Bluetooth’s fortresses, machine learning and meteor craters?

The Trelleborg viking fortresses are an important expression of power and control relating to the formation of the early medieval kingdom of Denmark. The systematic placement of and spacing between the five known examples suggests that there may be further, as yet undiscovered examples. Additionally, these features superfically resemble meteor impact craters. Could we find these features?

a) Known viking fortresses (dark blue dots), towns (hollow blue dots) and new candidates (light blue dots), with examples of appearence of the known viking age ring fortresses

We tested this by using a combination of computer vision and machine learning techniques using national coverage lidar data in conjunction with historic mapping. This identified two fortresses that we think are worth a closer look, and nothing that looks like a meteor crater.

False positives

For a full description of this project please see our paper:

Workflow used in the study