中国激光, 2020, 47 (6): 0611001, 网络出版: 2020-06-03   

基于波长调制光谱和小波去噪的激光甲烷遥测系统 下载: 1173次

Laser Methane Remote Sensor System Based on Wavelength Modulation Spectroscopy and Wavelet Denoising
周言文 1,2苗澍茁 1,2姚丹 1,2董明 1,2郑传涛 1,2,*王一丁 1,2
作者单位
1 吉林大学集成光电子学国家重点联合实验室, 电子科学与工程学院, 吉林 长春 130012
2 吉林省红外气体传感技术工程研究中心, 吉林 长春130012
摘要
为进一步提高激光甲烷遥测仪的抗噪能力,在波长调制光谱技术“相干检测、低1/f噪声”的基础上,进一步利用小波去噪技术的“多尺度、多分辨分析”能力对气体吸收传感信号进行去噪处理。首先建立了一种甲烷遥测系统,通过仿真优化了小波去噪的相关参数,并分析了基于经验模态分解的小波去噪方法的效果;在采用和不采用小波去噪算法的情况下,开展了传感器性能的对比实验,以此验证该技术应用于遥测系统的可行性。利用积分浓度为200×10 -6 m的甲烷气体样品开展的甲烷检测实验结果表明,采用小波去噪算法提取二次谐波信号时,可将信噪比从116.4提高到179.8。对遥测系统开展的标定实验结果表明,提取的二次谐波信号幅值与气体浓度呈正比,未采用小波去噪算法时二者的拟合优度为0.990,采用小波去噪算法后的拟合优度为0.996。根据Allan方差的计算结果,未采用小波去噪算法时检测下限为3.4×10 -6 m,采用小波去噪算法后检测下限降至1.7×10 -6 m,检测分辨率提高了1倍。基于小波去噪和波长调制技术的激光甲烷遥测方法具有较高的信噪比、线性度和稳定性,可推广应用至现有的甲烷遥测系统中。
Abstract
To further improve the anti-noise capability of laser methane remote sensors, on the basis of the property of “coherent detection, low 1/f noise” of wavelength modulation spectroscopy, we further use the ability of “multi-scale, multi-resolution analysis” of wavelet denoising to denoise the absorption signal. Herein, a methane remote sensor system was established, and the relevant parameters of wavelet denoising were optimized through simulations. Moreover, the effects of wavelet denoising based on empirical mode decomposition were discussed. Comparative experiments were conducted to verify the feasibility of the proposed technique in the sensor system for cases where the wavelet denoising algorithm was used and not used. For a methane gas sample with integral concentration level of 200×10 -6 m, measurement results showed that the signal-to-noise ratio was improved from 116.4 to 179.8 using the wavelet denoising algorithm to extract the second harmonic signal. The calibration experiments demonstrated that the amplitude of the extracted second harmonic signal was directly proportional to the gas concentration. For the cases where the wavelet denoising algorithm was not used and used, the goodness of fit was 0.990 and 0.996, respectively. Based on the Allan deviation results, the detection limit was 3.4×10 -6 m without using the wavelet denoising algorithm and 1.7×10 -6m using the wavelet denoising algorithm, with an improvement in detection accuracy by 1 times. The proposed laser methane remote sensing method based on wavelength modulation spectroscopy and wavelet denoising technology exhibited high signal-to-noise ratio, linearity, and stability. The proposed method can be popularized and used in existing methane remote sensor systems.

周言文, 苗澍茁, 姚丹, 董明, 郑传涛, 王一丁. 基于波长调制光谱和小波去噪的激光甲烷遥测系统[J]. 中国激光, 2020, 47(6): 0611001. Zhou Yanwen, Miao Shuzhuo, Yao Dan, Dong Ming, Zheng Chuantao, Wang Yiding. Laser Methane Remote Sensor System Based on Wavelength Modulation Spectroscopy and Wavelet Denoising[J]. Chinese Journal of Lasers, 2020, 47(6): 0611001.

本文已被 10 篇论文引用
被引统计数据来源于中国光学期刊网
引用该论文: TXT   |   EndNote

相关论文

加载中...

关于本站 Cookie 的使用提示

中国光学期刊网使用基于 cookie 的技术来更好地为您提供各项服务,点击此处了解我们的隐私策略。 如您需继续使用本网站,请您授权我们使用本地 cookie 来保存部分信息。
全站搜索
您最值得信赖的光电行业旗舰网络服务平台!