Heritage Open Days 9-18 September 2022 - What will you discover?

Astounding Inventions - Archaeology

LASERS! Yep, not the answer I expected when I asked colleagues for their pick of the most astounding innovations in archaeology! But there you go. Now we are not talking lightshows* after dark at the dig, or evil masterminds of science fiction,* though the science part is right. Laser technology has helped archaeology jump light years. Here are two brilliant members of the National Trust’s archaeology team to explain.

*genuine answers for what people think of when you say ‘lasers!’

Brightly coloured laser scanned image of a prehistoric room carved into rocks at Kinver EdgeLaser scanning of prehistoric rock rooms at Kinver Edge reveals exceptional details invaluable for future work © Trent and Peak Archaeology

See more with a bird’s eye view

Gary Webster – Heritage Officer, Changing Chalk (supported by NLHF)

Side by side aerial views of Friston Forest. The photograph shows the land covered in trees. The laser scan shows the lumps  and bumps hidden beneath.

Friston Forest: Laser scan (R) reveals features hidden by tree cover in photographs / © Historic England Aerial Archaeology Mapping Explorer

One of the great shifts in modern archaeology, both in identification of features and the recording of them, is in the accessibility of aerial photography. This is both from satellites, and more recently with drones (both recreational and professional). The prevalence of aerial photography has opened the door to other aerial scanning techniques, such as airborne laser scanning, or LiDAR. LiDAR was originally created in the 1960s from technology created to track satellites and military targeting and has been adapted by canny geographers and archaeologists. The technology helps us to see beneath tree canopies and foliage, as the lasers can penetrate through to the ground. This allows for a true representation topography to be created and analysed, enabling the discovery of archaeological features which were no longer visible from the air, or the ground.

Mapping change

Alicia Biles - Historic Environment Advice Assistant Apprentice

Contrasting aerial images of Croft Ambrey. The photograph shows the general landscape. The laser scan in black and white shows more precise detail in the topography.

Croft Ambrey: The level of detail provided by LiDAR will help us monitor erosion and plan for the future of this site / © National Trust

Laser scanning is a technological advancement in survey recording that provides high quality data through a non-intrusive technique. It is used in two main forms in recording archaeology: airborne laser scanning (also commonly known as LiDAR) and terrestrial laser scanning. Both provide high quality and accurate data to record, conserve and monitor archaeology within the Historic Environment. They allow detailed mapping of sites and can be used to identify new features, as well as help monitor and document changes in the landscape and the built heritage – from coastal erosion to loss of architectural components in building. All this data provides additional information which feeds into conservation management decisions, allowing us to better preserve our wonderful cultural landscapes and heritage for future generations.

Opening up tricky spaces

Laser scan of underground mine showing the vertical access shaft leading to horizontal tunnel systems.

Alderley Edge: Laser scanning created this incredible walk through of a hidden cave system / © NT/ Christians Survey & Inspection Solutions

A cobalt mine, abandoned in the early 19th century, has recently been discovered and investigated at Alderley Edge in Cheshire revealing a ‘time capsule’ of personal objects and equipment the workers left behind. Laser scanning has enabled a virtual walk through of this incredible space to be created and shared - so now we can all explore it from the comfort of our own armchairs! National Trust archaeologist Jamie Lund says: "We are passionate about giving people the chance to explore our industrial heritage and the Derbyshire Caving Club conducts tours of some of the more accessible mines. But sometimes locations with impractical access mean we need to find other ways to bring the place to life for visitors. Virtual access is a great way anyone can navigate their way around the mine from the comfort of their armchair and imagine themselves in the boots of the men who worked there."

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