Estimates, Based On The Goal Orientation Of The Vector Hydrophone

A vector hydrophone is composed of two or three spatially co-located but orthogonally oriented velocity hydrophones plus another optional co-located pressure hydrophone.This paper introduces an underwater acoustic eigenstructure ESPRIT-based algorithm that yields closed-form direction-of-arrival (DOA) estimates using a single vector hydrophone. This direction finding algorithm may resolve uncorrelated monochromatic sources, but it assumes that all signal frequencies are distinct. It requires no a priori knowledge of the signals' frequencies, suffers no frequency-DOA ambiguity, and pairs automatically the x-axis direction cosines with the y-axis direction cosines. It significantly outperforms an array of spatially displaced pressure hydrophones of comparable array-manifold size and computational load but may involve more complex hardware. And then, the ESPRIT bearing estimation problem . is reformulated using fourth-order cumulant matrices instead of auto-correlation matrices. By doing so, the fourth-order cumulant matrices of additive colored Gaussian noises can be suppressed. And more aperture extension is achieved in this novel ESPRIT-based two-dimensional angle estimation scheme using a uniform rectangular array of vector hydrophones spaced much farther apart than a half-wavelength. This proposed scheme and the attendant vector-hydrophone array outperform a uniform half-wavelength spaced pressure hydrophone array with the same aperture and slightly greater number of component hydrophones by an order of magnitude in estimation standard deviation.