基于频谱校正的傅里叶变换滤波差分吸收光谱监测实验研究

DOAS Monitoring by Fourier Transform Filtering Based on Frequency Spectrum Correction

在差分吸收光谱(DOAS)傅里叶变换(FFT)滤波数据处理中引入频谱校正,针对单组分SO2和NO2气体进行了实验研究,并进行了模拟谱线漂移的实验.结果表明:对于单组分SO2和NO2气体,传统的最小二乘法与校正FFT滤波法均能取得不错的效果,误差在5%以下,但校正FFT滤波法较FFT滤波法的效果更好;在漂移2个波长时校正FFT滤波法的最大误差为3.65%,传统最小二乘法的平均误差为32.80%,前者效果明显优于后者.

Frequency spectrum correction was introduced to the data processing based on differential optical absorption spectroscopy(DOAS)by fast Fourier transform(FFT)filtering,while experimental studies were conducted to single-component gases SO2 and NO2 by simulation of spectral line drift.Results show that for single-component gases SO2 and NO2,both the traditional least square method and the corrected FFT filtering can achieve good effects,with an error less than 5%;however,the corrected FFT method has better effect than the uncorrected one;for a drift of two wavelengths,the maximum error of corrected FFT method is 3.65%,and the mean error of traditional least square method is 32.80%,indicating that the former has significantly better effect than the latter.