Bearing estimation with acoustic vector‐sensor arrays

We consider direction‐of‐arrival (DOA) estimation using arrays of acoustic vector sensors in free space, and derive expressions for the Cramer‐Rao bound on the DOA parameters when there is a single source. The vector‐sensor array is seen to have improved performance over the traditional scalar‐sensor (pressure‐sensor) array for two distinct reasons: its elements have an inherent directional sensitivity and the array makes a greater number of measurements. The improvement is greatest for small array apertures and low signal‐to‐noise ratios. Examination of the conventional beamforming and Capon DOA estimators shows that vector‐sensor arrays can completely resolve the bearing, even with a linear array, and can remove the ambiguities associated with spatial undersampling. We also propose and analyze a diversely‐oriented array of velocity sensors that possesses some of the advantages of the vector‐sensor array without the increase in hardware and computation. In addition, in certain scenarios it can avoid prob...