[1] [1] Ye W, Tu Z, Xiao X, et al. A NDIR mid- infrared methane sensor with a compact penta- hedron gas-cell[J]. Sensors, 2020, 20(19): 5461.

[5] [5] F. X. Xin, J. Li, J. J. Guo, et al., “Measurement of atmospheric CO2 column concentrations based on open-path TDLAS,”[J]. Sensors, 2021, 21: 1722.

[6] [6] Li C, Dong L, Zheng C, et al. Compact TDLAS based optical sensor for ppb-level etha- ne detection by use of a 3.34 m room-temp- erature CW interband cascade laser[J]. Sensors Actuators: B. Chemical, 2016, 232: 188-194.

[13] [13] Yang R, Bi Y, Zhou Q, et al. A background reduction method based on empirical mode dec- omposition for tunable diode laser absorption spectroscopy system[J]. Optik, 2018, 158.

[16] [16] Donoho D L, Johnstone I, Montanari A. Accurate prediction of phase transitions in compressed sensing via a connection to minim- ax denoising[J]. IEEE Transactions on Information Theory, 2013, 59(6): 3396.