城市空气质量监测系统(DOAS)谱线漂移问题及解决方法  

A Method for Resolving Spectra Shift in the Urban Air Quality Monitoring System(DOAS)

作　　者：刘世胜[1] 魏庆农[1] 冯巍巍[1] 詹锴[1] 王锋平[1] 

机构地区：[1]中国科学院环境光学与技术重点实验室,中国科学院安徽光学精密机械研究所,安徽合肥230031

出　　处：《光谱学与光谱分析》2009年第6期1450-1453,共4页Spectroscopy and Spectral Analysis

基　　金：国家“863”资源环境技术领域项目(2002AA641020)资助

摘　　要：城市空气质量监测系统中差分光学吸收光谱法的光学部分受到外界影响(温度、光纤位置等),或是氙灯自身的变化,都会引起测量谱线的漂移。如果灯信号谱与大气测量信号谱谱线漂移不一致而产生谱线相对偏移,将直接影响测量结果的准确性。因此,在运用DOAS方法进行大气痕量气体污染物浓度反演时,必须对大气测量信号谱和灯信号谱进行波长匹配。文章通过对氙灯自身发射光谱特殊结构的研究,提出了利用氙灯特征发射峰,通过对两个信号光谱进行最小二乘拟合,达到谱线校正的方法。实验结果证明,这种方法可以有效地减小谱线相对偏移对大气痕量气体污染物浓度反演结果的影响。In the urban air quality monitoring system, there is spectra shift which is caused by environment factors on the optical part （temperature and optic fiber position）, or by the self-change of Xe-lamp. Relative spectra shift will occur if the shift of lamp-spectrum and air-spectrum is inconsistent which has direct influences on the accuracy of the measurement results. So the match of wavelength between lamp-spectrum and air-spectrum should be considered when we retrieve pollutants concentration t of trace gas in the atmosphere through DOAS method. Based on the study of the unique structures for Xe-lamp emitting spectrum, a method for the calibration of two signal spectra using Xe-lamp emitting peak and least square fitting is given. The results show that, the impact of spectrum shift can be reduced by this method for retrieving results.

关 键 词：差分光学吸收光谱 谱线相对偏移 谱线校正 

分 类 号：O433.5[机械工程—光学工程]