[1] Li J Y, Yu Z W, Du Z H et al. Standoff chemical detection using laser absorption spectroscopy: a review[J]. Remote Sensing, 12, 2771(2020).

[2] Liu C, Xu L J. Laser absorption spectroscopy for combustion diagnosis in reactive flows: a review[J]. Applied Spectroscopy Reviews, 54, 1-44(2019).

[3] Du Z H, Zhang S, Li J Y et al. Mid-infrared tunable laser-based broadband fingerprint absorption spectroscopy for trace gas sensing: a review[J]. Applied Sciences, 9, 338(2019).

[4] Li J S, Yu B L, Zhao W X et al. A review of signal enhancement and noise reduction techniques for tunable diode laser absorption spectroscopy[J]. Applied Spectroscopy Reviews, 49, 666-691(2014).

[5] Li J Y, Luo G, Du Z H et al. Hollow waveguide enhanced dimethyl sulfide sensor based on a 3.3 μm interband cascade laser[J]. Sensors and Actuators B, 255, 3550-3557(2018).

[6] Xiong B, Du Z H, Li J Y. Modulation index optimization for optical fringe suppression in wavelength modulation spectroscopy[J]. The Review of Scientific Instruments, 86, 113104(2015).

[7] Werle P, Slemr F. Signal-to-noise ratio analysis in laser absorption spectrometers using optical multipass cells[J]. Applied Optics, 30, 430-434(1991).

[8] Liang Y, Liu T G, Liu K et al. Optimized gas detection method based on variational mode-decomposition algorithm[J]. Chinese Journal of Lasers, 48, 0706003(2021).

[9] Zhang T Y, Kang J W, Meng D Z et al. Mathematical methods and algorithms for improving near-infrared tunable diode-laser absorption spectroscopy[J]. Sensors, 18, 4295(2018).

[10] Zheng C T, Ye W L, Huang J Q et al. Performance improvement of a near-infrared CH4 detection device using wavelet-denoising-assisted wavelength modulation technique[J]. Sensors and Actuators B, 190, 249-258(2014).

[11] Yao D, Zheng K Y, Liu Z D et al. Wavelet denoising in near-infrared broadband cavity-enhanced absorption spectroscopy[J]. Acta Optica Sinica, 39, 0930006(2019).

[12] Bai W Y, Xue W C, Huang Y et al. The extended state filter for a class of multi-input multi-output nonlinear uncertain hybrid systems[C], 2608-2613(2014).

[13] Zhou S, Liu N W, Shen C Y et al. An adaptive Kalman filtering algorithm based on back-propagation (BP) neural network applied for simultaneously detection of exhaled CO and N2O[J]. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 223, 117332(2019).

[14] Leleux D P, Claps R, Chen W et al. Applications of Kalman filtering to real-time trace gas concentration measurements[J]. Applied Physics B, 74, 85-93(2002).

[15] Sun M G, Ma H L, Liu Q et al. Real-time and on-line measurement system for trace gas with active control parameters[J]. Acta Optica Sinica, 38, 0530003(2018).

[16] Zheng F, Qiu X B, Shao L G et al. Measurement of nitric oxide from cigarette burning using TDLAS based on quantum cascade laser[J]. Optics & Laser Technology, 124, 105963(2020).

[17] Niu M S, Han P G, Song L K et al. Comparison and application of wavelet transform and Kalman filtering for denoising in δ13CO2 measurement by tunable diode laser absorption spectroscopy at 2.008 µm[J]. Optics Express, 25, A896-A905(2017).

[18] Chen J J. Trace gases and isotopes measurements based on long-path length laser absorption spectroscopy[D](2018).

[19] Xia J B, Feng C, Zhu F et al. Real-time measurement of methane in a turbulent atmosphere over kilometer long paths with denoising methods[J]. Measurement, 168, 108467(2021).

[20] Bai W Y, Xue W C, Huang Y et al. Extended state filter design for general nonlinear uncertain systems[C], 712-717(2015).

[21] Li J Y, Zhang C G, Wei Y Y et al. In situ, portable and robust laser sensor for simultaneous measurement of ammonia, water vapor and temperature in denitrification processes of coal fired power plants[J]. Sensors and Actuators B, 305, 127533(2020).