相位敏感OTDR和布里渊OTDR结合的双参量分布式光纤传感的研究

在分布式光纤传感及应用中,单一传感系统一般只能实现一种参量的监测,如相位敏感光时域反射计(Φ-OTDR)只能监测光纤沿线的振动信息,布里渊光时域反射计(BOTDR)仅能监测应变/温度信息。对于多参量监测的应用场合,必须通过配合多种技术和系统来实现多参量监测和分析,增加监测成本和复杂性。设计并搭建了一种集成Φ-OTDR和BOTDR的双参量分布式光纤传感系统。该系统通过同时测量光纤中的瑞利散射和布里渊散射信号,在一根传感光纤中实现了温度/应变和振动的双参量检测。经过试验测试和验证,其测量距离达50 km以上,空间分辨率可达20 m,温度测量精度为±3℃,频率测量精度±0.15 Hz以上。

Research on dual-parameter distributed optical fiber sensing combined with phase sensitive OTDR and Brillouin OTDR

A single sensing system can only monitor one parameter in distributed fiber sensing and applications.For example,phase sensitive optical time domain reflectometer(Φ-OTDR)can only monitor vibration information along the fiber,and Brillouin optical time domain reflectometer(BOTDR)can only monitor strain/temperature information.Multi-parameter monitoring and analysis must be implemented with multiple technologies and systems in multi-parameter applications,which increase monitoring costs and complexity.A dual-parameter distributed optical fiber sensing system integratingΦ-OTDR and BOTDR was designed and built.The system achieves dual-parameter detection of temperature/strain and vibration in a sensing fiber by simultaneously measuring Rayleigh scattering and Brillouin scattering signals in the fiber.After testing and verification,the measurement distance is more than 50 km,the spatial resolution is up to 20 meters,the temperature measurement accuracy is±2℃,and the frequency measurement accuracy is above±0.15 Hz.