Underwater Positioning Analysis and System Establishment of the Towed Underwater Hydrophone Array System

The aim of this study is to establish an underwater towed hydrophone array detection and positioning system, which serves as a rescue device for detecting flight recorders in the event of a maritime accident. By using Time Difference of Arrival (TDOA) to calculate the azimuth of the underwater locator beacon (ULB) which is located inside the black box, the position of the flight recorder can be obtained. The underwater towed hydrophone array detection and positioning system was tested for a three-day experiment in the waters off the southwest coast of Taiwan. The azimuth of the sound source was determined by using two frequencies generated by different types of underwater locator beacons (37.5 kHz and 8.8 kHz) and post-processing. The accuracy of the positioning was achieved by controlling the depth of the underwater hydrophone array. This study can deduce the location of the underwater locator beacon through subsequent positioning analysis, which can be used by search and rescue teams in the future to improve the efficiency of the rescue process.