Measurements of ship noise using an acoustic camera: A preliminary survey

As the acoustic impact of harbors becomes an increasingly pressing issue, even limiting their growth, the measurement of noise from ships and port operations remains underdeveloped. Two primary challenges are commonly encountered: source overlapping and the significant distance from the emitting sources. Source overlapping complicates the identification of the specific contributions of individual noise sources. Additionally, the large distance from sources—such as a ship's funnel or the engine of a transtainer crane—can compromise measurement accuracy. The use of an acoustic camera effectively addresses both challenges simultaneously. This technology allows noise measurements to be performed at a distance from the source while isolating the contributions of individual emitters within the sound field. This paper demonstrates the capabilities of the acoustic camera through a series of surveys conducted in French and Italian ports. Ship noise emissions were analyzed in various operational scenarios, including ships underway, maneuvering within harbors, and berthed at wharves. The effectiveness of the beamforming technique is evaluated, focusing on measurement accuracy, its qualitative and quantitative significance, and the feasibility of establishing standardized measurement protocols for ships based on this methodology.