The first use of 3D laser scanning at Stonehenge was of the

Bronze Age The Bronze Age () was a historical period characterised principally by the use of bronze tools and the development of complex urban societies, as well as the adoption of writing in some areas. The Bronze Age is the middle principal period of ...

dagger and axes inscribed on the

sarsen Sarsen stones are silicification, silicified sandstone blocks found extensively across southern England on the Salisbury Plain and the Marlborough Downs in Wiltshire; in Kent; and in smaller quantities in Berkshire, Essex, Oxfordshire, Dorset, an ...

s, which was undertaken in 2002 by a team from Wessex Archaeology and Archaeoptics. They used a

Minolta was a Japanese manufacturer of cameras, lenses, camera accessories, photocopiers, fax machines, and laser printers. Minolta Co., Ltd., which is also known simply as Minolta, was founded in Osaka, Japan, in 1928 as . It made the first integrated ...

Vivid 900 scanner to analyse and record surfaces of the

prehistoric Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use o ...

and post-medieval carvings. The

carvings of a

dagger A dagger is a fighting knife with a very sharp point and usually one or two sharp edges, typically designed or capable of being used as a cutting or stabbing, thrusting weapon.State v. Martin, 633 S.W.2d 80 (Mo. 1982): This is the dictionary or ...

and an axehead were first discovered by

archaeologist Archaeology or archeology is the study of human activity through the recovery and analysis of material culture. The archaeological record consists of Artifact (archaeology), artifacts, architecture, biofact (archaeology), biofacts or ecofacts, ...

Richard J. C. Atkinson in 1953 on stone number 53, one of the imposing

trilithon A trilithon or trilith is a structure consisting of two large vertical stones (posts) supporting a third stone set horizontally across the top ( lintel). It is commonly used in the context of megalithic monuments. The most famous trilithons a ...

s. A contemporary survey in 1956 by Robert Newall revealed that the total number of axes on this stone totalled 14, all on the same face of the stone, looking inwards to the centre of the stone circle. Typologically, the axes have a Middle

date. The surface of stone 53 containing

carvings was laser scanned at a resolution of 0.5mm, resulting in hundreds of thousands of individual 3D measurements known as a

point cloud A point cloud is a discrete set of data Point (geometry), points in space. The points may represent a 3D shape or object. Each point Position (geometry), position has its set of Cartesian coordinates (X, Y, Z). Points may contain data other than ...

. These data were then processed into a meshed 3D solid model for analysis using custom software written by Archaeoptics called ''Demon3D''. The team pioneered some visualisation techniques to enhance the outlines of the known carvings. During this process, the faint outline of two previously unknown axes was spotted in an animation, separate from the carvings recorded by Newall. Subsequent enhancement of the data confirmed that the shapes were of

flange A flange is a protruded ridge, lip or rim (wheel), rim, either external or internal, that serves to increase shear strength, strength (as the flange of a steel beam (structure), beam such as an I-beam or a T-beam); for easy attachment/transfer o ...

d axes, similar in shape to those clearly visible, but either badly

eroded Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust and then transports it to another location where it is deposited. Erosion is disti ...

, or were originally carved much shallower than their counterparts. The larger of the two carvings differs slightly from the other axes in that it has two 'lugs' along its shaft, and others have interpreted that it could represent either an axe, a mushroom, or a ram's skull. The results of these investigations were published in an article entitled "The Stonehenge Laser Show" in the November 2003 edition of

British Archaeology The Council for British Archaeology (CBA) is an educational charity established in 1944 in the UK. It works to involve people in archaeology and to promote the appreciation and care of the historic environment for the benefit of present and fut ...

. In 2011 English Heritage commissioned a full laser scan of the visible faces of all stones as Stonehenge in high resolution (sub-millimetre), as well as a lower resolution scan of the ground in the area known as the "Stonehenge Triangle".

References

External links

*https://web.archive.org/web/20051225111736/http://www.stonehengelaserscan.org/ {{Stonehenge Stonehenge