termes IGN] image Aqua-MODIS [Termes IGN] image Seawifs [Termes IGN] lac [Termes IGN] rayonnement proche infrarouge [Termes IGN] réflectance [Termes IGN] turbidité des eaux Résumé : (Auteur) Bio-optical algorithms for remote estimation of chlorophyll-a concentration (Chl) in case-1 waters exploit the upwelling radiation in the blue and green spectral regions. In turbid productive waters other constituents, that vary independently of Chl, absorb and scatter light in these spectral regions. As a consequence, the accurate estimation of Chl in turbid productive waters has so far not been feasible from satellite sensors. The main purpose of this study was to evaluate the extent to which near-infrared (NIR) to red reflectance ratios could be applied to the Sea Wide Field-of-View Sensor (SeaWiFS) and the Moderate Imaging Spectrometer (MODIS) to estimate Chl in productive turbid waters. To achieve this objective, remote-sensing reflectance spectra and relevant water constituents were collected in 251 stations over lakes and reservoirs with a wide variability in optical parameters (i.e. 4 Numéro de notice : A2005-264 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2005.02.007 En ligne : https://doi.org/10.1016/j.rse.2005.02.007 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27400 [article]

AVHRR-based spectral vegetation Index for quantitative assessment of vegetation state and productivity: calibration and validation / F. Kogan in Photogrammetric Engineering & Remote Sensing, PERS, vol 69 n° 8 (August 2003)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 69 n° 8 (August 2003) . - pp 899 - 906 Titre : AVHRR-based spectral vegetation Index for quantitative assessment of vegetation state and productivity: calibration and validation Type de document : Article/Communication Auteurs : F. Kogan, Auteur ; A. Gitelson, Auteur ; E. Zakarin, Auteur ; L. Spivak, Auteur ; L. Lebed, Auteur Année de publication : 2003 Article en page(s) : pp 899 - 906 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] Advanced Very High Resolution Radiometer [Termes IGN] étalonnage en vol [Termes IGN] gestion des ressources [Termes IGN] indice de végétation [Termes IGN] Normalized Difference Vegetation Index [Termes IGN] tronc Résumé : (Auteur) The goal of the work was to estimate, quantitatively, vegetation state and productivity using AVHRR based Vegetation Condition Index (VCI). The VCI algorithm includes application of postlaunch calibration to visible channels, calculation of NDVI from channels' reflectance, removal of high frequency noise from NDVI's annual time series, stratification of ecosystem resources, and separation of ecosystem and weather components in the NDVI value. The weather component was calculated by normalizing the NDVI to the difference of the extreme NDVI fluctuations (maximum and minimum), derived from multiyear data for each week and land pixel. The VCI was compared with wheat density measured in Kazakhstan. Six test fields were located in different climatic (annual precipitation 150 to 700 mm) and ecological (semi desert to steppe forest) zones with elevations from 200 to 700 m and a wide range of NDVI variation over space and season from 0.05 to 0.47. Plant density (PD) was measured in wheat fields by calculating the number of stems per unit area. PD deviation from year to year (PDD) was expressed as a deviation from median density calculated from multiyear data. The correlation between PDD and VCI all stations was positive and quite strong (r2 > 0.75) with the Standard Errors of Estimates (SEE) of PDD less than 16 percent ; for individual stations, the SEE was less than 11 percent. The results indicate that VCI is an appropriate index for monitoring weather impact on vegetation and for assessment of pasture and crop productivity in Kazakhstan. Because satellite observations provide better spatial and temporal coverage, the VCI based system will provide efficient tools for management of water resources and the improvement of agricultural planning. This system will serve as a prototype in the other parts of the world where ground observations are limited or not available. Numéro de notice : A2003-170 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.14358/PERS.69.8.899 En ligne : https://doi.org/10.14358/PERS.69.8.899 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22466 [article]