基于近红外光谱技术的马铃薯叶片含水率高效预测

提出了运用近红外光谱技术检测新鲜马铃薯叶片中含水量的方法，并通过预测结果和运算量的对比得出一种高效率的预测方法。采集了900～2100 nm波段范围内110个新鲜马铃薯叶片的光谱反射率信息，经SG（Savitzky-Golay）平滑、多元散射校正（MSC）和标准正态变量变换（SNV）3种预处理后，分别建立偏最小二乘回归（PLSR）模型和BP神经网络模型，再运用回归系数（regression coefficients, RC）法在全波段光谱中提取特征波长，同样经3种预处理后分别建立预测模型。结果表明：在运用光谱全波段信息构建的模型中，经多元散射校正（MSC）预处理建立的BP神经网络模型预测效果最好，预测集决定系数R²为0.9791，均方根误差RMSE为0.3723；在基于特征波长构建的模型中，经SG平滑预处理建立的神经网络模型预测效果最优，预测集决定系数R²为0.9658，均方根误差RMSE为0.4759；验证了特征波段结合BP神经网络建立的模型与全波段建立的模型预测结果相差不大，因而能够极大地减少运算量，提高预测效率。

Efficient determination of water content in potato leaves based on spectroscopy technology

The determination of moisture content in potato leaves using spectral technique was studied in this paper. Spectral signatures of one hundred and ten fresh potato leaves in the wavelengths of 900-2100 nm were acquired by the spectral device. Then, the moisture content was measured by the drying method.The near-infrared reflection spectrum information was corrected by the Savitzky-Golay (SG) smoothing, multiplicative scatter correction (MSC) and standard normal variable (SNV) correction. The quantitative relationship between spectral information and moisture was built by partial least squares regression (PLSR) and BP neural network respectively. The effective wavelength was identified by regression coefficients (RC) and corrected by three pretreatment methods. Then the PLSR and BP neural network models were built respectively. The results showed that for full wavelengths-based models, MSC-BP model performed the best with the coefficient of determination (R²) of 0.9791 and the root mean square error (RMSE) of 0.3723 in the prediction. For selected wavelengths-based models, it was the SG-BP model that obtained the optimal result. The R² value was 0.965 8 and the RMSE value was 0.475 9 in the prediction. This experiment verified that the prediction results of the model established by combining the characteristic band with BP neural network were not different from those of the model established by the whole band, so it could greatly reduce the computation and improve the efficiency.