Findings: X-ray specs for hole diggers

Devices that can "look" into the ground to "see" buried pipes, patches of contaminated soil and even underground geological structures have been developed by scientists, writes Steve Farrar.

The augmented-reality technology graphically overlays digitally stored information on the real world in real time via a headset or hand-held viewer.

It could revolutionise fieldwork in a host of industries, saving engineers from wasting time and money on test excavations to find hidden features. The disruption caused by the UK's utility companies digging up streets has been estimated to cost the economy £2 billion a year.

The technology might be developed to enable tourists to take a peek into a conjectured past, such the reconstructed Hadrian's Wall in situ , or to allow the public to examine how proposed buildings would fit into their neighbourhood.

It has been put together by two teams at Nottingham University, led by Bryan Denby, professor of minerals computing, with £650,000 funding from the Department of Trade and Industry's Foresight Link award scheme.

Gethin Roberts, a lecturer at Nottingham's Institute of Engineering Surveying and Space Geodesy and a leading member of the team, said a key element was locating the viewer to within a centimetre's accuracy and determining its orientation in real time.

The new technology does this by taking part of the global positioning system signal and comparing it with a fixed reference point. It then uses an inertial navigation system to track movement and determine orientation.

The system interrogates its database - which might be supplied by utility companies or from geological survey work - and converts this into an appropriate display.

This is overlaid on the real view to show the buried landscape, which is constantly adjusted as the observer moves.

The technology has been tested in three locations using Yorkshire Water's pipe database; in two locations, including a London borough, using a British Geological Survey database; and at an opencast mine in France owned by the mining company Rio Tinto.

The findings were presented at the Geographic Information Systems in Geology conference in Moscow earlier this month.