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