DCN Ingenierie Sud, Dept. LSM, B.P. 30, 83800 Toulon Naval, France
The performances of acoustic arrays for passive sonar systems are limited by ambient noise and by self-noise phenomena, such as turbulent flow-induced noise, machinery noise propagating along the hull, or propellor noise. To predict the performances of the system and to improve the design of the arrays, it is important to determine which self-noise component is dominant on a given ship at different speeds. This paper will present the behavior of the typical coherence functions between the hydrophones of a flank array, for the different noise components. As the evolution along sensor separation and/or frequency for each component is characteristic, the analysis of the coherence in a real experiment can be used to determine the dominant contribution. An example on a submarine will be given.