混合光谱分解模型提取水体叶绿素含量的研究

Study on Spectral Unmxing Model and It's Application in Extracting Chlorophyll Concentration of Water Body

遥感监测水体叶绿素含量是水质遥感研究的难点之一。本文通过研究不同叶绿素含量水体反射率的光谱特征,确定了提取叶绿素a含量的最佳特征波段,建立了太湖水体叶绿素a的混合光谱模型。研究发现,混合光谱模型提取的水体叶绿素a百分比浓度与同步采样分析的叶绿素a浓度之间有较好的线性相关性。并基于TM和HEPER ION图像利用此模型生成了叶绿素a浓度分布图。研究结果表明,混合光谱分解模型可以作为遥感监测水体叶绿素a含量的定量模型。

Remote sensing（RS） data can be used to estimate the chlorophyll-a concentration of water body, which has become a key issue of water quality monitoring. In this paper the field water reflectance spectra have been applied for monitoring the water quality of Taihu Lake according to reflectance spectra of water garying with concentrations of organic and inorganic sediments. After analyzing the spectra character we selected the optimal band range （670--710nm）, and retrieved the chlorephyll-a concentration by linear spectral unmixing model using known water and chlorephyll-a endmember spectra of in situ-water samples. TM and HEPERION image was processed and the distribution of chlorephyll-a concentration was retrieved by linear spectral unmixing method. The result shows that a fine linear correlation exists between the abundance of chlorophyll-a from the spectral unmixing model and the concentration of chlorephyll-a from the analytical result in the laboratory ,and also shows that spectral unmxing model is a feasible model in the practical application for water quality monitoring.