Wavelet analysis on ship radiated noise

Wavelet Transform's multi-resolution characteristics is applied to the analysis of ship radiated noise.In contrast to the fixed resolution in time frequency plane of Short-Time Fourier Transform,Wavelet Transform has arbitrary good time resolution at high frequencies and good frequency resolution at low frequencies.It is showed that Wavelet Transform plays a good role in the time-frequency analysis of the ship-radiated noise.The energy distribution at low frequency band and propeller's modulation to the noise at the whole band can be displayed in one Scalogram,but STFT cannot.When describing and displaying the ship noise's spectrum characteristics,we separate it into two parts of stationary and nonstationary respectively.This separation is based on its local stationary property and it has a good effect in our experiment.