A method of reference phase velocity selecting for bearing estimation with a horizontal line array in shallow water

In shallow water environments, choosing an appropriate reference phase velocity for direction-of-arrival estimation with a beamformed underwater horizontal line array is very important. The direction of the maximum beamformer output power will deviate from the true source bearing when a mismatched reference phase velocity was used. This Letter analyzed the intrinsic relationship between the reference phase velocity and normal mode amplitude distribution, source bearing, array aperture, and then proposed a multi-parameter weighted reference phase velocity selection method, which has improved the accuracy of source bearing estimation. Numerical simulation and experimental results validated the effectiveness of this method.