Extracting vibrational parameters from the time-frequency map of a self mixing signal: An approach based on wavelet analysis

The characterization of the time-frequency map that is obtained from wavelet analysis allows us to view the temporal and spectral components of non-stationary signals simultaneously. Wavelets thus provide a complete platform from where the parameters of interest in the signal in time and/or frequency domain can be extracted. In this paper, we analyse the conventional self mixing interferometry signal (SMS) in the time-frequency domain by using wavelet analysis, in order to extract vibrational features of the target directly from the SMS, to detect the moment in time when the direction of the target changes, the velocity of the target or its displacement.