Exploring the use of 3D GIS as an analytical tool in archaeological excavation practice

Abstract: Several digital technologies are now available to record and document archaeological excavations. A large number of studies have been published concerning the use of laser scanning, image based 3D modelling and GIS. By integrating different typologies of 3D data from Uppåkra, an Iron Age central place in southern Sweden, this thesis focuses on the development and evaluation of how 3D Geographic Information Systems (3D GIS) affect archaeological practice. In specific a Digital Terrain Model (DTM) was created for the site and the surrounding landscape. A UAV (drone) was used to document the excavation area in higher resolution, and image based 3D modelling was used to record the ongoing excavation on a single-context level. These different typologies of data were subsequently imported in a 3D GIS system (ArcScene) in order to conduct various types of spatial analysis (e.g. hillshade and slope analysis) as well as to create 3D drawings of the excavated contexts, using the textured 3D models as a geometrical reference. The ability to virtually revisit previous stages of the excavation and the use of tablet PC’s for documentation and discussion at the trowel’s edge increased reflexivity on the excavation and stimulated on-site interpretation by the excavation team. The model based drawing approach furthermore improved the drawing resolution compared to traditional documentation using a total station, especially for complicated contexts. This approach allowed connecting different typologies of data in the same virtual space, 1) increasing the possibility of researchers and scholars to gain a complete overview of all the information available, as well as 2) exponentially increasing the possibilities to perform new analysis. The ability to interact and navigate with all the data in 3D improved the impact of the data and comes closer to simulating the real world. Though some challenges still have to be faced, such as inaccurate georeferencing and unrealistic colour projection, the method was found to significantly improve the documentation quality by creating a multi-scale 3D documentation platform. By further developing this method, it can help us to improve the standards of archaeological excavation documentation.