激光吸收光谱自适应滤波处理算法研究

Investigation of adaptive filtering algorithm for laser absorption spectroscopy

研究了激光吸收光谱自适应滤波处理算法,提出了一种改进的激光吸收光谱测量系统方案,激光器发射的激光经分束器分成三路,分别构成测量通道、定标通道和参考通道,数据采集电路同步获取三个通道信号数据,定标通道数据用于波长锁定和浓度定标,参考通道信号数据包含了与测量通道相关的噪声,以此为基础构建了自适应噪声抵消器,降低了噪声对测量通道的影响,提高了气体浓度反演的精度。

An adaptive filtering algorithm for laser absorption spectroscopy was investigated. An improved measuring system scheme of laser absorption spectroscopy was proposed. Light beam emitted from laser was divided into three beams which constructed measurement channel, calibration channel and reference channel, respectively. Data acquisition circuit acquired signal data from three channels. Data from calibration channel was used for wavelength locking and concentration calibration. Signal data from reference channel contained noise associated with the measurement channel. Based on this, an adaptive noise canceller was constructed to reduce the effects of noise on measurement channel and improve the accuracy of the gas concentration inversion.