Various security monitoring applications used in the rail industry require individual systems, creating expensive and complex integrations for surveillance centres. In addition, installations tend to be short-range and handled on a local level, increasing costs and inefficiency. Often, security patrols are required to conduct random checks throughout the network.
An ideal safety and security system for rail networks should address several minimum requirements, including:
• the ability to detect trespassers
• guarantees towards employee and passenger safety
• the protection of assets and infrastructure
• improvement of operational efficiency.
Fibre Optic Acoustic Detection (FOAD) is a proven technology being utilised for security in other industries, especially in the oil and gas sectors. In many cases, there already exists multicore, single-mode fibres that are buried along rail rights-of-way as part of different regions’ telecommunication networks. It is common practice among telecoms operators to install more cores than are needed, so it’s often possible to utilise one of these dark strands to enable a fiber optic-based detection system.
This technology utilises a process called Rayleigh Backscatter – when light is pulsed down the fibre, minute reflections can be detected throughout the length of the cable. Changes in these millions of reflections can be evaluated, allowing FOAD to measure the acoustic vibrations within the physical fibre. In effect, the fibre is transformed into a continuous sensor that works like a string of microphones.
The measured backscatter changes can be translated into acoustic signatures. By developing appropriate algorithms, it is possible to connect these signatures to monitor the movement and condition of rail vehicles and track assets, as well as to provide additional safety and security elements. Examples of these security applications include: dangerous vehicle or track conditions, trespassers, track worker location, digging, cable tampering, nearby vehicles and railroad structure approaches. Each of these applications rely on detailed knowledge of the infrastructure and fine-tuning of the appropriate algorithms.
Frauscher Sensor Technology has adapted FOAD for the rail industry with its Frauscher Tracking Solutions FTS platform. FTS allows continuous surveillance of all events occurring along extensive sections of track in real time, using minimal hardware. Innovative algorithms classify individual acoustic signatures to generate valuable information, generate alerts, and collect data for further evaluation. FTS can isolate events to within 30 feet or less, depending on the location and installation method of the fibre used.
Forwarding critical system data and linking it with additional information further increases the potential of the applications. For example, interfaces to safety equipment can be used to provide alarm messages via email or SMS, allowing operators to pinpoint security issues and quickly communicate with personnel via mobile devices. This data can also aid in the deployment of advanced technologies such as drones, which can be sent to precise locations. This response time reduction can have potentially drastic impacts on the outcomes of security issues.
Ongoing development with rail operators continues to demonstrate the potential of this technology, while allowing its further development. Dynamic views of their network operations, coupled with enhanced situational awareness, combine to improve the overall safety, security, and efficiency of rail networks.