Near-field localization of airborne sources using deep-sea horizontal array

To achieve underwater detection and localization of airborne sound sources, a localization method using sound rays of different paths in the deep sea for focused beamforming is proposed, which realizes the localization of airborne sound sources in the Fresnel zone by seabed horizontal array. The analysis shows that the spatial spectrum produces pseudo-peaks when different path sound rays are directly utilized for focused beamforming localization. For this reason, a pseudo-peak suppression strategy based on sound ray arrival amplitude weighting is applied. Simulation and sea trial data verify the effectiveness of the method, which is able to locate fixed-wing aircraft targets flying at an altitude of about 5000 m and a horizontal distance in the range of 13–17 km, with an average positioning error of 0.9 km. Compared with the traditional method that only utilizes direct transmitted sound rays, the proposed method significantly improves the localization performance of long-range airborne sound sources.