USMART - smart dust for large scale underwater wireless sensing

Wireless sensor networks using radio technology are used to gather data in many applications for infrastructure monitoring, environment monitoring and security. However this technology cannot be directly applied under water since radio waves are absorbed by water. Technologies exist for underwater communication using acoustic waves (sound) to carry data but this is a complex and demanding task requiring sophisticated processing. Hence these devices are expensive (£5-20k), bulky and power hungry which has generally limited their use to relatively small numbers and short duration. This has prevented the large scale deployment of sensor networks underwater despite huge demand for monitoring of subsea assets and the marine environment. The aim of this project is to create a smart underwater sensing framework based on ultra-low-cost underwater communication and sensing devices ('smart dust'). Pilot studies at Newcastle University have demonstrated the feasibility of producing underwater acoustic communication devices known as "nanomodems" which use novel approaches to signal processing to vastly reduce hardware complexity, size and cost. These have manufacturing cost as low as £50, very low receiver power consumption, to enable long life from small batteries, and tiny dimensions. However they can achieve data transfer and positioning capabilities found in much more expensive devices, over distances up to 1km through water. The communication technology will be extended, to further increase data transfer speed and power efficiency, and low cost sensor modules will be developed, along with flexible interfaces for commercially available sensors, to create mass deployable wireless underwater sensor devices. Protocols will be developed to allow large numbers of units to share the same communication channel efficiently while intelligent sensor processing techniques will ensure that the sensor network reliably extracts the maximum information available from the limited resources available. Hence the system will allow users to fully exploit the power of mass deployment, the whole being far greater than the sum of the parts. This will transform underwater sensor networks to allow long term monitoring with high spatial resolution, frequent updates and near real-time data delivery in a way that has been previously been cost prohibitive and impractical.

With highly flexible sensor payload, the technology created may be applied to a wide range of monitoring tasks. However, the project will focus on three main demonstrator scenarios in close collaboration with industry & end users:
- subsea asset monitoring e.g. condition of subsea cables, risers, seabed installations
- marine environment / biodiversity monitoring - chemical or biological parameters
- sensor nets for underwater security - detecting sound emitted or magnetic disturbances from underwater threats

The novel contributions of this project will be:
- Disruptive, low-cost technology enabling mass deployment with battery life of several years.
- Large scale underwater monitoring (>100 devices) with high spatial resolution.
- Rapid deployment and online data delivery (as opposed to data logging and collecting later).
- Intelligent, adaptive sensing to maximise resource utilisation and fully exploit large scale.

To maximise the impact of the project, an open test-bed will be created near the Northumberland coast. Potential end-users from across the subsea sector will be invited to take part in a series of workshops to identify new opportunities in distributed underwater sensing, which will be prototyped and evaluated via trials using the test-bed. The ultimate measurable objective of the project will be to demonstrate a step change in the efficiency of subsea data gathering. This will be defined in terms of the data delivered (volume, quality, coverage) versus overall cost of operations (hardware cost, boat time, staff time, infrastructure cost).

The main impact generated by this project will be in the following areas

Offshore oil/gas & renewable energy
This project will bring about a step change in the feasibility of large scale monitoring for subsea assets such as cables, risers, seabed structures and marine energy devices. This will enable online, high resolution data to be gathered to assist in condition based maintenance of these assets, prolonging life, reducing through-life cost and mitigating the environmental and financial risk of failures. There are already examples where existing underwater communication technology is being combined with corrosion sensors for example but this is currently on a very small scale due to the cost, size and power consumption of the technology. This project has the potential to transform these applications.

Marine monitoring and governance
The cost of data gathering at sea, to support the study/monitoring of the marine environment and biodiversity, is vast. Organisations such as the Centre for Environment, Fisheries and Aquaculture (Cefas) have a pressing need for more efficient and cost effective technologies to measure a wide variety of parameters with ever increasing requirements on spatial resolution, timescales and area coverage. This sector is over reliant on logging devices which take a long time to deploy/recover (with boat time being a dominant cost) and data cannot be viewed until after recovery. Such devices are also frequently lost, costing money and data. Low cost, mass deployable wireless sensing with real time data transmission would revolutionise these operations and many possible use cases have been discussed with such organisations. The potential indirect benefit of improved and more widespread monitoring for the marine environment and those who depend on its resources (e.g. fisheries) is therefore very significant as is the potential for improved data to study ocean processes linked to climate change.

Defence/homeland security
The detection of underwater threats by dense networks of sensors is another application which is currently difficult to realise due to the cost, size and power consumption of current devices. This project makes the vision of underwater sensor nets defending strategically important ports and waterways a realistic one.

Water supply industry
Cost effective, long term sensor deployment in hard to access submerged environments would open up new possibilities in asset monitoring and operational management in the water industry.

Subsea equipment manufacturers
The outputs of the project will be exploited in the form of new families of ultra-low cost/power, miniature communication and sensing products for underwater applications. The project will have close links to several manufacturers of such devices and a clear route to the commercialisation of these new technologies. Such devices are sold globally for a vast range of applications and substantial economic benefits are anticipated.

Beyond these areas, the extensive programme of end-user engagement planned for the project will help to identify many more application areas and the open test-bed to be created will allow realistic trials to assess the feasibility and value of these applications.