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基于吸收、透射和反射光谱预测水稻叶绿素含量研究 总被引：1，自引：0，他引：1
选择基于吸收率和透射率的叶绿素含量定量反演波段组合,构建叶绿素含量光谱估测模型寻找基于吸收、透射和反射光谱预测叶绿素含量的波段。以3个水稻品种临稻11,圣稻13和阳光200为材料,进行田间实验。比较水稻叶片吸收、反射及透射光谱曲线和一阶导数光谱曲线,发现440、480、630nm和681nm为叶绿素吸收峰的实际发生波段位置,其中630nm波段处的叶片光谱吸收率(A)、透射率(T)和反射率(R)之间相关性最好。比较三者之间的相关性,吸收率与透射率的相关性最强。630nm波段处的叶片光谱吸收率、透射率和反射率与叶绿素含量之间的相关性均达到极显著水平。回归分析表明基于440、480nm和681nm3个波段光谱吸收率线性模型,440、480nm和630nm3个波段光谱透射率线性模型估测叶绿素a含量,480、630nm和681nm3个波段光谱透射率线性模型估测叶绿素b含量,与单独使用630nm光谱变量估测叶绿素含量比较,在4个生育期估测精度均有显著提高,其中以叶绿素a和叶绿素总量的估测效果最好。 相似文献
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SO2毒害水稻叶片吸收光谱植被指数研究 总被引：2，自引：1，他引：1
为寻找对SO_2伤害敏感的叶片吸收光谱植被指数,通过田间熏气试验对水稻叶片吸收光谱与叶绿素总量、熏气浓度的相关性进行了研究.结果表明,由吸收光谱曲线及其一阶导数光谱曲线的特征位置确定的分别位于蓝光区、黄光区和红光区的12个特征波段的叶片吸收光谱值均与叶绿素总量显著相关,由这些特征波段构建的植被指数BEACI/YEACI/REACI与叶绿素总量的相关性都达到极显著水平,并且相关系数比特征单波段吸收光谱值与叶绿素总量的相关性显著提高.进一步分析这些植被指数与SO_2熏气浓度之间的相关性表明,最新完全展开叶在663.239、693.460 nm的单波段吸收光谱以及植被指数BEACI、REACI、YEA CI613.385、YEACI_(630.036)和YEACI_(663.239)与SO_2熏气浓度呈正显著相关.BEACI、REACI,、YEACI_(613.385)、YEACI_(630.036)和YEACI_(663.229)为叶片吸收光谱SO_2伤害敏感植被指数,具有估测水稻SO_2伤害的应用潜力. 相似文献
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Changes in ultraviolet-B and visible optical properties and absorbing pigment concentrations in pecan leaves during a growing season 总被引：1，自引：0，他引：1
UV-B (280–320 nm) and visible (400–760 nm) spectral reflectance, transmittance, and absorptance; chlorophyll content; UV-B absorbing compound concentration; and leaf thickness were measured for pecan (Carya illinoensis) leaves over a growing season (April–October). Leaf samples were collected monthly from a pecan plantation located on the Southern University Horticultural Farm, Baton Rouge, Louisiana. The leaf spectral reflectance and transmittance were measured from 280 to 760 nm using a high-accuracy UV-Vis spectroradiometer with an integrating sphere. The spectral absorptance was calculated based on the reflectance and transmittance percentages. Total UV-B absorbing compounds concentration (A280–320 nm (cm−2)), chlorophyll content, and leaf thickness were related to the leaf optical properties. The patterns of the spectral distributions of optical properties over the growing season, effects of leaf age on the measured parameters, and their relationships were determined. Leaf optical properties were significantly affected by leaf age and the effects were more dramatic in the visible spectral region than in the UV-B region. Within the UV-B spectral region, leaf reflectance ranged between 4.27% (April) and 8.29% (July), transmittance between 0.01% (June) and 0.05% (April), and absorptance between 91.70% (July) and 95.68% (April). Within the visible spectral region, leaf optical properties changed significantly with the wavelength and leaf development. The visible spectral reflectance and transmittance had maxima at 555 nm and minima at 680 nm, and increased sharply afterwards. The highest visible spectral reflectance and transmittance occurred in the newly developed leaves, whereas the visible spectral absorptance increased with leaf maturation. Leaf chlorophyll content, thickness, and UV-B absorbing compound concentration significantly increased during leaf development (April–July). Correlation and regression analyses indicated that leaf chlorophyll content was a strong predictor of the green light reflectance, transmittance, and absorptance. The strongest predictors of UV-B reflectance were leaf thickness and leaf UV-B absorbing compound concentrations. 相似文献
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用反射率、透射率和吸收率分析玉米叶片水分含量时的峰值波长选择 总被引：4，自引：1，他引：4
通过测定田间试验条件下11个玉米品种、3个氮肥处理、2个密度处理和4个生育期的100张叶片的反射、透射和吸收光谱(350～2500 nm)，发现玉米叶片在近红外和短波红外的水分吸收区域的反射/透射/吸收的中心峰值波长实际发生在974 nm、1160 nm和1440 nm，在这3个峰值波长，叶片反射率、吸收率与叶片水分含量之间的相关性好于透射率。在这3个峰值波长中，反射率、透射率和吸收率相互之间的关系以1440 nm为最紧密，在此波长光谱与叶片水分含量之间的相关性也相对较强。因此，1440 nm是用叶片反射率和吸收率反演植物的水分状况的最佳峰值波长。 相似文献
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《Plant Production Science》2013,16(4):269-279
AbstractSpectral reflectance of differentially-managed rice canopies was measured over an entire growing season and analyzed with special attention to linking remotely sensed information with a simple growth model. The fraction of absorbed photosynthetically active radiation (fAPAR), which is often used as a key variable in simple process models, was well correlated writh spectral vegetation indices (VI). VIs, such as NDVI and SAVI, were derived from the ratio of reflectance at two wavelengths (R660 nm and R830 nm) and a new VI, termed the normalized difference ND [R1100 nm, R660 nm], was derived from the difference of Rl 100 nm and R660 nm divided by their sum. These close relations between fAPAR and Vis were expressed by exponential formulae with different parameters for the periods before and after heading. These indices became less sensitive to fAPAR when fAPAR was larger than 0.4. The use of R1100 nm and R1650 nm with R660 nm and R830 nm in multiple regression significantly improved the prediction accuracy of fAPAR. A close linear relation was found between a spectral ratio R830 nm/R550 nm and leaf nitrogen content during the ripening period although it was not the case before heading. Results suggested that R830 nm/R550 nm was effective for estimation of leaf nitrogen content when the paddy field was regarded as a big leaf. The total amount of leaf nitrogen was well correlated with ND [R1100 nm, R660 nm] ; nevertheless, the sensitivity was lost when the total amount of leaf nitrogen was greater than 3 g m?2. Multiple regression analysis showed that a combination of four spectral bands R550 nm, R830 nm, R1650 nm and R2200 nm was useful for estimation of the total amount of leaf nitrogen. Remotely-sensed nitrogen variables would be a potential model parameters in a simple model. A real-time recalibration module based on a simplex algorithm was developed and proved effective in linking the remotely-sensed fAPAR with a simple model. This approach was also useful for inferring the physiological parameters such as radiation use efficiency for each rice canopy without destructive sampling. The re-parameterization and/or re-initialization with remotely-sensed information was demonstrated to be a practical and effective approach, especially for operational purposes. 相似文献
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为寻找对SO2伤害敏感的叶片吸收光谱植被指数,通过田间熏气试验对水稻叶片吸收光谱与叶绿素总量、熏气浓度的相关性进行了研究。结果表明,由吸收光谱曲线及其一阶导数光谱曲线的特征位置确定的分别位于蓝光区、黄光区和红光区的12个特征波段的叶片吸收光谱值均与叶绿素总量显著相关,由这些特征波段构建的植被指数BEACI/YEACI/REACI与叶绿素总量的相关性都达到极显著水平,并且相关系数比特征单波段吸收光谱值与叶绿素总量的相关性显著提高。进一步分析这些植被指数与SO2熏气浓度之间的相关性表明,最新完全展开叶在663.239、693.460 nm的单波段吸收光谱以及植被指数BEACI、REACI、YEACI613.385、YEACI630.036和YEACI663.239与SO2熏气浓度呈正显著相关。BEACI、REACI、YEACI613.385、YEACI630.036和YEACI663.239为叶片吸收光谱SO2伤害敏感植被指数,具有估测水稻SO2伤害的应用潜力。 相似文献
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