Distributed Acoustic Sensing (DAS) enhances existing railway applications and enables a variety of new ones.



DAS-based solutions for railway applications

During the last years Frauscher has conducted in-depth research into fibre sensing technologies and their viability within the railway industry. The study revealed that Distributed Acoustic Sensing (DAS) exhibits by far the highest potential for railway market application. As a result Frauscher has developed the DAS technology in concert with its axle counting and wheel detection systems into a suite of operational and approved products called Frauscher Tracking Solutions FTS.

In terms of being used within the railway industry, DAS based solutions for sure are still at a early stage. Nevertheless DAS has the potential to become the basis technology for train tracking, asset condition monitoring and security applications in the railway industry. In the long term it will provide operators with new possibilities to reduce expenses in terms of human and financial resources by contributing to maximise the efficiency of railway operations.

Distributed Acoustic Sensing

The principle of Distributed Acoustic Sensing (DAS) is based on changes in the intensity of light reflections caused by sound waves radiating against a singlemode fibre optic cable. These changes can be detected. Using specially developed algorithms it is possible to transform measurable signatures into valuable information about train movements, people on and near the tracks and additional activities such as manual and machine digging.

These DAS capabilities are in use in the oil, gas and border protection businesses. Any single-mode fibre can quickly be turned into a series of listening devices using DAS with minimal fibre work at either end of the monitored fibre section. Using spare capacity on the existing fibre cables next to a track makes it possible for similar and related applications to be realised for railway-specific requirements.


As a stand-alone solution FTS-FAS can be used for non-vital train tracking, basic applications in asset condition monitoring as well as security applications. It delivers the train’s position, velocity, direction, and more. Detecting rail defects or rock falls is just as possible as monitoring personnel, working parties and animal herds.


Integrating single wheel sensors on each track significantly increases the output’s quality as detected events and asset conditions can be localised more accurately. Thereby, FTS-FAS+ as an integrated solution with wheel detection systems enables precise train tracking on multi-track lines and enhances asset condition monitoring.


FTS-FAdC+ is the most advanced FTS combination. It consists of FTS-FAS and a modern axle counter, such as the Frauscher Advanced Counter FAdC. This combination provides valuable data to enable carrying out of complex and safety relevant applications, as the axle counter operates on a SIL 4 level.