基于实测光谱的红花叶绿素含量高光谱估算模型研究

Hyperspectral Estimation Models for Chlorophyll Content Based on the Measured Spectra of Safflower

通过分析红花(Carthamus tinctorius L.)原始光谱、变换光谱以及其他25种应用最普遍的高光谱参数与其叶绿素含量的相关性,并选择每个生长期与红花叶绿素含量相关性较好的高光谱指数和波段,建立不同生长期红花叶绿素含量的线性、抛物线、指数和对数模型,并用RMSE评价模型精度。最后得出各期的最佳模型:出苗期归一化差异指数(NDI)的抛物线模型具有最大模型精度0.900和检验精度0.932;分枝期黄边幅值(Dy)的抛物线模型精度为0.850,检验模型精度为0.811;始花期444 nm处二阶导数光谱的抛物线模型精度为0.734,检验精度为0.866;终花期798 nm处二阶导数光谱的抛物线模型精度为0.929;成熟期795 nm处二阶导数光谱的指数模型精度为0.904,检验精度为0.868。

In order to establish linear and parabolic, index and logarithm model of safflower（Carthamus tinctorius L.） chlorophyll content,the correlation of original spectra, transform spectra,and 25 kinds of most common hyperspectral application parameters and chlorophyll content in different stages were analyzed. The high spectral indexes and wavelengths having good correlation with the chlorophyll content of safflower during every growing period were selected. RMSE were used for appraising the model precision. Finally the best models of different periods were gotten,during the seedling stage,the largest model precision and test precision were 0.900 and 0.932 respectively for the parabolic model of NDI. During the branch period,the model precision and test precision were 0.850 and 0.811 respectively for the parabolic model of Dy. During the beginning flowering period,the model precision and test precision were 0.734 and 0.866 respectively for the parabolic model of the second derivative spectra at the wavelength 444 nm. During the final flowering period,the model precision was 0.929 for the parabolic model of the second derivative spectra at the wavelength 798 nm. During the mature period,the model precision and test precision were 0.904 and 0.866 respectively for the index model of the second derivative spectra at the wavelength 795 nm.