Closed-form underwater acoustic direction-finding with arbitrarily spaced vector-hydrophones at unknown locations

This paper introduces a novel ESPRIT-based, closed-form source localization algorithm applicable to arbitrarily spaced three-dimensional arrays of vector-hydrophones, whose location need not be known. Each vector-hydrophone consists of two or three identical but orthogonally oriented velocity-hydrophones plus one pressure-hydrophone, all spatially co-located in a point-like geometry. A velocity-hydrophone measures one Cartesian component of the incident sonar wavefield's velocity-vector, whereas a pressure-hydrophone measures the acoustic wavefield's pressure. Velocity-hydrophone technology is well established in underwater acoustics and a great variety of commercial models have long been available. ESPRIT is realized herein by exploiting the non-spatial inter-relation among each vector-hydrophone's constituent components, such that ESPRTT's eigenvalues become independent of array geometry. Simulation results verify the efficacy and versatility of this innovative scheme. Aspects of this sonar algorithm is analogous to Jian Li's earlier work (1993) with diversely polarized antennas.