小球藻和铜绿微囊藻的高浓度Chl-a高光谱定量模型

本研究将地物高光谱遥感技术应用于室内实验,从而得到小球藻和铜绿微囊藻的高光谱特征.通过多种半经验方法,如单波段、波段比值和微分法,建立了两藻种最优的Chl-a高光谱定量模型,并与室外情况进行了对比.结果表明:小球藻的最优定量模型为Chl-a=174.6 1138292(R703) 2.3(109(R703)]2(p＜0.01),相应的方法适宜性为:一阶微分法＞单波段法＞波段比值法;铜绿微囊藻的最优定量模型为Chl-a=5299164(R757)1.9773(p＜0.01),相应的方法适宜性为:单波段法＞波段比值法＞一阶微分法;从高光谱特征来看,小球藻在540 nm和700 nm附近存在明显的特征波峰,其位置随Chl-a浓度增大而向长波方向偏离,铜绿微囊藻在530 nm、660 nm和700 nm附近存在3个较强的特征波峰,在610 nm和680 nm附近存在明显的波谷;与以往室外研究不同的是铜绿微囊藻的反射率在400-500 nm之间的R值并不低,是因为没有非藻类颗粒物的影响,总吸收明显降低.

Hyperspectral quantitative models for Chlorophyll-a of Chlorella vulgaris and Microcystis aeruginosa

Based on hyperspectral remote sensing measurement for Chlorella vulgaris and Microcystis aeruginosa, this in situ experiment addressed the hyperspectral characteristics of Chlorella vulgaris and Microcystis aeruginosa and determined their optimal hyperspectral quantitative models of chlorophyll-a (Chl-a) estimation.The study demonstrated that:(1)The optimal hyperspectral quantitative model of Chlorella vulgaris was Chl-a=174.6+1138292(R₇₀₃)'+2.3(10⁹(R₇₀₃']²(p<0.01), and the suitability order of corresponding methods was spectral ratio > single band > reflectance first-derivative;the optimal hyperspectral quantitative model of Microcystis aeruginosa was Chl-a=5299164(R757)^1.9773(p<0.01), and the suitability order of corresponding methods was single band > reflectance first-derivative > spectral ratio;(2) According to hyperspectral characteristics of Chlo-rella vulgaris, two reflectance crests were around 540 nm and 700 nm and their locations moved right while Chl-a concentrations increased.For Microcystis aeruginos, three reflectance wave crests were around 530 nm, 660 nm and 700 nm while two troughs were near 610 nm and 680 nm;(3) Compared with results of previous outdoor researches, the Microcystis aeruginos reflectance with wavelength between 400 nm and 500 nm was relatively bigger, as for suspended substance and CDOM didnf exist in this indoor experiment.