Vibration of the vessel and bispectrum of hydroacoustic noise

The origin of vessels vibrations is dominantly determined by vessels propulsion system, auxiliary systems, pumps, breaking of the waves at the ship hull, etc. All of these systems contribute to the appearance of the underwater sound in water environment. As a source of underwater sound, vessels has the characteristic of directivity. Vibration of the vessel's structure is analyzed using spectra, but hydroacoustic signals are analyzed using spectra and higher order spectral analysis - bispectra. The measuring of the radiated hydroacoustic noise was done simultaneously with multi channel measurements of the vessels vibrations at few characteristics positions of the vessel.