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excluded, i.e. those where comparison was not 
possible. 
A vectorial diagram was also traced 
in which each vector indicates the differences 
between the examined and reference phases. 
From these results it was noted that the maximum 
vertical displacement was 16.6 mm reached during 
phase 30 (figure 2). 
Another processing was carried out in order to 
control the platform's tensional level. For this, 
the points were subjected to rigid 
rototranslation, i.e. maintaining the reciprocal 
distances in order to minimise the deviations. 
The result obtained was that of greatly reducing 
the size of the deviations passind to a maximum 
value of 6 mm. It was thus assumed that the 
deformations were mainly due to rigid movements of 
the structure and so the tensional state of the 
elements were not increased greatly during the 
loading operation. 
7. CONCLUSIONS 
The survey results showed that the structure 
undergoes small stresses. So, from a structural 
point of view, the jacket had no problem during 
the load out. 
The photogrammetric survey gave good results in 
terms of accuracy and quantity of data. 
Stereophotogrammetry was tested in detail in 
shipyard surveys and did not create special 
problems even although it was used in very bad 
environmental conditions with little nightime 
light and the shooting had to be carried out in 
very limited times. 
The survey could not have been carried out using 
any other method because the topographic measuring 
requires times which would have been unacceptable. 
One possible adjustment to allow a better 
structural analysis could be to evaluate the 
lowering of the boundaries ie. the launching beam 
and the boat by geometric levelling. 
The main result is undoubleddly that of having 
verified the possibility of using 
stereophotogrammetry to measure large structures 
which may even be in movement. 
This method also gives results in a very simple 
form which may be processed for other aims such as 
structural analysis or CAD representation. 
8. ACKNOWLEDGMENTS 
The author expresses his gratitude to Agip for its 
permission to publish this report. Many thanks 
also to colleagues from Industrial Photogrammetry 
for the cooperation given during the survey and to 
colleagues from the EDPI group for designing the 
data processing programs. 
Finally, special thanks also go to the Intermare 
yard at Arbatax (Italy) for its cooperation during 
the survey. 
9. BIBLIOGRAPHY 
References from BOOKS: 
American Society of Photogrammetry, 1989. 
Handbook of non-topographic photogrammetry. XI 
Edition, pp. 349-356 
References from JOURNAL 
G. Bozzolato 1988. A new photogrammetric 
procedure for offshore engineering surveys. The 
photogrammetric record. 13(74): 277-287 
References from GREY LITERATURE: 
M. Rampolli, E. Bonora, 1990. CAD system use for 
photogrammetric measurements of Agip's offshore 
structures. In: Int. Arch.  Photogramm. Remote 
Sensing. Zurich Switzerland, pp. 349-362 
M. Rampolli, 1990. Dimensional verification to be 
carriede out at open sea on offshore structures by 
means of photogrammetry. Int. Arch. The 
European Oil and gas Conference.SER. 
Palermo-Italy, p.409