The nature of the interior above the levels of the oil lamps 
in both chambers could only be seen when halogen lamps 
were brought inside. The ceilings in both chambers were 
then revealed as domed and caked with soot; an interior 
cupola, supported by columns above the top level of the 
marble wall coverings, was brought to light in the Tomb 
Chamber. : 
Confronted by such complex shapes and ornamentation in 
confined spaces, it was decided that only a superficial 
record of the interiors could be made in the time available. 
Moreover it would have been most inappropriate to leave 
any targets on the walls, so the control survey was quickly 
extended into (but not out of) both chambers by electronic 
tacheometry. Taped distances in many combinations 
between the survey stations inside and the targets were 
made. Photographs were taken with the UMK and then all 
evidence removed during one energetic two-hour spell on 
one of the two nights when the team was allowed to remain 
in the Church after the closing ceremony at 20.00h. 
Occupation of the Edicule was shared with the occasional 
pilgrim and other members of the team making 
archaeological records of inscriptions and ornaments and 
taking photographs for descriptive purposes. 
All 40 Avipan plates were processed at night in a hostel 
bathroom using a specially prepared plate processing tank. 
Ilford ID11 developer was selected because it was easily 
transported in powder form, and its dilution could be 
varied for tonal control of the Agfa plates used. By 
processing the plates daily it was possible to design 
lighting, exposure and processing so that detail was 
adequately recorded. 
Computations of some of the main elements of the control 
survey were carried out as the survey progressed to check 
that they contained no gross errors. About 450 
measurements were recorded on the MEM module of the 
Tachymat (the least number personally recorded over 
several days’ observations!). 
3.2.11 -27 April 1990, 
The second visit was for a longer period because of the 
need to do much more work inside the Edicule than 
outside. It was not known beforehand whether permission 
would be given for working at night. In the event no work 
took place before Easter, but for 7 days and 6 nights 
between 16 and 25 April work was undertaken. 
All 8 external survey stations used in 1989 were re-located 
and found by check measurements to be in position. A site 
grid was set out for a hand survey of the floor of the 
Rotunda. This grid was in the same coordinate system as 
that used for the control survey. The first major task was 
to extend the control survey into the Edicule and out again, 
preferably by a different route. The Chapel of the Angel 
and the Tomb Chamber each had a cowled hole in the roof 
(Fig.1) to let out smoke from the oil lamps. It was possible 
to use the tacheometer on a trivet set over a floor station 
to sight and measure to a mini-prism vertically above 
through each smoke hole. A diagonal eyepiece was used. 
Other holes, used for passing out flames during the Greek 
Orthodox Ceremony of the Holy Fire on Easter Saturday, 
ran through the meter-thick walls of the Chapel of the 
Angel . It was not possible to measure with EDM through 
these holes because they were too long and narrow, but 
sightings were made through to give a third connection 
between internal and external stations. Five new 
instrument stations were used, two on the floor of the 
Rotunda, two inside the Edicule and one on the roof. 
The intention in 1990 was to complete the photography of 
the exterior by a few fill-in stereopairs but most 
importantly to obtain as complete a record as possible of 
the complex and confined interior spaces, including the 
two internal domes above the levels of the hanging oil 
lamps. A Hassleblad SWC with Zeiss Biogon lens had 
been modified at the Engineering Surveying Research 
Centre by the incorporation of a 100 point reseau grid plate 
and by pinning the lens to give a stable lens cone for sharp 
images of objects from 1.2m to infinity at f/22. A T-shaped 
mono-pod mount for the camera/flash combination was 
produced. The length of the vertical stem could be varied 
from about 0.5m to 2.5m. The short horizontal arm had a 
mount for flash at its centre. The camera could be attached 
to either end of the horizontal arm, so that the lighting 
arrangement remained constant for each stereopair. The 
mount with camera and flash attached was poked up 
through the burning oil lamps so that photographs of the 
domes could be obtained. A series of sight holes in the 
vertical stem of the monopod and a small level bubble 
allowed approximate setting of the camera exterior 
orientation for each exposure. Photographs could also be 
Table 1. Some statistics from the bundle adjustment. 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
No. of cameras 6 
No. of photographs 196 
No. of ext. or. parameters 1176 
No. of object points 414 
No. of object pt. coordinates 1242 
Total no. of unknown 2418 
params. 
No. of constraints needed 4 
No. of survey measurements 996 
No of measured photocoords. 5894 
Total no. of measurements 6890 
No. of degrees of freedom 4476 
A priori std. dev. angles 0.01 
A priori std. dev. distances ] to 10 mm 
Se 010 125m 
A posteriori rms std. dev. X 3.5mm 
A posteriori rms std. dev. Y 3.6mm 
A posteriori rms std. dev. Z 4.4mm 
A posteriori max std dev X 19.6mm* 
A posteriori max std dev. Y 19.2mm* 
A posteriori max std dev. Z 33. 1mm* 
* For natural features which are imaged on only two 
photographs. Only 20 points have coordinate standard 
deviations greater than 10mm.