Multi-Parameter Fiber Sensing: A Comprehensive Technology Overview
The scientific literature on Distributed Optical Fiber Sensing (DOFS) deployed on submarine communication cables has achieved the first integration of intensity-phase-frequency parameters, enabling simultaneous measurement of:
Fiber loss and temperature
Ocean gravity waves and tides
Earthquakes and typhoons
Vessel activities
Acoustic and vibrational disturbances
Current submarine cable sensing approaches mainly include State of Polarization (SOP) detection, interferometric measurement, and Distributed Optical Fiber Sensing (DOFS). While SOP and interferometric techniques offer high sensitivity over long distances, they are limited in precisely localizing multiple disturbance events. In contrast, DOFS provides continuous and high spatial resolution measurements, enabling large-scale environmental monitoring based on existing submarine cable infrastructure .
This technological evolution supports a range of applications including:
Early detection of potential cable interference
Improved verification of physical contact events
Enhanced situational awareness when vessels operate near critical subsea routes
Detection of marine geophysical processes
Vessel activity monitoring
Tsunami and earthquake early warning
Industry Summary
The international hydrological observation cable industry in 2026 is characterized by:
Expanding Subsea Cable Infrastructure: New installations like INGV's 35 km cable in the Mediterranean and proposed Arctic routes through the Polar Connect expedition are extending observation networks into previously inaccessible regions
Distributed Acoustic Sensing (DAS) Advancements: Breakthroughs in multi-span sensing (OOI RCA) and operational integration (Tampnet/Starboard) are transforming subsea cables into continuous sensor arrays, enabling real-time monitoring of earthquakes, ocean waves, and marine life
Data Volume Challenge: Single cables can generate up to 86 terabytes of data per day, requiring advanced algorithms and AI-powered analytics for meaningful interpretation
Security Applications: DAS technology is being deployed for subsea cable protection, with operators like Elisa and infrastructure networks using fiber sensing to detect potential threats
SMART Cable Standardization: The first universal SMART Cable sensor system deployment demonstrates the viability of integrating scientific sensors into existing telecommunications infrastructure
Multi-Parameter Sensing: Research is advancing from single-parameter vibration measurements toward integrated sensing of temperature, strain, acoustic, and environmental data simultaneously
Freshwater Applications: Beyond marine environments, fibre optic sensing is expanding to reservoir and water management applications, as demonstrated by the Statkraft pilot project
