Researchers from the National Oceanography Centre (NOC) and the University of Southampton will ‘listen’ to a UK city for the first time at scale through its network of optical fibre cables using a ground-breaking new technology.
The researchers will be using a technique called distributed acoustic sensing (DAS) to capture sounds and vibrations throughout London and Southampton’s underground optical fibre networks.
Photo: Chaitawat Pawapoowadon
It’s part of a new project called SOUNDSCALE to explore the opportunities and risks this technology presents before it becomes more established and to determine priorities for future research.
The team are particularly interested in how DAS could be used in marine cities, such as Southampton, as an ‘early warning signal’ for flash floods, storm surges and other environmental hazards.
What is DAS?
DAS turns the optical fibres that support telecommunications networks into delicate sensor arrays that detect vibrations, like sound or movements.
As light travels along a fibre optic cable, a small amount scatters back due to natural imperfections in the glass, called Rayleigh backscatter. A vibration or disturbance anywhere along the length of the cable, such as from an earthquake, vehicle or even a footstep, influences this backscattered light.
DAS uses a highly sensitive instrument connected to one end of the fibre to detect these changes in the fibre’s ambient environment.
These are then processed by advanced algorithms to interpret the nature and location of the vibration.
Sound of a city
The research team consists of experts in physical sciences, engineering, computer science, political science, geography and arts and humanities.
London and Southampton have extensive optical fibre networks connected through the National Dark Fibre Facility (NDFF), enabling researchers to measure the ‘sound of a UK city’ for the first time at such a scale.
The team will be doing this in anticipation of the risks this technology might bring about.
“This technology poses potential risks to our privacy and security, opening up new opportunities for surveillance,” says co-investigator Dr Alexandra Anikina, a researcher in the University of Southampton’s Department of Art and Media Technology and Co-Director of Critical Infrastructures and Image Politics research group.
Engaging citizens
The team is planning to engage with citizens from both cities, through artistic exhibitions, policy workshops, and citizen panels that will help to steer the direction of further DAS research.
Prof Matt Ryan, co-investigator of the project and expert in public policy and democratic innovations from the University of Southampton says, “Too often new technologies change our lives before the public and policymakers have had a chance to engage with them in a meaningful way and consider what guard rails might be needed.
“With DAS we want to integrate citizens directly in its development and implementation so they can prioritise and anticipate issues before it is too late to change direction.”