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Hawk Measurement Praetorian Fiber Optic Sensing Perimeter Security and Threat Detection

The Praetorian Fiber Optic Sensing System can be installed along a fence or perimeter and can detect, identify and report any movements. This system has limitless applications and can be installed on anything from explosive storage areas to farms and ranches. The fast processing speed and pulse rate allow the Fiber Optic System to detect minute interferences that may otherwise go unnoticed. Some examples of detectable activates include intruder movement along a perimeter, intruders cutting or climbing a fence, vehicle movement along a perimeter and digging, excavating or trenching. The Fiber Optic Sensing system is crucial for keeping valuable assets secure and protected.

Principle of Operation:

Using a combination of Rayleigh backscatter and time of flight, the Praetorian determines the presence, location, intensity and frequency of vibrations along an optical fiber in real time.

Rayleigh backscatter responds to vibrations applied to the fiber. HAWKÍS signal analysis software allows the Praetorian to quicklydetermine the most likely origin of the vibration and report any error signals to security personnel without notifying an intruder of their detection.

The location of the vibration is determined using a “Time of Flight” calculation. When a laser pulse is emitted from the system a fast clock is started. As backscattered light is returned to the detector, it is recorded for further analysis and time stamped. Due to the speed of light being constant within a fiber this time stamp corresponds to a distance on the fiber.

How does it work?

Distributed Acoustic Sensing (DAS) continuously monitors Vibration, Sound and Acoustic Energy along the fiber using a process called Rayleigh Backscatter along the entire length of an optical fiber. Using a “time of flight” calculation on the laser pulse the position of any incoming signal can be determined to within a meter on up to 80 kilometres (50 miles) of fiber.

Distributed Temperature Sensing (DTS) and Distributed Strain Sensing (DSS) work in a similar way, but use a looped fiber within the sensing cable to detect both Temperature and Strain. The laser is sent down both sides of this loop and the interference pattern allows for Brillouin Backscattering to be measured revealing changes to Strain and Temperature within the fiber.

Praetorian has a built-in Field Programmable Gate Array (FPGA) which quickly records, processes and analyses the data collected by the system and detects and reports signals generated by problematic events within the environment.


  • No time splicing, allowing zero chance for an intruder to go unnoticed
  • Immune to the effects of a broken or cut fiber
  • Fiber optic sensing detects the exact location of intruder
  • Self-diagnostics monitor the unitÍs condition and maintain optimum performance
  • No maintenance or calibration require after commissioning
  • Monitor up at 80km (50mi) at the same time.
  • 24/7 real-time monitoring

What does Praetorian tell me?

Praetorian has a built in Human Machine Interface (HMI) and can be operated directly or connected to existing Control Systems (such as SCADA) via a digital communications protocol (Typically TCP/IP) and report:

  • The location of the alarm
  • The classification of the alarm
  • The alarms longitude and latitude
  • The intensity of the alarm
  • A time and date stamp of the alarm
  • And other detected conditions depending on the specific application

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