Distributed 3D hydro-acoustic localization method with curvilinear volumetric array using a single auto-submerged cable

Distributed optical fiber three-dimensional (3D) localization technology is of significant importance in underwater target tracking and maritime security. However, the strict requirements for sensing cable deployment pose a major obstacle to the practical application. In this paper, a distributed 3D hydro-acoustic localization method based on curvilinear volumetric array (CVA) is proposed. A single auto-submerged cable is utilized to build the CVA for detecting the acoustic field, the mapping relationship between the detected acoustic field and the source-cable position relation is obtained, and thus, the 3D position of underwater target is located. In the sea trial, the feasibility of the proposed method is verified with a 93 m cable and an acoustic source at different positions. The average localization error is 2.2 m with a standard deviation of 0.3 m at a lateral distance of 25 m, and the maximum localization range reaches 1100 m. Moreover, the localization robustness on array deployment deviation is studied in theoretical simulation, including horizontal offset, rotation, and local offset, and the tolerable deviation ranges are 9 m, 5°, and 10 m, respectively, which indicate the localization robustness on array deployment deviation. The proposed method addresses critical marine environmental challenges in the shallow water, including strict requirements of cable deployment and array time-variation, potentially advancing underwater target monitoring in marine environment.