DETECTION OF SPAD VALUE OF CUCUMBER LEAVES BASED ON VISIBLE/NEAR INFRARED SPECTROSCOPY TECHNIQUE
DETECTION OF SPAD VALUE OF CUCUMBER LEAVES BASED ON VISIBLE/NEAR INFRARED SPECTROSCOPY TECHNIQUE
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基于可见/近红外光谱技术的黄瓜叶片花萼值检测
DOI：
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发表时间：
2009
影响因子：
0.7
通讯作者：
Wang Li
中科院分区：
文献类型：
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作者：
He Yong;Liu Fei;Bao Yi-Dan;Wang Li
为了快速检测黄瓜叶片的SPAD值，采用可见光和近红外（Vis/NIR）光谱技术和化学计量学方法建立了SPAD值的标定模型。采用不同的标定方法在整个波长区域建立模型。结果表明，最小二乘支持向量机（LSSVM）模型具有最佳的预测性能，预测相关系数(r)和均方根误差（RMSEP）分别为0.9583和0.9732。通过分析光谱反射率与SPAD值的相关系数以及偏最小二乘（PLS）回归系数，得到两个特征波长波段（531~581nm和696~716nm）和四个特征波长（556,581,698和715nm）。LSSVM使用了上述波长波段和波长。结果表明，在r为0.9338、RMSEP为1.1370的条件下，该特征波段具有较好的性能。预测结果与全波长区域模型基本一致，而包含四个特征波长的LSSVM模型的预测效果不理想。利用特征波段的校准方法可以大大减少校准计算量，提高校准速度。因此，利用特征波长波段检测黄瓜叶片的SPAD值更为有效。
For the rapid detection of SPAD value of cucumber leaves,the calibration model of SPAD value was built by using visible and near infrared(Vis/NIR) spectroscopy technique and chemometrics methods.Different calibration methods were used to build the model in the whole wavelength region.The results indicate that the optimal performance is achieved by least squares support vector machine(LSSVM) model,and the correlation coefficient(r) and root mean squares error of prediction(RMSEP) are 0.9583 and 0.9732,respectively.Via the analysis of correlation coefficients between the spectral reflectance and SPAD values,and the regression coefficients of partial least squares(PLS),two characteristic wavelength bands(531~581nm and 696~716nm) and four characteristic wavelengths(556,581,698 and 715nm) were obtained.LSSVM was used to the aforementioned wavelength bands and wavelengths.The results indicate that the characteristic wavelength bands can achieve a better performance with r of 0.9338 and RMSEP of 1.1370.The prediction results are similar to the whole wavelength region model,while,the performance of LSSVM model with four characteristic wavelengths was not satisfying.Calibration method of using characteristic wavelength bands can largely reduce the calibration computation,and increase the calibration speed.Hence,it is more effective to use characteristic wavelength bands for the detection of SPAD values of cucumber leaves.