Kemmelberg (Belgium) Case Study: Comparison of DTM Analysis Methods for the Detection of Relicts from the First World War

Laserscanning is a well known technology in a various range of scientific disciplines. This paper focuses on the manipulation of high resolution DTM's (Digital Terrain Models), to easily detect relicts in the landscape, dating from the First World War. Possible objects to detect are shell holes, trenches and other features related to the material remains of the First World War. A common method to detect these objects is the use of historical aerial photographs taken during this war (1914-1918). A database, containing relicts can be made, based on the interpretation of these images (remote sensing), possibly complimented by validation on site (fieldwalking). The interpretation of historical photographs requires thorough and specialized knowledge of the elements on these pictures. Stichelbaut (2009) has made a extensive research on the archaeological application of First World War aerial photographs in Flanders, Belgium. After the First World War, the existing landscape has totally been destroyed around the Mount Kemmel (municipality of Heuvelland, Belgium), and many war-related elements were removed during the reconstruction. However, in existing cases, elements are conserved, and still visible in the landscape. Some of these features still exist but the height difference with the surrounding surface is very small and therefore these features cannot be seen on site.

A thorough analysis of new aerial pictures will not always give satisfactory results in many cases. This paper focuses on the different technical filtertechniques to detect these objects. For example, this can be done by emphasizing the altitudes in a DTM, by the use of edge detectors. Different mathematical methods, using a convolution matrix, will be analyzed. The resulting data is a very important research tool for the cultural management of this fragile heritage.