CIPA 2003 XIXInternational Symposium, 30 September - 04 October, 2003, Antalya, Turkey 
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Fig. 1.8 Top view of the "very low altitude photography crew" 
Fig. 1.9 Part of a 2D-Photomap of the historic site of the Jewish 
Cemetery in Magdeburg (Germany) 
2. New Perspectives for Processing Single Images in 
Conservation. 
It is liked to point out, the signalization of controlpoints partly 
can be replaced by (digital) photographs of the queue of ground 
survey points, when engaged with the reflectorstaff. These 
controlpoints, can be clearly interpreted on the snapshot and 
transferred to the corresponding synoptic photograph for, e.g., 
rectification purposes. It is also very important, clearly to assign 
the point number on the picture, at least by voice recording for 
moving sequences. 
The use of single images in conservation can benefit from 
existing digital imageprocessing devices and suited software, as 
well as (still?) from analog rectification devices. For low 
attitude values the latter even could be overhead or slide 
projectors. 
A new way to visualize the projection theory can be derived 
from the French facet method. The facet method has been used 
in France until about 1970 in an analogue manner, even for 
precisely cadastral mapping purposes. The characteristic terrain 
surface is adapted by multiple polyeder projection. 
For a modem flexible application of a modified facet method, in 
particular to survey an Archaeological site, the “polyeder” can 
show a regularly (4 x 4m) grid as well as random edges, see 
Fig. 2.1 
- The edges of these polyeder pattern are marked with wooden 
colored sticks. 
- The object surface must be suited to be adapted by a polyeder 
pattern 
- The three dimensional coordinates of the regular or non 
regular situated edges of the polyeder pattern are set out and/or 
determined using the conventional terrestrial polar surveying 
method. 
- Extremely low altitude aerial photography, successive taken 
with a amateur camera from a telescope beam of approximately 
10m height, must show the particular polyeder or grid plain of 
about 4 x 4 m in nature, as indicated by at least 4 corresponding 
marked points of the polyeder respectively of the grid. 
The exposure is verified from the ground using modem 
infrared control or ball exposure. 
Continuously the images, defining the polyeder, will be 
digitized and digitally rectified, based on at least 4 
controlpoints, e.g., using the Rollei MSR rectification 
program. 
Of course an alternate method is analog optical 
rectification using a rectifier. 
Finally the rectified images are digitally or manually 
mosaiced to achieve the complete 
Fig. 2.1 Principle sketch of the modified facet method for 
obtaining a rectified photo mosaic by approximating the object 
surface with a regular and/or non regular grid pattern and 
successive processing of digital or analog image rectifications 
Fig. 2.2 Differentiell rectified Orthophoto of the excavating 
situation in 2001, based on the principle of the facet method 
(see fig. 2.1), as carried out by B. Luebbehusen, who mosaiced 
about 80 rectified single images showing a 4 x 4 m grid