he use of semi- 
ew technology 
lotogrammetric 
of photogram- 
| Architectural 
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cooperate and 
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ts reached are 
chitecture may 
from amateur 
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follows: Each 
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ter, the region 
. This way the 
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ated projects, 
tto Wagner's 
tz in Vienna, 
appears in an 
1 of the 150th 
  
A 6-station surveying network has been established 
around the building and the polar coordinates of 44 
(partly natural but well defined points, see examples of 
sketches, partly targetted by black stickers, 2cm diameter, 
cirular) control points have been measured. After the 
adjustment of the surveying measurements, the local 
cartesian coordinates of the control points have been 
determined with an rms values of 2mm. These points 
cover all four exterior facades. 
       
2,690 5,238 
Facade 2 (unscaled) 
28017 
A | m 
rs X 
Figure 2. Sample figure of the control points used in the test. 
Subsequently the object was photographically covered. 
During this campaign the following cameras have been 
used: 
* Rollei 6006 
* Hasselbland 500 EL/M 
* Leica Elcovision 
* Nikon FE2 
* Pentax PAMS 645P 
* Pentax ME-Super 
* Canon AE1 
* Contax RTS III 
* JVC-S77 camcorder 
totaling to more than 100 photographs. The scale of the 
images range from 1:200 to 1:400 for the medium format 
cameras and from 1:500 to 1:800 for the small format 
cameras. 
102 
E MEI 
i 
Do 
p 
zZ 
10510 ~. — 
[og ns 
wg 
106 9-7 
[706] — [1m] 
t 
d N 
107 
[107 ] ! Nm 
5 of] 
Figure 3. Sample figure of the photo configuration. 
The photographs have been measured by different 
measuring devices (analytical plotters, small analytical 
Systems, digitizers, automatic measurements on digital 
images) and the data processed by different software 
packages. 
3. THE PARTICIPANTS 
A network of 26 University Institutes of Photogrammetry 
in 16 mainly European countries has been formed. 12 
Universities have been working together on a project 
known as “Engineering Photogrammetry of CEI (Central 
European Initiative)” since 1991. The remaining 14 
Universities joined the group in 1992, at the request of 
CIPA. From those participants 16 Institutes have 
completed their contribution to the test, according to the 
following table. 
Three Pilot Centers have undertaken the job for 
administration of the test. More specifically, TUV 
(Vienna, Austria) is administrating the whole project, 
took the most of the photography and perfomed the 
surveying of the monument. AUT (Thessaloniki, Greece) 
undertook the analysis of the numerical results, and the 
statistics of compatibility of the different solutions. GRA 
(Granada, Spain) performed the analysis of the graphical 
presentations from the photogrammetric restitution. 
The participants were free to select the method and the 
instruments as available. 
4. DATA PROCESSING 
The participants work resulted in a total of 107 different 
solutions, using either semi- or non-metric camera, 
medium or small format, measuring devices of different 
accuracies, and minimum or maximum control. 
In order for all these solutions to be able to compare to 
each other the following strategy has been followed: 
4.1 Transformation to a common frame 
The minimum constrained solutions obtained so far have 
been transfered to the same reference frame which 
provides the minimum norm and it is defined by the free- 
network adjustment. The transformation of the minimum 
constrained solution to a free-network solution requires 
an S-(Helmert) transformation. The points kept fixed 
(base points) during this transformation are the same for 
all participants. The coordinates and the respective 
covariance matrix are then transferred to their free- 
network respectives. 
4.2 Accuracy assessment 
In order to access the accuracy of the adjusted 
coordinates we computed a number of criteria, ranging 
from local criteria to global criteria. It should be pointed 
out that all these are accuracy criteria since they refer to 
the actually known (from surveying measurements) object 
coordinates of the withheld from the adjustment check 
points. 
465 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B5. Vienna 1996