In this letter, a distributed optical fiber hydrophone (DOFH) based on Φ-OTDR is demonstrated and tested in the field. The specially designed sensitized optical cable with sensitivity up to −146 dB rad/µPa/m is introduced, and an array signal processing model for DOFH is constructed to analyze the equivalence and specificity of the distributed array of acoustic sensors. In the field test, a 104-meter-long optical cable and a Φ-OTDR system based on heterodyne coherent detection (Het Φ-OTDR) is utilized, and underwater acoustic signal spatial spectrum estimation, beamforming and motion trajectory tracking with high accuracy can be realized. As far as we know, this is the first report on the field trial of DOFH based on Φ-OTDR. The DOFH has the potential to achieve an array range of tens of kilometers, with elements spaced up to the meter level and flexible configuration, which has a broad application prospect for marine acoustic detection.

中文翻译：

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基于Φ-OTDR的分布式光纤水听器及其现场测试

在这封信中，已演示并测试了基于Φ-OTDR的分布式光纤水听器（DOFH）。介绍了专门设计的灵敏度高达-146 dB rad / µPa / m的敏化光缆，并构建了用于DOFH的阵列信号处理模型，以分析声传感器分布式阵列的等效性和特异性。在现场测试中，使用了104米长的光缆和基于外差相干检测（HetΦ-OTDR）的Φ-OTDR系统，并且可以高精度地进行水下声信号空间频谱估计，波束形成和运动轨迹跟踪被实现。据我们所知，这是基于Φ-OTDR的DOFH现场试验的第一份报告。DOFH有可能达到数十公里的射程，