CIPA 2003 XIX th International Symposium, 30 September-04 October, 2003, Antalya, Turkey 
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fig.l Graphical elaboration of some photogrammetric surveys done in S. Marco Square: the block paving of the square (1997) and 
of Loggetta (1996) 
executed by architects; these professionals have studied at 
length the expressive possibilities and use of survey. 
Close range survey 
Several close range survey techniques were experimented on 
buildings around the Square. The most interesting and 
contemporary are photogrammetric survey (that has a long 
tradition, although in recent years it has been augmented by 
digital photogrammetry and image processing) and laser 
scanner survey. 
In the past ten years, almost all the buildings present in the St. 
Mark's area have been surveyed by the more important public 
and private bodies in the sector in Italy, with excellent results 
considering the most established and proven photogrammetric 
methods were used (fig. 1). 
Laser scanning is still being tested, not only as regards several 
aspects of the instrument, such as the characteristics of accuracy 
of the sensors, but especially for possible methods of 
application and the possibilities of processing: 
• configuration of the scanning around the object; 
• alignment of the clouds; 
• noise filtering; 
• decimation of the points; 
• meshing; 
• automatic recognition of primitive solids. 
As regards the first two points, one contribution could entail 
making the instrument more topographical, by making the 
primary axis vertical; in this way, the degree of freedom of the 
clouds is reduced by passing from 6/7 to 4 as in the 3D 
topographical mesh. 
At the state of the art, alignment of the clouds is made quite 
efficiently by techniques comparable to the ones used by aerial 
triangulation to independent models (Forlani 2003, Lingua 
2003).