An Automatic Baseline Extraction Algorithm for Intensity Absorption Type Gas Sensing

A novel algorithm for automatic baseline extraction of gas absorption spectrum is proposed. It is based on an automatic signal-free regions recognition that uses a difference of Gaussians function, followed by a baseline fitting procedure based on segmented polynomial fitting and segmented kernel smoothing. This algorithm has been applied to both simulated data and experimental data. The results show that this algorithm can extract baseline of spectrum with a wide range of possible baseline types, is tolerant to low signal-to-noise ratio spectrum, and to signals of varying widths in a single spectrum. Moreover, the efficiency of the algorithm is tested by accurately detecting the absorbance of experimental CO 2 absorption spectrum and C 2H 2 absorption spectrum.