Blind deconvolution of shipping sources in an ocean waveguide.

This paper investigates the applicability of a ray-based blind deconvolution (RBD) method for underwater acoustic sources of opportunity such as ships recorded on a receiver array. The RBD relies on first estimating the unknown phase of the random source by beamforming along a well-resolved ray path, and then matched-filtering each received signal using the knowledge of this random phase to estimate the full channel impulse responses (CIRs) between the unknown source and the array elements (up to an arbitrary time-shift) as well as recovering the radiated signal by the random source. The performance of this RBD is investigated using both numerical simulation and experimental recordings of shipping noise in the frequency band [300-800 Hz] for ranges up to several kilometers. The ray amplitudes of the estimated CIRs are shown to be consistent with known bottom properties in the area. Furthermore, CIRs obtained for an arbitrarily selected shipping track are used as data-derived replicas to perform broadband matched-field processing to locate another shipping source recorded at a later time in the vicinity of the selected track.