由吸收系数和粒度分布计算浮游植物的散射光谱特征

散射特性在水色卫星遥感模式的开发、水下光辐射传输、优势藻光谱特征的提取以及赤潮监测等方面有着重要的应用价值.在假定藻细胞为均匀球形结构的条件下,建立了浮游植物的散射正演模型.模型输入参量为实际测量的藻细胞吸收系数和粒度分布,输出参量为浮游植物的散射效率和吸收效率光谱.对短伪海链藻和威氏海链藻进行实验,模拟结果与实验结果的比较发现:该模型估箅得到的散射光谱能与实验的散射光谱得到很好的吻合,两种藻的模拟散射效率相对实验散射效率的误差分别为7%和10.6%,吸收效率的误差分别为7.4%和13.4%.模拟与实验结果的吻合表明,由吸收系数和粒度分布可以模拟出藻类的散射光谱特性.单细胞近似球形藻类散射正演模型可行.

Spectral Scattering Property of Phytoplankton Calculated by Absorption Coefficient and Size Distribution

Property scattering is of important value in development of ocean color remote sensing algorithms, underwater radiative transfer, spectral information extraction of dominated algae, red tide monitoring, etc.. The theoretical model is proposed to predict the scattering and absorption efficiency factors of phytoplankton from absorption spectrum and size distribution of phytoplankton for spherical and homogeneous algal cells. The input parameters are the measured absorption coefficient and size distribution, and the output parameters are the spectral efficiency factors for scattering and absorption. The theoretical predictions for Thalassirosira pseudonana and Thalassirosira weissflogii are compared to experimental results. A rough agreement is shown between the theoretical and experimental spectral efficiency factors, and the relative deviations between modeled and measured scattering efficiency factors are only 7% for T.pseudonana and 10.6% for T.weissflogii, and 7.4% and 13.4% respectively between absorption efficiency factors. The agreements indicate that scattering property of phytoplankton can be modeled from the absorption coefficient and size distribution, and the theoretical model may be available for modeling scattering spectral property of approximate spherical algal cells.