Fibre Optic Sensing Systems

Advanced Distributed Sensing for Real-Time Infrastructure Monitoring

Telecommunications companies are increasingly turning to real-time, integrated Optical Time Domain Reflectometers (OTDRs) for round-the-clock performance and failure monitoring. The precision of OTDR measurements is crucial for effective network management. Modern OTDRs can detect events with a resolution of less than a metre, allowing for pinpoint accuracy in fault location.

More advanced fibre optic sensing technology transforms a standard optical fibre into a highly accurate and continuous sensor, capable of detecting vibrations, acoustic events, temperature variations, strain, and environmental changes along its entire length. Unlike traditional point sensors, fibre optic sensing provides thousands of continuous monitoring points, delivering unparalleled data accuracy and coverage in real-time.

At Dedicom A/S, we provide cutting-edge Distributed Acoustic Sensing (DAS), Distributed Temperature and Strain Sensing (DTSS), and Distributed Temperature Sensing (DTS) solutions. Utilizing advanced Brillouin-OTDR and Raman-OTDR technologies, our fibre optic sensing systems enable precise, real-time monitoring across extensive infrastructure.

Why Fibre Optic Sensing?

Traditional monitoring approaches rely on discrete point sensors each requiring individual installation, power supply, and maintenance. For infrastructure spanning tens or hundreds of kilometres, this approach quickly becomes impractical and cost-prohibitive. Fibre optic sensing fundamentally changes this equation by transforming the optical fibre itself into a continuous sensor array.

A single fibre optic cable can provide thousands of measurement points along its entire length, detecting changes in temperature, strain, vibration, and acoustic signals with remarkable precision. This means comprehensive coverage without the complexity and cost of deploying thousands of individual sensors. The fibre is passive, requiring no electrical power along its length, and is inherently immune to electromagnetic interference making it ideal for harsh industrial and high-voltage environments.

Our Technology Portfolio

Distributed Acoustic Sensing (DAS) DAS technology detects acoustic vibrations and dynamic strain along the entire length of an optical fibre. By analyzing the backscattered light from laser pulses, DAS systems can identify and locate events such as ground disturbances, vehicle movements, machinery vibrations, and intrusion attempts. With spatial resolution as fine as one metre and sensing ranges exceeding 100 kilometres, DAS provides unprecedented situational awareness for pipeline security, perimeter protection, and seismic monitoring.
Distributed Temperature Sensing (DTS) DTS systems measure temperature continuously along an optical fibre using Raman scattering analysis. Temperature profiles are captured in real-time with spatial resolution of approximately one metre and temperature accuracy within ±0.5°C. DTS is essential for applications including fire detection in tunnels and cable galleries, thermal monitoring of power cables, and process temperature tracking in industrial facilities.
Distributed Temperature and Strain Sensing (DTSS) DTSS combines temperature and strain measurements in a single system using Brillouin scattering techniques. This dual-parameter sensing is invaluable for structural health monitoring, where both thermal effects and mechanical stress must be understood. DTSS enables early detection of structural fatigue, ground movement, and material degradation across bridges, pipelines, dams, and other critical infrastructure.
Integrated OTDR Monitoring Our integrated OTDR solutions provide continuous, automated monitoring of optical fibre networks. Real-time fault detection, event location, and performance trending ensure that network operators are immediately aware of any issues affecting their fibre infrastructure. Sub-metre event resolution enables precise fault location, minimizing repair times and service disruption.

Key Highlights

Continuous Monitoring Coverage Unlike point sensors that leave gaps between measurement locations, fibre optic sensing provides truly continuous coverage. Every metre of fibre acts as a sensor, ensuring that no event goes undetected regardless of where it occurs along the monitored path.
Exceptional Spatial Resolution Modern fibre optic sensing systems achieve spatial resolution as fine as one metre over distances exceeding 50 kilometres. This precision enables accurate event location, reducing investigation time and enabling rapid response to detected anomalies.
Real-Time Detection and Alerting Events are detected and reported within seconds of occurrence. Automated alerting ensures that operators are immediately notified of significant events, while intelligent algorithms filter out background noise and normal activity to minimize false alarms.
Passive, Intrinsically Safe Operation The sensing fibre requires no electrical power along its length, making it inherently safe for use in hazardous environments including explosive atmospheres, high-voltage installations, and chemically sensitive areas. No active electronics in the field means no spark risk and no equipment to maintain in remote locations.
Electromagnetic Immunity Optical fibres are completely immune to electromagnetic interference, making them ideal for deployment alongside high-voltage power systems, in electrically noisy industrial environments, and in applications where EMI would compromise traditional electronic sensors.
Long-Range Capability Single sensing units can monitor fibre lengths exceeding 100 kilometres, enabling cost-effective coverage of extensive linear infrastructure such as pipelines, power cables, railway lines, and telecommunications routes.
Leverage Existing Fibre Assets In many cases, existing dark fibres within cable infrastructure can be repurposed for sensing applications, transforming unused assets into valuable monitoring tools without additional fibre installation.
Minimal Maintenance Requirements With no active components in the field and no consumables to replace, fibre optic sensing systems offer exceptionally low maintenance requirements. The interrogation unit at the monitoring station is the only active equipment requiring periodic attention.

Key Applications

Our fibre optic sensing systems are widely used in industries where real-time structural and environmental monitoring is critical:

Telecommunications

Fibre Optic Cable Monitoring: Detect cable overstress, fibre aging, microbends, and environmental damage before they cause service-affecting failures. Continuous strain monitoring identifies cables under mechanical stress, enabling proactive intervention.
Aerial and Buried Cable Protection: Monitor for third-party interference, excavation activity near buried routes, and environmental threats to aerial cables. Real-time alerts enable rapid response to prevent cable damage.
Network Performance Trending: Track long-term changes in fibre characteristics to predict maintenance needs and optimize network performance.
Fault Location and Diagnosis: Pinpoint fault locations with sub-metre accuracy, dramatically reducing repair times and minimizing service disruption.

Oil and Gas

Pipeline Integrity Monitoring: Detect ground movement, third-party interference, and mechanical stress that could compromise pipeline integrity. Early warning enables preventive action before leaks or failures occur.
Fatigue Monitoring: Continuous strain measurement identifies pipeline sections experiencing cyclic stress and material degradation, enabling condition-based maintenance strategies.
Leak Detection: DTS and DAS technologies detect the thermal and acoustic signatures of pipeline leaks, enabling rapid identification and precise location of even small leaks before they escalate.
Flow Line Blockage Detection: Temperature profiling identifies flow restrictions and blockages in real-time, preventing production losses and equipment damage.
Reservoir Monitoring: Downhole DTS provides continuous temperature profiles for reservoir characterization, production optimization, and injection monitoring.
Thermal Oil Recovery: Monitor steam-assisted gravity drainage (SAGD) and other thermal recovery processes with precise temperature tracking along horizontal wells.
Subsea Pipeline Monitoring: Fibre optic sensing enables continuous monitoring of subsea pipelines where traditional sensor deployment is impractical or impossible.

Power and Utilities

Underground Cable Monitoring: Continuous temperature monitoring of high-voltage underground cables ensures operation within thermal limits, preventing premature aging and enabling dynamic rating optimization.
Overhead Line Monitoring: DTS on overhead transmission lines enables real-time conductor temperature measurement for dynamic line rating, maximizing transmission capacity while ensuring safe operation.
Substation Fire Detection: Linear heat detection using DTS provides comprehensive fire monitoring in substations, cable tunnels, and transformer galleries.
Dam and Levee Monitoring: Detect seepage, internal erosion, and structural movement in earth dams and flood protection structures through distributed temperature and strain measurement.

Transportation Infrastructure

Railway Monitoring: Track bed stability monitoring, rail break detection, and level crossing security using DAS technology. Real-time detection of track geometry changes and unauthorized track access enhances safety and security.
Tunnel Monitoring: Fire detection, structural health monitoring, and ventilation optimization in road and rail tunnels using DTS and DTSS.
Bridge Health Monitoring: Continuous strain and temperature monitoring identifies structural stress, fatigue, and environmental effects on bridge structures, enabling condition-based maintenance.
Airport Perimeter Security: DAS-based intrusion detection for runway and perimeter protection, detecting and locating unauthorized access attempts in real-time.

Security and Perimeter Protection

Border and Perimeter Security: Detect and locate intrusion attempts along fences, buried perimeters, and sensitive boundaries using DAS vibration detection.
Critical Infrastructure Protection: Secure power stations, data centers, military installations, and other high-value facilities with continuous acoustic monitoring.
Pipeline and Cable Route Security: Detect excavation activity, vehicle movements, and unauthorized access along buried infrastructure corridors.

Mining and Geotechnical

Slope Stability Monitoring: Detect ground movement and early warning signs of slope failure in open-pit mines and natural slopes using distributed strain sensing.
Tailings Dam Monitoring: Continuous monitoring of tailings storage facilities for seepage, structural movement, and internal erosion.
Tunnel and Shaft Monitoring: Structural health monitoring during construction and operation of underground mining infrastructure.
Geothermal Monitoring: Temperature profiling for geothermal resource characterization and production optimization.

Industrial and Process

Fire Detection: Linear heat detection in warehouses, conveyor systems, cable trays, and industrial facilities where conventional point detectors cannot provide adequate coverage.
Process Temperature Monitoring: Continuous temperature profiling along reactors, pipelines, and process vessels for quality control and safety monitoring.
Structural Health Monitoring: Strain and temperature monitoring of industrial structures, storage tanks, and pressure vessels.

Advanced Technology

Brillouin-OTDR Technology Brillouin scattering-based sensing enables simultaneous measurement of temperature and strain with high accuracy over long distances. The frequency shift of Brillouin-scattered light is directly proportional to both temperature and strain, allowing precise measurement of both parameters. Our Brillouin-OTDR systems achieve temperature resolution of 0.1°C and strain resolution of 2 microstrain over distances exceeding 50 kilometres.

Raman-OTDR Technology Raman scattering-based DTS provides accurate temperature measurement independent of strain effects. The intensity ratio of Stokes and anti-Stokes Raman-scattered light is directly related to temperature, enabling absolute temperature measurement along the fibre. Raman-OTDR systems are ideal for applications where temperature is the primary parameter of interest, such as fire detection and power cable monitoring.

Coherent OTDR for DAS Distributed Acoustic Sensing uses coherent detection of Rayleigh backscatter to measure dynamic strain and vibration along the sensing fibre. Phase changes in the backscattered light caused by acoustic disturbances are detected and processed to extract vibration frequency, amplitude, and precise location information.

System Integration and Services

Turnkey Solutions Dedicom provides complete fibre optic sensing solutions, from initial consultation and system design through installation, commissioning, and ongoing support. Our engineers work closely with customers to understand their specific monitoring requirements and deliver systems optimized for their applications.

Integration with Existing Systems Our sensing systems integrate seamlessly with existing SCADA, network management, and security systems through standard protocols and APIs. Alarm outputs, data feeds, and remote access capabilities ensure that fibre optic sensing data is available where and when it's needed.

Training and Support Comprehensive training ensures that your operations team can effectively operate and maintain the sensing system. Ongoing technical support and software updates keep your system performing at its best throughout its operational life.

Partner with Dedicom

Fibre optic sensing represents a paradigm shift in infrastructure monitoring transforming passive optical cables into active, intelligent sensing networks. With extensive experience in telecommunications, energy, and industrial applications, Dedicom is your trusted partner for fibre optic sensing solutions that deliver actionable insight and protect your critical infrastructure.