Localization algorithm and error analysis for surface targets based on a 2D planar array in deep-sea environment

To address the challenge of long-range localization of surface targets using small-aperture two-dimensional (2D) planar arrays in deep sea , this study proposes a method that exploits the diversity of information embedded in deep-sea multipath acoustic propagation. By applying spatial beamforming to the 2D planar arrays, the horizontal azimuth, vertical elevation angles, and other corresponding multipath information of the target radiated noise are directly extracted. Based on geometric relationships, a localization algorithm model is established; its applicable conditions are derived, and the associated errors are analyzed and quantified. Numerical simulation results demonstrate that, when the prior knowledge is only ocean depth, the proposed method achieves a localization error less than 6% by utilizing the incident angle information of first-order reflected acoustic paths within a 10-km range from the target. This significantly enhances the generalization capability of 2D horizontal planar arrays for surface targets localization of in deep sea.