DOCUMENTATION OF ARCHAEOLOGICAL RUINS AND STANDING MONUMENTS 
USING PHOTO-RECTIFICATION AND 3D MODELLING. 
F. Summers ^ *, N. Atalan a , N. Aydm a , O. Baraga? a , G. Ugar 2 
a The Kerkenes Project, Faculty of Architecture, Middle East Technical University, Ankara, Turkey - 
fsummers@metu.edu.tr, natalan@isbank.net.tr, ozge@metu.edu.tr, gulnurucar@yahoo.com. 
KEY WORDS: Archaeology, Cultural Heritage, Photogrammetry, Photo-rectification, G1S, 3D Modelling, Digital Photography, 
Virtual Reality. 
ABSTRACT: 
Photo-rectification and 3D modelling offer a wide range of methods for the study and presentation, to a variety of audiences, of both 
urban features and standing monuments at archaeological sites. Ever more powerful software and hardware are continually pushing 
forward the limits of performance while electronic publication, on CD-Rom and through the World Wide Web, allows quick and 
easy dissemination of results. This paper presents a study at the METU Faculty of Architecture, made possible by a METU research 
grant (AFP2000), in which staff and students worked on different techniques for recording and surveying urban and architectural 
elements and reconstituting them in a virtual environment. The studies include examples from Kerkenes, a large Iron Age city in 
Central Anatolia, where well-preserved elements of defensive stone structures together with extensive stone paving were revealed, a 
portion of the standing Byzantine to Ottoman walls at Ankara Kale and, finally, multi-period remains of Napoleonic to WWII 
defences located on a small islet off the south-east coast of Mauritius. Software employed are (i) AERIAL, a simple rectification 
program designed for non-experts working on desktop computers, (ii) PhotoModeler and (iii) GIS (Geographical Information 
System) software, including ArcView and ERDAS Imaging. These studies have made considerable and significant progress towards 
demonstrating the potential of IT (Information Technology) and GIS tools in the study of architectural and urban elements within 
both the historical and the present environment. The methods and techniques could equally well be used to make visual projections 
of active and intrusive architectural conservation and restoration programs. 
1. INTRODUCTION 
New software and improvement in hardware continually push 
forward the limits of performance in the application of photo 
rectification and 3D modelling. Electronic publication of 
results, on CD-Rom and through the World Wide Web, allows 
for rapid and easy dissemination of results. The aim of these 
studies, conducted on a wide variety of projects, was the 
development of techniques in photo-rectification and 3D 
modelling that would have a broad range of applications in both 
urban and architectural studies. The Kerkenes Project team has 
pioneered employment and collation of several different 
methods for surveying, recording and analysing urban elements. 
Recent results show that Information Technology provides 
numerous, continually developing, tools which the city planner 
and the architect can use in studies of the built environment, be 
it historical or contemporary. Examples have been taken from 
several ongoing projects concerned with archaeological, urban, 
architectural and environmental studies. The project has 
focussed on: 
1. The use of various techniques for recording and 
surveying urban and architectural elements, both historical 
and contemporary; 
2. The representation of data and results in a virtual 
environment; 
3. Virtual reconstitution of urban and architectural 
elements within the areas of study; 
4. Traditional and electronic publication of the results. 
2. SURVEY AND RECORDING TECHNIQUES 
2.1 Plans and Elevations of Stone Walls 
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Figure 1. Rectified photographs are imported into AutoCad and 
cropped to form a photo-mosaic of the wall elevation. 
Stone walls are tedious to record when accurate scale drawings 
that show each stone are required. Digital photography and 
rectification can greatly reduce time expended on detailed 
recording in the field. One example chosen for this study was a 
stretch of walling (Fig. 1) revealed by a machine dug trench at 
the bottom of the Kerkenes Dag to tap water to the village of 
$ahmurath. This feature, perhaps of historical value, was 
exposed only for a short time and working conditions were 
difficult. Rectification with AERIAL 5.3 involves creating over 
the wall surface a net of control points marked with chalk, 
paper or in some other suitable way. Strings can also be used to 
mark the triangles formed within the net. In cases where the 
surface comprises a combination of different planes it is 
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