松材线虫病害高光谱时序与敏感特征研究

采用高光谱仪ASD FieldSpec Pro FR,连续观测了健康和发病马尾松针叶的时序高光谱,分析了松材线虫病害光谱的时序特征、敏感时期和敏感特征。结果表明:与健康马尾松相比,病害马尾松时序光谱差异较大;病害首先造成红边区域内光谱反射率减低,然后再出现红边蓝移的2阶段光谱变化规律;感染松材线虫的马尾松9月初已经出现了病态植被典型的光谱特征;近红外平台内最大的一阶微分值、红边内一阶微分的总和(SDr)与蓝边内一阶微分的总和(SDb)的比值等是指示病害发生的显著性高光谱特征。

Study on Pine Wilt Disease Hyper-spectral Time Series and Sensitive Features

Ground spectrometer ASD FieldSpec Pro FR was applied to sequentially measure the spectra of healthy and withered mason pine needles.Time series analysis of spectra,a sensitive period and sensitive characteristics identification were conducted in the study.This paper showed that compared with the regular spectral series of healthy mason pine,the spectral series of mason pine infected by pine wood nematode (PWD) appeared none regularity.Through time series analysis of spectral derivative of PWD,we found that two phases spectral variation were showed,first,the spectral reflectance reduced in the red edge,and then the blue edge shift to red edge.In the early September,the mason pine infected by PWD have shown the typically spectral characteristics of pathological vegetation.Finally,by comparing the rate of change in defined hyper-spectral parameter values,the largest first order differential valves within near-infrared spectrum,and the ratio of first order differential sum in the red edge (SDr) to first order differential sum in the blue edge (SDb) are significant indicatives of PWD occurrence.