Laser plane to look for South Downs secrets

It is just one of hundreds of joint initiatives set out in the first ever Partnership Management Plan for the South Downs National Park, launched in January 2014.

While the South Downs is famous for Iron and Bronze Age monuments such as Cissbury Ring and Winchester Hill, a large part of the central areas of the National Park lie under forests or woodland, meaning that almost nothing is known about their ancient history .

The Piper Chieftain survey aircraft will be using airborne laser technology (commonly known as LiDAR) to map the ground underneath 30,000 ha of woodland between the river Arun and the A3.

The LiDAR survey is the start of a three-year Heritage Lottery Funded project investigating the hidden archaeology underneath the South Downs’ ancient woodlands. Once the 3D map has been created local archaeologists and community groups will be recruited from Autumn 2014 to investigate these sites further. The project will provide lots of new information, linking today’s communities to the people have lived in and cared for this landscape for the last 6000 years.

Rebecca Bennett from SDNPA said:“This is the first time that the area under the trees will be mapped in detail. A LiDAR sensor fitted in the plane scans the ground using a laser and records the reflected light. Because some of the light passes through the forest canopy and reflects from the ground below, we can use these measurements to calculate a high-resolution 3D model of all the ‘lumps and bumps’ beneath the trees that are otherwise obscured and impossible to map.

“It’s a unique opportunity to unlock the secrets underneath these ancient woods. There are a few archive aerial photographs of this area capturing a tantalising glimpse of features revealed by felling during WWII, but there is so much that we don’t know about the history of the people who lived here.”

“We have seen a marked increase in the use of airborne LiDAR surveys for archaeological investigation,” said Chris Boreland of Fugro “A major benefit of LiDAR mapping is the rapid collection of a high accuracy 3D terrain model of the survey area that could take months or even years to undertake by conventional survey teams. Over the years Fugro’s FLI-MAP system has surveyed many heritage sites, including Neolithic funerary monuments, medieval settlements in Ireland, and UNESCO designated World Heritage Sites such as Stonehenge and St. Kilda. The resulting datasets and imagery constitute an invaluable and spectacular research tool and an unparalled means of preserving our landscape and heritage for future reference.’

James Kenny, Archaeology Officer at Chichester District Council, said:

“We are delighted to be involved in this project. We know there is the potential for fascinating discoveries to be made and it is exciting that we will soon know a lot more about this ancient landscape.”

The project is led by the South Downs National Park Authority, in partnership with Chichester District Council and with the support of West Sussex and Hampshire County Councils.

Report contributed by the South Downs National Park Authority.