Sparse time delay estimation and source ranging in sound shadow zone of deep water

The correlation between the time delays of multipath rays reflected once by the bottom arriving at vertical dual hydrophones and the source location in the sound shadow zone of deep water is studied.A sparse time delay estimation and source ranging method is proposed.The acoustic signals in a certain frequency band are first received by a pair of short spaced hydrophones deployed vertically near the surface.The generalized cross-correlation function of the received signals is then calculated.The time delays are then extracted using spectrum shifting and sparse deconvolution.The range of the submerged source is finally estimated using time delay matching.The simulations show that the proposed method can correctly extract the time delays of multipath arrivals and estimate the source range within the sound shadow zone in deep water of 4300 m depth.The sea experiments show that the source ranging error is less than 13.6% and 8.1% when the vertical receiving aperture is 21 m and 30 m,respectively.The above results prove that the proposed time delay estimation method can be used for signals with narrow bandwidth in deep water.And the estimated time delay parameters can be used for submerged source ranging in the sound shadow zone.