THE APPLICATION OF CLOSE RANGE PHOTOGRAMMETRY 
FOR ENGLISH HERITAGE CONSERVATION PROJECTS 
Paul G. Bryan BSc 
Metric Survey Team Leader and Head of the Photogrammetric Unit 
English Heritage 
37 Tanner Row, 
York, North Yorkshire, 
England YOl 6WP 
Tel +44 (0) 1904 601959 Fax +44 (0) 1904 601999 
email paul.bryan@english-heritage.org.uk 
UK National Delegate to CIPA 
KEY WORDS: Historic Environment, Conservation, Metric Survey, Photogrammetry, Digital Imaging, Specification 
ABSTRACT 
Within the UK, the term Metric Survey has now become a recognised element within any conservation project. However being a relatively 
new term for the collection of a base set of survey data, without any thematic enhancement, it does require further explanation and 
knowledge of how it can successfully fit into the typical management and documentation structure of a heritage project. 
The technology used to generate these data sets is of course rapidly developing. This brings new possibilities for the surveyor, the user of 
the data and, potentially, all associated with the project. However it also brings new challenges into how modem digital data sets can be 
successfully applied alongside other related data within a conservation context. The application of the digital image into photogrammetry is 
one such area that has seen rapid development in the last few years. This has resulted in digitally rectified and orthophotographic images 
now being regularly applied to both English Heritage and other UK based conservation projects alongside the more traditional vector based 
products. 
This paper aims to highlight some of the applications of close range photogrammetry made by English Heritage through the presentation of 
a number of example projects. These will include the previous work carried out on the standing stones at Stonehenge, the Whitby 
Headland area of North Yorkshire including the Abbey and most recently Ironbridge - the world's first ironbridge that became the symbol 
of the industrial revolution back in the 1780’s and is Britain’s best known industrial monument - where photogrammetry and other 
‘traditional’ survey techniques were combined with 3D laser scanning data for the first time within a real conservation project. 
1. INTRODUCTION 
It is a recognised fact that within any conservation project survey data will always be needed to inform the many processes 
undertaken. This fact was recently highlighted in a new English Heritage publication, ‘Informed Conservation’’ (English Heritage 
2001), which aims to provide guidance to conservation advisers on the techniques for understanding historic buildings and their 
landscapes, and specifically how to apply that understanding to conservation projects, through repair, alteration, development or 
management. Within this document the author highlights a very important fact that: 
‘ ....at the heart of any judgement about significance lies understanding. We need to know why, what is there is there. We 
need to know how it was constructed, altered and used through time; what survives and what has been lost. ’ 
Figure 1: Extracts from ‘Informed Conservation’ by Kate Clark, English Heritage 
This understanding can range from a rapid overview of the historic environment through to the detailed analysis of fabric, drawing 
upon all of the metric survey technology and expertise currently available. For this the author introduces us all to a new anachronym, 
CoBRA (Conservation Based Research and Analysis) which is explicitly defined as ‘the research, analysis, survey and investigation 
Proceedings 18 th International Symposium CIPA 2001 
Potsdam (Germany), September 18-21, 2001