Effects of reference sound speed on underwater acoustic direction-of-arrival estimation with horizontal plane array.

Abstract

Direction-of-arrival (DOA) estimation of an underwater acoustic target is usually dependent on the selection of reference sound speed. For a horizontal line array, severe error of DOA estimation is induced when reference sound speed diverges from phase velocity. For a horizontal plane array, this work investigates the effects of reference sound speed on DOA estimation based on normal-mode theory, finding an independence between estimated azimuth and reference sound speed. Simulated and experimental results demonstrate that azimuth can be unbiasedly estimated and is irrelevant to reference sound speed below an upper bound in environments with various sound speed profiles.