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3. CASE STUDY 2: TYNEMOUTH PRIORY 
3.1. The Tynemouth Priory site 
The site at Tynemouth has been an important religious centre 
and coastal fortification from the Seventh Century up until the 
present day. Two saints are buried within the walls of the 
Priory and two walls of the presbytery still stand to their full 
height of 22m (Hadcock, 1991). A small structure on the 
Priory site, the Prior’s Hall (Figure 5), was selected to be 
scanned using a Cyrax 2500 laser scanner. The Prior’s Hall 
was originally used to entertain the guests of the Prior and has 
undergone a complex process of development throughout its 
history, making it, as with Ashby castle, typical of many 
historic structures in the United Kingdom. Initially thought to 
be built around 1090-1140 it has seen structural additions and 
alterations in both the 13 th and 14 lh Century. Interpretation of 
this development would be aided by accurate and complete 
survey data helping to improve the appreciation of the structure 
and, therefore, understanding of the building’s significance. 
Additionally, recording areas of deterioration helps plan for 
maintenance work and determine the safety of the structure as it 
is fully accessible to the public. 
PÜr 
Profile 
Profile 2 
Figure 5. Priors Hall, Tynemouth Priory. The profiles collected 
using the laser scan and photogrammetric data are highlighted. 
3.2. Laser scanning 
Scanning was performed using a Cyrax 2500 scanner. This is 
also a time-of-flight system but has a quoted accuracy of 6mm - 
higher than Riegl LMS Z210. It has a highly collimated laser 
spot giving a footprint of 6mm at 50 metres (Cyra, 2002). As 
with the Riegl scanner the progress of the current scan is shown 
via the scanner software, although, unlike the Riegl system the 
Cyclone software shows the data being collected in an 
interactive 3D view - it was found that this allowed a fuller 
inspection of the areas being scanned. The Cyclone software is 
also the tool used to process the scan data and export it to CAD 
packages as required. 
In this survey the main aim was a full record of the Prior’s Hall 
referenced to the established local site grid. Three scans were 
used to record three of the four main aspects of the building 
consisting in total of approximately 690 000 scanned points. 
Overlapping areas of scan data were not required as the 
positions of the reflective targets used for registration were 
known. However, some overlap was made between scans to 
allow the efficient use of the targeted points (reducing the 
number of control points required) and improving the 
redundancy of the registration. It would have been preferable 
to complete the loop around the building, scanning all four 
aspects, to increase the strength of the registration; however, 
restrictions on site time did not allow this. In total, seven green 
reflective targets were used and were coordinated on the local 
site grid by intersection observations from at least two control 
points using a total station. At least four of the targets were 
present in each scan. The scanning and accompanying survey 
work took one day which includes the registration of the scans 
to the local site grid. 
3.3. Photogrammetry 
Conventional close range photogrammetry has been performed 
on the hall in a previous research project (Mills et al., 2000) and 
followed the standard English Heritage photogrammetric 
survey specification (Bryan and Blake, 2000) producing a line 
drawing at a standard plotting scale of 1:50 using a Zeiss P3 
photogrammetric plotter. The imagery used to produce this 
drawing has also been used in SOCET SET to produce 
orthorectified photography and profiles. 
3.4. Profiles 
Figure 6 shows profiles manually collected using SOCET SET 
and extracted from the point cloud. The correlation coefficient 
for the profiles was 0.96 and 0.89 for profiles one and two 
respectively. As with Ashby Castle the profiles were broken in 
some areas due to shadow. 
6.6m 
Figure 6. Profiles one (left) and two (right) from Priors Hall.