Application of Over Sampling ∑-ΔA/D in DOAS System
LI Su-wen1,2, LIU Wen-qing1, XIE Pin-hua1
1. Key Laboratory of Environmental Optical and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China 2. Department of Physics, Huaibei Coal Teachers College, Huaibei 235000, China
Abstract：Differential optical absorption spectroscopy (DOAS) has become a widely used method to measure trace gases in the atmosphere. Concentration of trace gases is retrieved using least-squares fits of reference spectra to the measurement spectra. The measurement precision not only depends on the measurement precision of spectra and the noise of instrument and disturbing of other gases in measuring band, but suffers the influence of signal sampling and pre-processing. The present paper simply introduced DOAS measuring principle and the setup of instrument and put forward improving method-the technology of over sampling ∑-ΔA/D. Using the ∑-Δ modulator structure to shape noises together with the over sampling technology can doubly restrain quantifying noises, which can improve the signal-to-noise ratio within the measuring band. So the measurement precision of DOAS system is improved with this technology.
Key words：∑-ΔA/D;DOAS;Analysis of errors;Signal-to-noise ratio
李素文1, 2,刘文清1,谢品华1 . 过采样∑-ΔA/D技术在差分吸收光谱系统中的应用[J]. 光谱学与光谱分析, 2006, 26(12): 2291-2293.
LI Su-wen1,2, LIU Wen-qing1, XIE Pin-hua1 . Application of Over Sampling ∑-ΔA/D in DOAS System. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2006, 26(12): 2291-2293.
