Application of VMD and Mahalanobis distance combination algorithm in TDLAS methane gas detection

A novel variational mode decomposition and Mahalanobis distance combination algorithm is proposed. The proposed algorithm is used in the traditional tunable diode laser absorption spectroscopy. The equation and detection procedure of the algorithm are presented to handle spectral signals affected by noise, which lead to inversion concentration with small deviation. The simulation and experiment verify that the algorithm is effective. Experiments show that the maximum detection error is minimized from 10.43 % to 7.34 % over a concentration range of 8–99 ppm.