Viking ring forts

Amazingly the danish government has provided open access to lidar survey of the entire country. Of course, I was really hoping to be able to model the Danevirke, but despite the name (and its original function) that now all lies within Germany. However the Viking ring fortresses are rather nice. Here the Aggersborg, Fyrkat and Trelleborg, and below the Aggersborg in 3D.

Only five examples of such fortresses are known in Denmark. The Nonnebakken fortress at Odense disappeared beneath the town in the 19th century. The ploughed out remains of a fifth, the Borrering, were long suspected but only recently dated (and not really as 'newly discovered' as some news reports/press releases would have you believe!).

Burrough Hill Lidar

I was surprised to see EA data at 0.5m centres available for this seemingly random block of Leicestershire countryside until I noticed this. So presumably this derives from the survey commissioned by the University of Leicester, although point density may have been somewhat higher in the original surveys to judge by that nice de-vegetated bare-earth model. Pleasing results from this nonetheless.

The first image is a slope severity plot; the perspective view from the south-west is based on a sky-view factor plot.