Liu Kuan-Wen, Huang Ching-Jer, Too Gee-Pinn, Shen Zong-You, Sun Yung-Da
Department of Hydraulic and Ocean Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
Coastal Ocean Monitoring Center, National Cheng Kung University, Tainan 70101, Taiwan.
Sensors (Basel). 2022 Mar 21;22(6):2420. doi: 10.3390/s22062420.
This study investigates the performance of a passive time-reversal mirror (TRM) combined with acoustic ray theory in localizing underwater sound sources with high frequencies (3-7 kHz). The TRM was installed on a floating buoy and comprised four hydrophones. The ray-tracing code BELLHOP was used to determine the transfer function between a sound source and a field point. The transfer function in the frequency domain obtained from BELLHOP was transformed into the time domain. The pressure field was then obtained by taking the convolution of the transfer function in the time domain with the time-reversed signals that were received by the hydrophones in the TRM. The location with the maximum pressure value was designated as the location of the source. The performance of the proposed methodology for source localization was tested in a towing tank and in the ocean. The aforementioned tests revealed that even when the distances between a source and the TRM were up to 1600 m, the distance deviations between estimated and actual source locations were mostly less than 2 m. Errors originated mainly from inaccurate depth estimation, and the literature indicates that they can be reduced by increasing the number of TRM elements and their apertures.
本研究探讨了一种无源时间反转镜（TRM）与声线理论相结合在高频（3 - 7千赫）水下声源定位中的性能。该TRM安装在一个浮标上，由四个水听器组成。使用射线追踪代码BELLHOP来确定声源与场点之间的传递函数。将从BELLHOP获得的频域传递函数转换到时域。然后通过将时域传递函数与TRM中水听器接收到的时间反转信号进行卷积来获得压力场。将压力值最大的位置指定为声源位置。在拖曳水池和海洋中对所提出的声源定位方法的性能进行了测试。上述测试表明，即使声源与TRM之间的距离高达1600米，估计声源位置与实际声源位置之间的距离偏差大多小于2米。误差主要源于深度估计不准确，并且文献表明可以通过增加TRM元件的数量及其孔径来减少误差。
