Imaging Science and Photochemistry ›› 2014, Vol. 32 ›› Issue (2): 191-199.DOI: 10.7517/j.issn.1674-0475.2014.02.191

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Application of Wavelet De-noising Method in Concentration Measuring System Based on DOAS

MEI Weipeng1, YU Miao1, SHI Xiang1, WANG Ying1, FU Jie1, ZHANG Yongcai2   

  1. 1. Research Center of Sensing and Instrumentation Technologies, Chongqing University, Chongqing 400044, P.R.China;
    2. LongYuan Combustion Control Engineering Co., Ltd., Yantai Development Zone, Yantai 264006, Shandong, P.R.China
  • Received:2013-08-27 Revised:2013-12-02 Online:2014-03-15 Published:2014-03-15

Abstract:

The concentration measuring system based on DOAS is developed to watch the concentration of the sulfur dioxide in pollution gases. In order to decrease the influence of the system noise and the Mie Scattering,the wavelet de-noising method is used. By comparing 4 kinds of different wavelet function and improving traditional threshold value, the de-noising method based on rigisure threshold is found, and a new measurement is put forward to measure the effects of signal processing. This kind of technology is applied to processing the spectral signal accurately and reliably, and the error is controlled under 1.5%. Experimental research results and industry scene results show that the wavelet de-noising method can greatly improve the SNR of the system and minimize bad effects of noises.

Key words: wavelet, wavelet de-noising, threshold value, DOAS, concentration measuring of sulfur dioxide