Helios® DAS Interrogator Unit

Harness the power for fibre optics

Helios® DAS

What is Helios DAS?

Helios, the Distributed Acoustic Sensor (DAS) from Fotech, is a revolutionary sensing technology that converts up to 80km of standard communications fiber into a linear array of discrete vibration sensors. Activities such as hot-tapping pipelines, leaks, perimeter intrusion, frac operations in oil-wells and monitoring the health of trains on railways can be monitored, classified and reported on, locating positions to within a few metres.  

How does it work?

The Helios DAS system is an advanced variant of Optical Time Domain Reflectometer (OTDR) instrumentation that monitors the coherent Rayleigh backscatter noise signature in a fibre optic cable as pulsed light is sent into the fibre. The coherent Rayleigh noise generates fine structure in the backscatter signature of the fibre cable.  The Helios system focuses on the Raleigh component to increase its prominence in the backscatter trace.

Helios has been optimised to measure small changes in coherent Rayleigh noise structure that occur from pulse to pulse. Since the coherent Rayleigh noise structure is generated interferometrically within the fibre by the relative locations and strengths of local scattering centres intrinsic to the structure of the glass, very small physical (acoustic or vibration) disturbances at a point in the fibre can make detectable changes in the interferometric signal.

What makes Helios versatile?

The system operates with standard telecommunication grade optical fibres that can be installed as an operation is being developed or retrospectively on existing infrastructure. Utilising optical fibres means the system is immune to EM or RF interface.  It is also inert and requires no power along the entire sensing length beyond the interrogator unit, which aids the delivery of a simple installation, at a lower deployment cost and generates a considerable reduction in “through life” and maintenance costs.

What are its applications?

Fotech Solutions prides itself on its expertise and innovation as it provides dynamic solutions to the Oil and Gas industry. The company continues to deliver cutting edge technologies to an industry that demands greater levels of information and clarity from its complex and unconventional operations.
Helios DAS continues to enhance operations in a range of industries:

  • Pipeline and Asset Third Party Intrusion (TPI) Monitoring
  • Pipeline Leak Detection
  • Perimeter and Border Protection
  • Oil & Gas well monitoring and optimisation
  • Oilfield Seismic Applications, including VSP


The Helios DAS system is an adaptable technology capable of providing an invaluable layer of intelligence for a range applications and industries.Fotech Solutions continues to push the boundaries of Distributed Acoustic Sensing, with the Helios DAS evolving to successfully meet industry’s challenges and lead the way in the sensing revolution.