不同氮运筹模式冬小麦LAI光谱特征波段提取

摘要

叶面积指数(LAI)是评价作物冠层结构的重要参数之一,利用光谱技术实现冬小麦LAI的快速、准确监测具有重要的意义.连续2a进行氮素运筹试验,通过测定各生育时期的光谱反射率和LAI,并基于偏最小二乘法-逐步多元线性回归(PLS-SMLR)统计学方法,提取各氮素运筹条件下LAI特征波段.结果表明,不同氮运筹条件下LAI的特征波段存在差异;同一施氮量,低基追肥比,特征波段前移,通过提取的波段预测LAI精度较高.表明利用PLS-SMLR提取不同氮运筹条件下的冬小麦LAI特征波段是可行的.%Leaf area index (LAI) is one of the important parameters to evaluate crop canopy structure,and the rapid,real-time and nondestructive technology of hyperspectral remote sensing is widely apphed on monitoring the LAI.In the study,the canopy spectral reflectance and LAI of winter wheat under different nitrogen applications during 2012-2014 were measured.The characteristic wavelengths were extracted by using multivariate methods.The results showed that characteristic wavelengths of LAI were different under different nitrogen managements,and wavebands moved forward with lower proportion of basis and additional fertilizer,the predictive of LAI was high by characteristic wavelengths.It meant that these were feasible for extracting characteristic wavelengths the LAI of winter wheat under different nitrogen applications by PLS-SMLR.