基于波长选择的纸页厚度太赫兹时域光谱检测新方法

光谱数据的波长选择是太赫兹光谱定量分析的关键。以纸页厚度检测为例，提出了一种基于波长选择的纸页厚度太赫兹相位谱检测新方法。首先采用离散离子群算法进行太赫兹相位信号优选，并应用偏最小二乘法建立纸页厚度定量模型，以模型的预测均方根误差作为太赫兹相位信号优选的评价标准，选择出预测效果最优的太赫兹相位信号，进行纸页厚度预测。最后将本文方法的预测结果与采用全谱和单频相位信号的预测结果进行比较，结果表明，提出的方法预测结果最好。

Wavelength Selective Terahertz Time-Domain Spectroscopy for Paper Thickness Measurement

Wavelength selection of spectra plays an important role in the quantitative analysis of terahertz spectroscopy. In this paper, a new method for quantitative measurement of paper sheet thickness is presented based on wavelength selection of terahertz phase spectra. Besides, binary particle swarm optimization (BPSO) algorithm is applied in wavelength selection of terahertz phase spectra and partial least square (PLS) algorithm is employed to establish the quantitative analysis model of paper sheet thickness. In addition, the root mean square error of prediction (RMSEP) is analyzed to show the performance of the method. Finally, the prediction error of the method is compared with both the methods using the raw spectra and the method using a single wavelength of the spectra. The results show that the method of this paper gives the most satisfactory quantitative accuracy.