Geospatial technology uncovers Prehistoric Artwork at Stonehenge
Geospatial technology was used to visualise and analyse the most detailed laser-scan survey ever conducted at Stonehenge. The laser scan used a point spacing of 0.5 millimeters to get high resolution results which revealed important information for analysis.
ArcHeritage, part of the United Kingdom’s York Archaeological Trust, is examining this ancient structure as part of a English Heritage-commissioned project. Preliminary analyses of the meshed models identified individual tool marks more than 5,000 years old, but the data contained additional prehistoric artwork carved onto the stones’ surfaces, so the team decided to visualise the original point-cloud data.
Bentley Systems Inc.’s Bentley Pointools enabled large datasets to be loaded, facilitating an examination of full-resolution data. The software’s shading function was instrumental in visualising the most subtle features, which resulted in the discovery of 71 carvings of Bronze Age axes not seen in more than 3,000 years.
Depending on the position in relation to a preset camera plane, each data point was assigned a grayscale value, allowing subtle features to be visible. When the images were combined into an animation and played back, the carvings, which are invisible to the naked eye, are seen fading in and out. After the carvings’ extent was identified, the team deployed measuring and point-location tools to accurately plot the carvings to an Ordnance Survey grid.
Further information about the laser-scan survey results can be found on the ArcHeritage's website.