摘要
根据理论分析作出了小麦叶片7种角度分布情况下的光谱植被指数和吸收的光合辐射曲线以及叶面指数和吸收的光合辐射曲线。由实测的小麦光谱反射率数据计算出光谱植被指数,再使用这二套理论曲线可求出小麦的叶面指数。还作出了叶片7种角度分布下,小麦叶面指数计算值和测量值之间的线性回归方程,得出小麦叶片倾角为70°的分布和使用 ND 光谱指数具有最好的结果。
The relationship between spectral vegetation indexes,leaf area index(LAI)and photosynthetically active radiation(PAR)were studied under seven types of leaf angle distribution in wheat.The computed spectral vegeta- tion indexes,based on practical observation,were used to estimate LAI accor- ding to the theoreLical relation.The estimated and observed LAI were compar- ed and Lhe linear regression models were established under seven types of leaf angle in wheat.The result showed that using normalized difference vegetation index(ND)to estimate LAI is better than other vegetation indexes when leaf angle is 70℃ in wheat.
关键词
光谱反射率
叶面指数
回归方程
spectral reflectance
leaf area index
regression modle
