滇中典型乔木植被高光谱特征

针对滇中乔木植被光谱研究较少问题,运用高光谱遥感技术提取分析植被的特征波段,补充滇中乔木光谱,以期能为遥感识别分类植被、监测乔木长势,以及植被反演等提供科学依据。利用SOC710VP地物光谱仪,对滇中的侧柏(Platycladus orientalis)、樟木(Cinnamomum longepaniculatum)、柳杉(Cryptomeria fortunei)3种植被进行反射光谱测定,分析3种植被的叶片光谱特征差异,使用光谱一阶导数和连续统去除处理其原始光谱。原始反射率曲线表明,400~420 nm柳杉的曲线呈下降趋势,区别于樟木和侧柏;侧柏、樟木、柳杉的反射率在700~760 nm存在显著差异。红边波段光谱一阶导数凸显了3种乔木植被特有的波峰波谷特征,侧柏的峰谷特征尤其突出,识别度更大。连续统去除变换能够突出3种乔木植被在可见光波段的吸收和反射特征差异,樟木和柳杉的连续统去除值在440~760、950~1 000 nm存在较大差异。通过比较3种植被的原始光谱特性和反射率,可以从一定程度上把3种植被区分开。光谱一阶导数和连续统去除变换可以突出3种植被原始光谱特征之外的特征,增加识别分类3种植被的特征波段,区分识别3种植被的效果更显著。

Hyperspectral characteristics of typical tree vegetation in central Yunnan

Using the hyperspectral remote sensing technology to extract and analyze the characteristic bands of vegetation to solve the problem of less research on tree vegetation spectrum in central Yunnan, which could be used to supplement the spectrum of tree in central Yunnan Province and provide scientific basis in identifying vegetation classification, monitoring tree growth and vegetation inversion for remote sensing. Three vegetation of Platycladus orientalis, Cinnamomum longepaniculatum and Cryptomeria fortunei in central Yunnan Province were measured in reflective spectrum by using SOV710VP surface spectrometer to analyze the difference of leaf spectral characteristics of the three vegetation, and then the original spectrum of three vegetation were processed and analyzed by using the first derivative of spectrum and continuum removal method. The original reflectance curve showed that the curve of Cryptomeria fortunei showed a downward trend in the range of 400 nm to 420 nm, which was different from Cinnamomum longepaniculatum and Platycladus orientalis. There were significant differences in reflectance values of the three vegetation between 700 nm to 760 nm. The first-order derivative of the red band spectrum highlighted unique characteristics of the peaks and valleys of three tree vegetation. The peak-valley characteristic of Platycladus orientalis was particularly prominent and the recognition was more obvious. The continuum removal transformation could highlight the differences in absorption and reflection characteristics of the three tree vegetation in the visible light band. The continuum removal values of Cinnamomum longepaniculatum and Cryptomeria fortunei varied greatly in the range of 440-760 nm and 950-1 000 nm. To a certain extent, the three vegetation could be distinguished by analyzing and comparing the original spectral characteristics and reflectivity values of the three vegetation. Through the first derivative and continuum removal transformation of spectrum, other features besides the original spectral features could be highlighted, and the characteristic band for distinguishing the three vegetation was added, which had a more remarkable effect for distinguishing and identifying the three vegetation.