ACOUSTIC CAMERA SHIP NOISE MEASUREMENTS DURING DOCKING OPERATIONS: A CASE STUDY IN GENOA

Port noise is characterized by the overlapping of multiple sources, of which ships represent one of the most relevant. The study of the noise emission from ships is a difficult task due to the dimensions of the ships and the simultaneous emission from different onboard sources. The noise coming from the port causes discomfort and complaints, particularly in ports which are surrounded by hills with residential buildings, such as the port of Genoa. This work aims to characterize the emission of a ship during docking in the port of Genoa using an acoustic camera. Acoustical images and videos of the arrival and of the docking manoeuvres of Ro-Pax vessels were obtained from different positions using an acoustic camera suitable for outdoor long-range measurements. Acoustical maps obtained from the measurements are used to characterize the spatial distribution of the noise and to detect the location and level of the main sources. Results from the overall sound pressure levels were compared with standard sound level meter measurements. In this way, some sources were precisely located in the ships, mainly on the ventilation system and engine exhaust. This approach confirms that acoustic camera measurements are useful for obtaining relevant empirical information that can be used to model the port noise and to propose possible mitigation strategies, overcoming the limitations of traditional techniques based on sound level meters measurements.