Ulrich MÜLLER / Alexandra KLINGELHÖFER, Jan-Martin HAFNER
(Büro für Ausgrabungen und Dokumentationen Heyse, Schwarzach am Main, Germany)

Keywords: 3D laser scan, GPS, EDM, medieval towns, urban archaeology

Laser Scanning in medieval towns of Nürnberg, Würzburg and Schweinfurt
During investigations in ancient cities of Southern Gemany by BfAD (Büro für Ausgrabungen und Dokumentationen Heyse) different types of laser scanning technologies were going to be used. The accurate documentation of architectural structures could be achieved by applying a FARO Focus 3D Laser Scanner. The integration of fixed points into the records enables the georefencing of the scanning result. The record may also be used to extract datas for CAD drawings and further processes. For more detailed information and also the documentation of finds an easy to handle Explius 3D Scanner approved to be a suitable tool. Both methods result in high resolution mapping and visualizing of archaological sites for presentation purposes.
In Würzburg the BfAD recorded the basement of “Platz’sche Garten”, once a noble dance hall, and “Gebhard’s Keller”, a ninepins alley with a taproom. Both locations had been situated near the medieval town centre and were destroyed by bombs during the Second World War. After the bombing the still intact cellar system remained untouched for decades and had then be recovered and documented. Parts of the basement functioned as an air-raid shelter and showed precautions written on the wall which are clearly visible in the scan record. The laser mapping of the basement and the reference points allowed a total 3D reconstruction. Through processing the datas with AutoCAD software different isometric views could be produced. The records were georeferenced with a total station on the surface. During comparable investigations, e.g. in Nürnberg and Schweinfurt, the fixed points have been produced by using a GPS. High accuracy of the measurements could be reached with correction datas of the mobile provider. The result of combining the applied methods offers different advantages and fulfills several requirements of correct documentation.