相位敏感光时域反射仪由于具备监测范围广、灵敏度高等优点被广泛应用于周界安防等领域。近年来，研究者对其光学系统的改进使得传感距离更长、空间分辨率更高。但需要处理的数据量大大增加，且环境噪声以及扰动类型多样给分布式扰动传感系统的实际应用带来了挑战。本文总结了提高该系统信号信噪比、扰动识别率等性能指标的信号处理方法，包括降噪算法、特征提取算法、机器学习以及深度学习算法，尽可能地对比各种算法的优劣，并展望了未来该领域信号处理方法可能的发展方向。

We present a theoretical analysis and an experimental study of the impacts of external optical feedback on dual-frequency fiber lasers. The external optical feedback can effectively suppress the phase noise of the beat notes of dual-frequency fiber lasers, provided some requirements are satisfied. The polarization of the optical feedback is important for the fiber laser’s stability, and it can also tune the beat note frequency. A side effect of external optical feedback, as demonstrated in the experiments, is lowering the sensitivity of the dual-frequency fiber laser-based sensors, although such degradation is not obvious.