基于差分吸收光谱法的大气痕量气体在线检测技术

差分光学吸收光谱学技术（Differential Optical Absorption Spectroscopy，DOAS）是近年来发展起来的一种实时检测大气中痕量气体浓度的有效方法，它采用线性最小二乘拟合方法，用痕量气体标准差分吸收截面对测量得到的差分吸收光谱进行拟合，得出大气中痕量气体的浓度。通过介绍DOAS方法的测量原理，在线监测系统的构成，气体浓度的反演方法，测量结果及讨论等内容，说明它在空气质量监测方面的优越性。

On-line monitoring technique for trace gases in atmosphere based on differential optical absorption spectroscopy

Differential optical absorption spectroscopy (DOAS) is a widely used method to measure trace gases in the atmosphere. The concentrations of trace gases can be retrieved by fitting differential absorption spectra with standard differential absorption cross-section using the linear least-square method. The basic principle of DOAS is introduced. The construction of DOAS on-line monitoring system was designed and the retrieval method of trace gases concentration based on the principle of least squares was discussed. The properties of DOAS system were tested by experiments. The advantages of DOAS system used in atmosphere quality monitoring are proven.