Title: Acoustic localization scheme and accuracy analysis for underwater vertical moving target using seabed stations

Author(s): ZHANG Xu; SUN Ao; XIN Jian; HAN Xu

Affiliation(s): Unit 91550 of PLA; Postdoctoral Scientific Research Work Station in Unit 92493 of PLA

Abstract: To measure the trajectory of an underwater vertical moving target (UVMT) in transient motion with high accuracy and high frame rate, an acoustic localization model using seabed stations with an acoustic beacon was presented. A solution algorithm based on the Gauss-Newton method was derived, which was shown to satisfy the local linear convergence. Accuracy analysis of the numerical simulation indicated that the station location, sound velocity, and signal time delay estimation errors were propagated to location parameters through measurement ranges, and the main affecting factors included the station geometry, target relative location, and acoustic conditions. Vertical accuracy was improved using a supplemental surface station coupled with the seabed stations. Detailed characteristics were indicated by accuracy distribution from the full test sea area. A 14-station array composed of 13 seabed stations and 1 surface station in a test sea of 1 km * 1 km and 60 m in depth demonstrated that the average root mean square errors (RMSEs) in the x, y, and z directions were 0.30, 1.47, and 0.34 m, respectively, in the vertical range of 35-60 m. This work provided a technical approach for UVMT localization, which would be useful for designing related measurement systems.