关键词: 相位敏感光时域反射计, 分布式光纤传感, 多线程, 实时系统

Abstract: In order to meet the real-time monitoring requirements of the sensing system of phase-sensitive optical time-domain reflectometer (Φ-OTDR), this paper proposes a phase extraction algorithm based on the single-sideband spectrum interception of the signal (SSB-SI) and applies the combination of multi-threaded structure and heterogeneous parallel computation with a central processor (CPU) plus a graphic processor (GPU) to achieve the real-time processing of the data in the Φ-OTDR system, which can meet the demodulation requirements of hundreds of megabytes of data per second. The experimental results show that the Φ-OTDR system based on the phase extraction algorithm of this single-sideband spectrum will compress the monitoring phase demodulation time by about 21.1% while keeping the stable performance (e.g., spatial resolution, noise background), and at the same time reduce the size of the output data file, which improves the data storage efficiency by nearly 70% and achieves the real-time storage of monitoring data. This method significantly reduces the data processing rate requirement and system development cost of the real-time Φ-OTDR hardware system, which is of great significance for the application and promotion of the Φ-OTDR system.

Key words: phase-sensitive optical time-domain reflectometer, distributed fiber optic sensing, multithreading, real-time system