Scanners create 3-D view of city

PAUL GORMAN

Last updated 05:00 07/05/2011

 

A vehicle cruising Christchurch streets has been recording details of earthquake damage to build up a three-dimensional model of what the city looks like.

The data-capturing system, connected to a computer inside a Nissan Pathfinder, has two 360-degree scanners collecting 600,000 points of information a second.

It also has four cameras, three looking forward and up at a 45deg angle and one looking down at the road and footpaths behind the vehicle.

The camera images are being taken every three metres along the road.

United States electronics and technology company Trimble lent the system free to its New Zealand distributor, GeoSystems in Christchurch, to help assess damage to buildings and infrastructure.

GeoSystems business development manager Martin Hewitt said the MX8 mobile system had been driven through the red zone and had surveyed many of the hill suburbs and Sumner and Redcliffs, recording all roads, buildings and bridges.

"One of the advantages of it is you can drive at pretty normal road speeds, though through the red zone we only went at about 25kmh, mostly because there were still obvious obstructions," he said. "Later, these [images] can be matched with data captured by LiDAR (light detection and ranging) aerial mapping and terrestrial scanning data, which will give a 3-D model of what the city looks like."

The system came to Christchurch from its latest job in Australia and finished its city work on Thursday, he said.

Trimble had also lent a scanner that was able to tell whether a building had moved or was on a lean.

"At the Arts Centre or either of the cathedrals, it can produce an extremely detailed 3-D model of the building prior to any deconstruction of the building. The model can then be used to plan the reconstruction and rebuilding," Hewitt said.

"Subsequent scans can ... be used to monitor the rebuilding progress ... the images captured can ensure that the exact stones are put back in their original positions."