Time-space transform: A novel signal processing approach for an acoustic vector-sensor

A new signal processing method using a single vector hydrophone is proposed for solving the problem of azimuth angle estimation for multiple targets based on a small aperture underwater platform. The method extends the aperture from a single vector hydrophone into a half wavelength distance uniform linear array by decomposing the time-domain sample data from different channels of the hydrophone. The extended array has a narrower space beam pattern than a single vector hydrophone. The azimuths of spatial multiple targets are estimated by using the appended array snapshots under the condition of broadband or narrow band signals. The new method is robust because there is no need to correct the array manifold. Theoretical analysis and computer simulations show that, the new algorithm has the ability to distinguish two incoherent targets with either narrow band or broadband signals in an isotropic noise field. The algorithm provides a non-biased estimate with a high signal-to-noise ratio.