caa a22 4500 467904952 CHVBK 20180406152831.0 cr unu---uuuuu 170328e20060901xx s 000 0 eng 10.1007/s10661-005-9052-1 doi (NATIONALLICENCE)springer-10.1007/s10661-005-9052-1 Hyperspectral Characteristics of Canopy Components and Structure for Phenological Assessment of an Invasive Weed [Elektronische Daten] [Shaokui Ge, James Everitt, Raymond Carruthers, Peng Gong, Gerald Anderson] Spectral reflectance values of four canopy components (stems, buds, opening flowers, and postflowers of yellow starthistle (Centaurea solstitialis)) were measured to describe their spectral characteristics. We then physically combined these canopy components to simulate the flowering stage indicated by accumulated flower ratios (AFR) 10%, 40%, 70%, and 90%, respectively. Spectral dissimilarity and spectral angles were calculated to quantitatively identify spectral differences among canopy components and characteristic patterns of these flowering stages. This study demonstrated the ability of hyperspectral data to characterize canopy components, and identify different flowering stages. Stems had a typical spectral profile of green vegetation, which produced a spectral dissimilarity with three reproduction organs (buds, opening flowers, and postflowers). Quantitative differences between simulated flower stages depended on spectral regions and phenological stages examined. Using full-range canopy spectra, the initial flowering stage could be separated from the early peak, peak, and late flowering stages by three spectral regions, i.e. the blue absorption (around 480 nm) and red absorption (around 650 nm) regions and NIR plateau from 730 nm to 950 nm. For airborne CASI data, only the red absorption region and NIR plateau could be used to identify the flowering stages in the field. This study also revealed that the peak flowering stage was more easily recognized than any of the other three stages. Springer Science+Business Media, Inc., 2006 invasive species nationallicence Centaurea solstitialis nationallicence spectral characteristics nationallicence flowering phenological stages nationallicence hyperspectral remote sensing nationallicence Ge Shaokui Center for Assessment and Monitoring of Forest and Environmental Resources, University of California, Berkeley, California, U.S.A. aut Everitt James USDA ARS, Kika de la Garza Subtropical Agricultural Research Center, Integrated Farming and Natural Resources Research Unit, 2413 E Hwy 83, Weslaco, Texas, U.S.A. aut Carruthers Raymond Exotic and Invasive Weeds Research Unit, Western Regional Research Center Agricultural Research Service, USDA, 800 Buchanan Street Albany, California, U.S.A. aut Gong Peng Center for Assessment and Monitoring of Forest and Environmental Resources, University of California, Berkeley, California, U.S.A. aut Anderson Gerald USDA Agricultural Research Service, Northern Plains Area, 1500 North Central Avenue, Sidney, Montana, Sidney aut Environmental Monitoring and Assessment Kluwer Academic Publishers 120/1-3(2006-09-01), 109-126 0167-6369 120:1-3<109 2006 120 10661 https://doi.org/10.1007/s10661-005-9052-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10661-005-9052-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ge Shaokui Center for Assessment and Monitoring of Forest and Environmental Resources, University of California, Berkeley, California, U.S.A aut NATIONALLICENCE 700 1- Everitt James USDA ARS, Kika de la Garza Subtropical Agricultural Research Center, Integrated Farming and Natural Resources Research Unit, 2413 E Hwy 83, Weslaco, Texas, U.S.A aut NATIONALLICENCE 700 1- Carruthers Raymond Exotic and Invasive Weeds Research Unit, Western Regional Research Center Agricultural Research Service, USDA, 800 Buchanan Street Albany, California, U.S.A aut NATIONALLICENCE 700 1- Gong Peng Center for Assessment and Monitoring of Forest and Environmental Resources, University of California, Berkeley, California, U.S.A aut NATIONALLICENCE 700 1- Anderson Gerald USDA Agricultural Research Service, Northern Plains Area, 1500 North Central Avenue, Sidney, Montana, Sidney aut NATIONALLICENCE 773 0- Environmental Monitoring and Assessment Kluwer Academic Publishers 120/1-3(2006-09-01), 109-126 0167-6369 120:1-3<109 2006 120 10661 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer