Distributed Acoustic Sensing

AgilFence Distributed Acoustic Sensing System detects real-time sound signals along the entire length of the pipeline continuously without any blind points and interferences. It can monitor every points of the pipeline, locate the leakage and the third party intrusion event accurately, and identify the nature of the intrusion. After analysing the sound signals (frequency, amplitude, and phase) received from the optical fibre, an alarm will be triggered if the event is a threat to the pipeline.

Key Features

  • No blind zone along entire length of the pipeline
  • 24/7 Continuous monitoring
  • Define and record nature of intrusion
  • Early warning of threat to the pipeline
  • No maintenance required
  • Easy Deployment
  • No EMI/EMC and immune to lightning

Applications

  • Gas pipeline leakage detection
  • Third Party Intrusion (TPI)
  • Well Integrity
  • Pipeline Inspection Gauge (PIG) Tracking
  • Seismic Monitoring
How It Works

The AgilFence buried solution uses Phase-Sensitive Optical Time Domain Reflectometer (PS-OTDR) technology to achieve distributed acoustic sensing along an optical fibre cable up to 20km. When a coherent laser pulse is launched from AgilFence Sensing Unit into the fibre and gets detected by any third-party interference, Rayleigh backscattering occurs. This backscattering signals received will be analysed by the AgilFence Signal Processing Unit. By detecting temporary changes in frequency, amplitude and/or phase, AgilFence Distributed Acoustic Sensing can pick up vibration or acoustic signals caused by excavation activities. As the distance the light travelled can be easily calculated from the time of travelling, the excavation activities can be located accurately. With intelligent signal processing, false alarm will be eliminated and true alarm will be triggered and displayed to the user.