3D IMAGE BASED GEOMETRIC DOCUMENTATION OF A MEDIEVAL FORTRESS

Abstract. The detailed and thorough documentation of monuments is a rather complex process that requires the application of the best available state of the art techniques in order to preserve, restore, promote and make cultural heritage accessible to the public. This paper presents the 3D Geometric Documentation of a part of the medieval fortress of Chios, focussing in particular on the practical challenges which the object presented. The case study is a part of the fortified construction, consisting of a bastion, a watch tower on top of this bastion and a significant part of its walls with a surface of about 1053 m 2 in total. The goal of the survey was to produce an accurate 3D detailed textured model and a series of coloured orthophotos and 2D vector drawings. The documentation methods employed included close-range automated photogrammetry and image-based modelling, terrestrial laser scanning and topographic surveys, an ideal combination of methods.