Simultaneous distributed temperature and disturbance sensing in single-mode fibre for power cable monitoring

A dual modality fibre sensing system for simultaneous monitoring of temperature and acoustic disturbances in power cables is demonstrated. The system combines Raman OTDR (Optical Time-Domain Reflectometry) and Rayleigh phase- OTDR and is based on a single shared laser source. The performance of the system is demonstrated with absolute temperature measurements in heated fibre sections and detection of echoes from disturbance events. To the best of our knowledge, this is the first single-source simultaneous temperature and disturbance sensing in single-mode fibre. Finally, it is demonstrated that localised temperature variations and acoustic disturbances, such as cable strumming and strike, can be detected in an onshore 30 kV power cable.