Applications of wavelet transform to quantum cascade laser spectrometer for atmospheric trace gas measurements
Applications of wavelet transform to quantum cascade laser spectrometer for atmospheric trace gas measurements
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DOI：
10.1007/s00340-012-5158-7
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发表时间：
2012-09-01
影响因子：
2.1
通讯作者：
Fischer, Horst
中科院分区：
文献类型：
--
作者：
Li, Jingsong;Parchatka, Uwe;Fischer, Horst
基于小波变换的数字滤波器在量子级联激光光谱中的应用通过其应用于模拟光谱和使用我们新颖紧凑的QCL光谱仪获得的实验结果进行了研究，这为在高时间分辨率（小于1秒）下对大气中感兴趣的物种的痕量气体浓度进行高灵敏度和选择性测量提供了潜力。通过在信号后处理中应用小波数字滤波，在不降低快速时间响应的情况下，实现了更好的测量精度和更高的检测灵敏度。详细介绍了应用于光谱数据的小波变换理论。为了进行比较，还测试了其他常用滤波技术（即卡尔曼滤波器、维纳滤波器和移动平均）的结果。最后，实验结果表明，无论是对于光谱信号处理还是痕量气体浓度信号评估，基于小波的滤波器似乎都是降噪的最佳选择。
The application of wavelet transform-based digital filter to quantum cascade laser spectroscopy was investigated by its application to simulated spectra and experimental results obtained with our novel and compact QCL spectrometer, which offers the potential for high sensitive and selective measurements of trace gas concentration at high temporal resolution (less than 1 s) for species of interest in the atmosphere. With the application of wavelet digital filtering in post-signal processing, better measurement precision and higher detection sensitivity have been achieved, without reducing the fast temporal response. Details of wavelet transform theory applied to the spectroscopic data are presented. For comparison, the results of other commonly used filter techniques (i.e. Kalman filter, Wiener filter and moving average) are also tested. Finally, the experimental results show that the wavelet-based filter seems to be the superior choice for noise reduction, both for spectral signal processing and trace gas concentration signal evaluation.