Comparison and application of wavelet transform and Kalman filtering for denoising in δ¹³CO₂ measurement by tunable diode laser absorption spectroscopy at 2.008 µm

We propose to use the wavelet transform and Kalman filter methods for processing noise in δ¹³CO₂ measurement using laser absorption spectroscopy at 2.008 µm and they have been shown to be useful tool for reducing the intrinsic noise of the optical system. Through the performance comparison and analysis of these two denoising techniques for the intrinsic noise reduction of optical system, it can be found that the Kalman filter is a more suitable approach for the extraction of gas isotope measurement signal from a contaminated signal.