大气与环境光学学报, 2011, 6 (2): 95, 网络出版: 2011-03-28
基于可调谐半导体激光吸收光谱的大气水汽检测方法研究
Atmospheric Water Vapor Concentration Measurement Method Based on Tunable Diode Laser Absorption Spectroscopy
大气水汽 直接吸收光谱 吸光度 非线性最小二乘算法 atmospheric water vapor direct-absorption spectroscopy absorbance non-linear least-squares method
摘要
用激光吸收光谱方法对大气水汽浓度检测进行了研究。采用窄线宽的半导体激光器作光源,通过直接吸收 光谱技术来反演气体浓度。低阶多项式对直接吸收信号进行基线拟合以消除光强波动获得吸光度曲线,再 用非线性拟合Levenberg-Marquardt算法进行线型拟合获取积分吸光度,从而根据HITRAN数据库中或实验 室测定的吸收线强和展宽系数等参数来进行水汽浓度的直接反演。选取了1.4 μm附近的两条水汽吸收线进 行了浓度检测验证和分析。
Abstract
A water vapor concentration measurement method was studied based on direct absorption spectroscopy techniques. Using DFB diode laser as light source, the concentration of water vapor is obtained through the integrated absorbance inversion. First a low-order polynomial baseline fitting was carried out on sub-regions of the transmitted signal to eliminate the effect of diode-laser output power fluctuation and the absorbance curve was obtained. Then integrated absorbance can be inverted through line-shape fitting using Levenberg-Marquardt non-linear least-squares fitting method. Two absorption lines for concentration measurement near 1.4 μm of water vapor were selected to verify the method.
许振宇, 刘文清, 阚瑞峰, 张玉钧, 张帅, 束小文, 何莹, 张亮, 汤媛媛. 基于可调谐半导体激光吸收光谱的大气水汽检测方法研究[J]. 大气与环境光学学报, 2011, 6(2): 95. XU Zhen-yu, LIU Wen-qing, KAN Rui-feng, ZHANG Yu-jun, ZHANG Shuai, SHU Xiao-wen, HE Ying, ZHANG Liang, TANG Yuan-yuan. Atmospheric Water Vapor Concentration Measurement Method Based on Tunable Diode Laser Absorption Spectroscopy[J]. Journal of Atmospheric and Environmental Optics, 2011, 6(2): 95.
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