Liang Liang, Yang Min-Hua, Zhang Lian-Peng, Lin Hui
School of Geodesy and Geomatics of Xuzhou Normal University, Xuzhou 221116, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2011 Jun;31(6):1658-62.
The wheat leaf area index (LAI) was inverted using hyperspectral remote sensing technology in the present paper. Eighteen kinds of hyperspectral indices were comparatively analyzed, and the index OSAVI, which could reflect wheat LAI most sensitively, was screened out. The models for wheat LAI inversion were built using the field spectra as the training samples. The study showed that the calibration R-square and prediction R-square of the inversion model which were built by hyperspectral index OSAVI were 0.823 and 0.818, respectively, higher than that of other indices, indicating that the accuracy was highest. The inversion model was spatially quantitatively expressed in OMIS image, and then the inversion value and measured value was compared by the method of regression fitting. The R-square and RMSE of the fitting model were 0.756 and 0.500, respectively, indicating that the similarity between the inversion value and measured value was high. The result showed that it was feasible to invert the wheat LAI by hyperspectral indices, and OSVAI was an optimal one.
本文利用高光谱遥感技术反演小麦叶面积指数(LAI)。对18种高光谱指数进行了比较分析,筛选出对小麦LAI反映最敏感的指数OSAVI。以田间光谱为训练样本建立了小麦LAI反演模型。研究表明,利用高光谱指数OSAVI建立的反演模型的校正决定系数和预测决定系数分别为0.823和0.818,高于其他指数,表明其精度最高。将反演模型在OMIS图像上进行空间定量表达,然后采用回归拟合的方法对反演值和实测值进行比较。拟合模型的决定系数和均方根误差分别为0.756和0.500,表明反演值与实测值之间的相似度较高。结果表明,利用高光谱指数反演小麦LAI是可行的,且OSVAI是最优指数。