【摘要】 相位敏感光时域反射计(Φ-OTDR)存在传感距离和空间分辨率相互制约的问题，提出了一种多相位编码调制方法实现高空间分辨率下的长距离传感。分析了多相位编码离散采样过程，设计了多相位编码的调制与解调控制策略；依据脉冲时域压缩原理，构建了匹配滤波器，通过调整编码参数，提升了脉冲压缩性能。实验证明，在3.8 m空间分辨率下，与传统单脉冲调制方法相比，所提方法可将20.4 km光纤尾端的信噪比由10.3 dB提升至43.5 dB,在95.6 km传感光纤尾端信噪比仍可达到12.1 dB,能够精准定位振动位置并实现相位还原。研究表明，所提方法实现了Φ-OTDR系统高空间分辨率下的长距离传感，为进一步提升Φ-OTDR传感性能提供了新的解决思路。更多还原

【Abstract】 To overcome the trade-off between long sensing distance and high spatial resolution in phase-sensitive optical time domain reflectometry(Φ-OTDR),a multivariate phase encoding modulation Φ-OTDR is proposed. The discrete sampling process has been analyzed and the modulation and demodulation control strategy has been designed. By leveraging the principles of pulse time domain compression, a match filter system has been constructed, which allows for adjusting encoding parameters to achieve enhancement of pulse compression performance. Experimental results demonstrate that, compared to conventional single-pulse modulation methods, the signal-to-noise ratio at the end of the 20.4 km optical fiber is significantly extended to from 10. 3 dB to 43.5 dB at 3.8 m spatial resolution, and the signal-to-noise ratio at the end of the 95.6 km optical fiber can still reach 12.1 dB,and it is able to accurately locate the vibration position and achieve phase recovery. The proposed method realizes the long distance sensing the Φ-OTDR system under high space resolution, providing new solution rhtought for further improving the sensing capability of Φ-OTDR.更多还原