叶片随着时间生长产生变化, 其光谱特征也会发生变化。 研究相同树种叶片不同时间条件下的光谱变化规律以及不同树种叶片相同时间条件下的光谱特征, 不仅为植被叶片光谱随时间变化的规律研究提供理论基础, 也是高光谱遥感精确识别植被信息的关键。 选取北京市10种常见树种, 利用地物光谱仪观测各树种不同时间叶片光谱, 同时将观测的光谱进行一阶微分处理和典型波段分析, 对比相同时间不同树种叶片光谱的差异, 分析相同树种不同时间的光谱变化规律, 探索不同时相条件下高光谱遥感识别树种的有效波段。 结果表明: 不同树种叶片光谱均随时间的改变而产生显著变化, 但差异规律各不相同; 不同树种相同时间叶片光谱在部分波段存在显著差异, 为高精度树种识别提供了理论依据和叶片基础光谱数据。

Leaf growth will change along with time, so species spectral characteristics will be affected. The researches on spectral changing rule of the same tree leaf under the conditions of different time and spectral characteristics of different tree leaves under the condition of the same time can not only provide theoretical basis for vegetation leaf spectral change rule along with time, but also are the keys of vegetation information accurate identification with hyperspectral remote sensing. Ten kinds of common tree species in Beijing were selected and leaf spectrum of each tree species in different time was observed by using spectrometer. At the same time, the observed spectrum was dealt with first order differential and typical bands analysis. Then spectrum difference of different tree leaves at the same time were contrasted and spectrum change laws of the same species in different time were analyzed, and the effective bands of species identification by hyperspectral remote sensing under the condition of different time were explored. The results showed that the leaf spectrum of different tree species had significant changes along with time but the changing rules were different, and there were significant differences among different tree species leaves spectrum in the same time, so it proved a theoretical basis for high precision tree species identification. This study aims at providing basic data and theoretical support for tree species identification of hyperspectral remote sensing and the building of leaf spectrum base database.