Localization of underwater tone noise sources by a small aperture circular array

Based on the joint information of space-time-frequency, a novel scheme is proposed for localizing the low-frequency tone noise sources of an underwater moving vehicle by using a small aperture circular array. First, the Doppler signals formed when the noise sources pass through the closest point of approach (CPA), are separated in time domain with superdirectivity beamforming. Thereafter, processing the LFM signals output from the narrow beam by pseudo Wigner-Ville distribution, the CPA times of the tone noise sources are estimated from time-frequency images of the noise signals. Finally, conversing time coordinate to space and using a reference source, the position of each low-frequency tone noise source on the underwater vehicle is identified. This scheme can be applied to the coherent acoustic sources. Simulation results validated the proposed scheme.