CAJ | 학술논문

差分吸收光谱法（differential optical absorption spectroscopy ，DOAS）是一种常用的污染气体监测方法，对所监测的光谱数据去噪可以提高反演精度。可采用傅里叶变换（fast Fourier transform ，FFT ）滤波法滤除光谱数据中的噪声，但该算法本身会引入误差。提出一种线性调频Z变换法（chirp Z transform ，CZT ），通过对傅里叶变换之后的频谱进行局部细化，能够在保留傅里叶变换滤波法去噪效果的基础上，对算法的误差进行补偿，从而进一步提高反演精度。实验配置了SO2及NO2进行浓度反演，结果表明，直接采用相除法反演浓度时误差较大且很不稳定，线性调频Z变换法能够获得比傅里叶变换滤波法更高的反演精度。模拟了SO2和NO2混合气体实验，频谱分析结果表明FFT 算法无法解决特征吸收结构被扭曲、削弱等问题，CZ T算法能完成特定频段频谱的精细化重构。
차분흡수광보법（differential optical absorption spectroscopy ，DOAS）시일충상용적오염기체감측방법，대소감측적광보수거거조가이제고반연정도。가채용부리협변환（fast Fourier transform ，FFT ）려파법려제광보수거중적조성，단해산법본신회인입오차。제출일충선성조빈Z변환법（chirp Z transform ，CZT ），통과대부리협변환지후적빈보진행국부세화，능구재보류부리협변환려파법거조효과적기출상，대산법적오차진행보상，종이진일보제고반연정도。실험배치료SO2급NO2진행농도반연，결과표명，직접채용상제법반연농도시오차교대차흔불은정，선성조빈Z변환법능구획득비부리협변환려파법경고적반연정도。모의료SO2화NO2혼합기체실험，빈보분석결과표명FFT 산법무법해결특정흡수결구피뉴곡、삭약등문제，CZ T산법능완성특정빈단빈보적정세화중구。
Differential optical absorption spectroscopy (DOAS ) is a commonly used atmospheric pollution monitoring method . Denoising of monitoring spectral data will improve the inversion accuracy .Fourier transform filtering method is effectively capa‐ble of filtering out the noise in the spectral data .But the algorithm itself can introduce errors .In this paper ,a chirp‐z transform method is put forward .By means of the local thinning of Fourier transform spectrum ,it can retain the denoising effect of Fourier transform and compensate the error of the algorithm ,which will further improve the inversion accuracy .The paper study on the concentration retrieving of SO2 and NO2 .The results show that simple division causes bigger error and is not very stable .Chirp‐z transform is proved to be more accurate than Fourier transform .Results of the frequency spectrum analysis show that Fourier transform cannot solve the distortion and weakening problems of characteristic absorption spectrum .Chirp‐z transform shows ability in fine refactoring of specific frequency spectrum .