Extraction of low frequency line spectrum of ship radiated noise based on the 1 1/2D spectrum

Special properties of a 1 1/2D spectrum were analyzed. By means of these properties, the Gaussian noise and symmetrically distributed noise can be restrained. The fundamental frequency component of the harmonic signals can be enhanced and non-quadratic phase coupling harmonic components can be eliminated. By calculating the 1 1/2D spectrum of actual ship radiated noise, fine results in classification and identification were achieved. This will be helpful in the research of detecting and identifying underwater objects.