Acoustic Signature Modelling of Marine Vessels in Various Environmental and Operational Conditions

Acoustic noise generated by a marine vessel depends on the ship type, speed, and operational conditions. A combination of these parameters extracted during the analysis process is known as an acoustic signature, which plays an important role in their automatic classification. The high cost of data gathering, dynamic conditions of the propagating medium, and unknown operational conditions of the vessel make it impractical to cover a complete realization of the vessel signature. This study suggests an alternative method to mathematically model onboard machinery, propeller, and hydrodynamic flow noise of multiple classes of vessels under different operational conditions. In this paper time-varying Bellhop propagation models for shallow & deep ocean channel, constant sound velocity profile, and target ranges are modeled. The impulse response of the channel is convoluted with the acoustic signatures of the vessel. Finally, various simulated sea state noises can be added to mimic realistic signal-to-noise ratios (SNR). The resultant received acoustic signature is analyzed using LOFAR gram and is significantly affected by internal and external parameters.