How Distributed Acoustic Sensing (DAS) From Sensonic Works
Distributed Acoustic Sensing solution from Sensonic require only a single-mode optical fibre to gather vibration data. The connected Sensonic unit launches laser impulses down the fibre and monitors the signal reflected back.
Acoustic sound waves radiating against the fiber cable create structure-borne deviations. This alters the backscatter of the pulses that are reflected back towards the source.
The change in reflection is measured as a function of the time that has elapsed since the emission of the laser pulse. That’s how the cable becomes a sensor that can monitor vibrations along tens of kilometres of track. The vibration or change in vibration reveals a lot about the railway infrastructure. Various railway insights are revealed by the vibrations detected such as:
- Track Condition Monitoring
- Trespass / Walking / Digging near or on the track
- Cable events such as tampering or theft
- Landslide and Rockfall detection
- Accurate localisation of electrical flashovers
