Scientists to map coast in 3-D

Sonar signals, like this of a shipwreck, are made 3-D

Scientists at Cardiff University have developed a way to produce a three-dimensional map of the seabed.

They claim their computer-made images are detailed enough to let them "walk" along a virtual map of the ocean floor.

The research uses underwater sound in the same way an ultrasound scan creates a picture of a baby in the womb.

Experts hope it will let them visualise the vast plains and mountains that lie at the bottom of the seas. They are to begin with the coast off south Wales.

The sonar images can also be used to scan the underside of ships

Scientists claim the development is a quantum leap in the use of information provided by traditional sonar-mapping techniques.

A sonar sensor trailed behind a boat produces a signal 60m either side of the vessel which is then analysed by computer and turned into a three-dimensional virtual image.

Dr Chris Wooldridge, Project Co-ordinator and Senior Lecturer in the School of Earth, Ocean and Planetary Science, said: "It turns the sea transparent for us.

"Traditionally, we have seen the seabed in two dimensions, on charts. That is insufficient for the demands of today.

"We can now take a depth of water and model into the three dimensions. We can routinely scan to a higher resolution and we can scan in real time."

Signals from a sonar sensor are the basis of the 3-D mapping

He said the system also has potential to protect ports or coastal areas which would be at risk of terrorist attack.

It is can be used in "real time" to track a diver or to scan a particular area - such a berth in a harbour - in enough detail to detect an intrusion.

The technology pioneered and patented in Wales is expected to be taken up by the oil and gas industry, the marine dredging industry and conservationists.

The security aspect of the development is undergoing tests in Florida to see how it can strengthen ports' defences against terrorist threats.

Mapping of the sea bed off Wales begins in March and continues until the winter storms making it impossible.

Seabed mapping

The areas to be surveyed include Swansea Bay, Milford Haven and Skomer marine nature reserve.

The campus has invested more than £200,000 in seabed mapping technology from Science Research Investment Fund (SRIF).

The project has a further £50,000 in computer software and hardware from CodaOctopus, a company specialising in underwater technologies for imaging, mapping, defence and survey.