Background

Mousa Broch is a Iron Age structure in the Shetland Islands, now maintained by Historic Scotland who requested a survey for the purpose of measuring deformation within the walls. The laser scanner provides the accuracy to accomplish this within 6mm.

Task

Accessing the site is a challenge in itself, the scanner has a field of view of about 40 degrees, side to side and top to bottom. For this structure it was best to have the scanner back far enough to capture the height within its field of view. However this was a problematic as one side of the Broch is located relatively close to water, extra scans were required on this side to gain complete coverage of the broch.

Output

The output from the Mousa survey consisted of elevations, incremental plan profiles, a mesh model and a fly-through animation. The elevations were created every 9 degrees, yielding a total of 40 of the 14 metre high broch. 18 profiles were taken at intervals of either 1.0 metre or 0.5 metre. The combination of the elevation and plan information combined with pictorial aspects of the mesh model produced a data set that may be re-created in the field in order to monitor the structure over time.

© Copyright - Mason - 2005