Department of IOT Engineering, Hohai University, Changzhou 213022, China.
State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China.
Sensors (Basel). 2018 Oct 22;18(10):3586. doi: 10.3390/s18103586.
The ultra-short baseline positioning system (USBL) has the advantages of flexible application and easy installation, and it plays an extremely important role in the underwater positioning and communication. The error of the USBL in underwater positioning is mainly caused by a ranging error due to ray tracing, a phase difference error of the USBL, and acoustic noise in the underwater communication. Most of these errors are related to the changes in the sound speed during its propagation through the ocean. Therefore, when using the USBL for underwater detection, it is necessary to correct the sound speed profile in the detection area and optimize the ray tracing. Taking into account the actual conditions, this paper aims at correcting the model of underwater sound speed propagation and improving the tracking method of sound lines when the marine environment in the shallow sea area changes. This paper proposes a combined ray tracing method that can adaptively determine whether to use the constant sound speed ray tracing method or the equal gradient ray tracing method. The theoretical analysis and simulation results show that the proposed method can effectively reduce the error of slant distance in USBL compared with the traditional acoustic tracking method and the constant sound speed ray tracing method. The proposed sound ray correction algorithm solves the contradiction between the number of iterations and the reduction of positioning error and has engineering application value.
超短基线定位系统（USBL）具有应用灵活、安装方便的优点，在水下定位和通信中发挥着极其重要的作用。USBL 在水下定位中的误差主要是由声线跟踪的测距误差、USBL 的相位差误差和水下通信中的声噪声引起的。这些误差大多与声在海洋中传播过程中的声速变化有关。因此，在使用 USBL 进行水下探测时，有必要对探测区域的声速剖面进行修正，并优化声线跟踪。考虑到实际情况，本文旨在修正水下声速传播模型，并改进浅海区域海洋环境变化时的声线跟踪方法。本文提出了一种自适应确定是否使用恒定声速声线跟踪方法或等梯度声线跟踪方法的组合声线跟踪方法。理论分析和仿真结果表明，与传统的声学跟踪方法和恒定声速声线跟踪方法相比，所提出的方法可以有效地降低 USBL 的斜距误差。所提出的声线修正算法解决了迭代次数和定位误差减少之间的矛盾，具有工程应用价值。
