Feature extraction of underwater target based on the time-frequency analysis

Target feature extraction is a prerequisite for the target recognition. This paper mainly researched on extracting the features of underwater targets based on the time-frequency analysis. The method of time-frequency analysis-S transform was introduced and applied in underwater signal processing. The single-frequency signal, pulse signal and two kinds of ship-radiated noises collected by hydrophone were processed by S transform. According to the time-frequency distribution, the phase information and the instantaneous-frequency estimation of signals were studied. Then singular value based on S transform was proposed as another feature of ships. The results proved that the features of underwater targets can be extracted effectively by S transform.