Broadband passive synthetic aperture: Experimental results

Bearing estimation using an acoustically short towed array can be enhanced by the incorporation of a realistic signal model. By casting the problem as a joint estimation of bearing and source frequency, the bearing estimation performance, as measured by the variance of the bearing estimate, can exceed that of the conventional array processor. Experimental results based on the radiated noise of a ferry are shown. Bearing estimation results using an array of acoustic length of approximately two wavelengths are compared to results using the same data but with a conventional frequency domain beamformer. A significant improvement in performance is demonstrated.