Automatic graves' orientation detection: A tool for spatial archeology

The assessment of the preferred orientation of graves in a necropolis represents an interesting contribution to the study of a civilization. In this paper two different methods are presented. The first one implies a parameterization of the map, i.e. its manual translation into a shapefile, where each grave of the necropolis is separately analyzed and a subsequent automatic orientation of the whole necropolis is achieved. This method proved to be highly reliable in the determining the tomb orientation and entrance direction, although it was quite time consuming, since a fairly important amount of manual work was required. On the other hand, the alternative proposed method using the Radon transform proved to be able to assess the main direction of the whole necropolis analyzing the scanned map image, in a fast and reliable way, without the need of any manual intervention. However in the simplest implementation and for the entire image at once, with the Radon transform it is not possible to determine the versus of the located lines. This is instead achievable when analyzing the single graves. In both cases, the main orientation was correctly detected.