Passive wideband source localization based on cylindrical focused beamforming in shallow water

This paper addresses the problem of passive wideband localization of a shallow water noise source in near-field with a horizontal array in the presence of multipath propagation. Multipath propagation gives rise to attenuated and time-delayed replicas of the original transmitted signal. The conventional beamforming approach to wideband localization involves the coherent signal-subspace method (CSM) via the transformation of signal subspace. In shallow water scenarios, multipath effect yields source localization bias using the conventional beamforming approach, source resolution accuracy degrades owing to the higher side lobe contributions to the beamformer output. In this paper, the steering vector is constructed in accordance with the characteristic of shallow water acoustic channel based on passive time reversal method. Cylindrical focused beamforming is used according to the shape of acoustic radiant surface. Simulation results demonstrate that source localization performance of conventional beamforming approach is improved significantly in multipath environment.