ci PA 2003 XIX th International Symposium, 30 September-04 October, 2003, Antalya, Turkey 
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- a detailed survey of the external surfaces. We have to remember 
that there are a lot of irregular conditions due to static problems, 
materials decay and binding transfonnations, so, an accurate choice 
of the points have been projected (Figure 8); 
- a direct survey, using a diastimeter, of the interior, linked to the 
points on the openings, measured with a total station; 
- the acquisition of control points aimed at image rectification of 
the facades. The survey of details and of the control points has 
been done using a reflectorless total station Leica TCR703; 
- a photo campaign with a semimetric Rollei 6006 camera (f=40 mm). 
6.1 Stratigraphic survey 
This is a method taken from archeology with the difference that 
in architecture it is linked to the observation of what is visible; 
it is not a destructive analysis as in excavation. It consists of the 
annotation, on a graphic representation, of all building events, to 
Figure 10. An example of digital image rectification; 
on the left are visible the used control points. 
reconstruct its transformations through the exam of technical and 
morphological features of its elements. It is important to arrange 
a system of graphic conventions to show the principal events. 
It generally needs a bidimensional graphic support and, if the 
object of study is planary enough, image rectification is an exellent 
support to annote the observations (Figures 10,13). 
So it is possible to highlight, directly on the image, the 
stratigraphic units intended as a product of an omogeneous 
constructive action, positive or negative, on the analyzed wall. 
A single unit is characterized by surface, contour, volume, each 
having its specifications. Particular attention is given to the edges, 
elevations, openings, materials, finishings, processing. The aim 
Figure 12. Stratigraphic survey on the north and west facades 
around the court. At the numbers are linked specifications on 
the single unit while different colors make a synthesis of most 
important constructive phases. Under them an example of 
matrix gives a stratigraphic sequence. 
is to establish different layers in chronological sequences, and 
constructive actions were put in phases. It follows a Matrix (Harris) 
that shows the stratigraphic relations; it is really a work tool, the 
base on which interpretations can be carried out (Figure 12). To 
obtain an absolute dating it is necessary to refer either to historic 
documents or to direct sources: there are, for example, two types 
Figure 11. An example of stratigraphic survey on a facade; 
hypothesis of chronological reconstruction of the Povil Casaforte. 
Figure 13. The stratigraphy on the rectified image allows to see 
underlyng wall texture; 
of windows in our case: the first one is a loop-hole, the original 
openings, the second one, richer and decorated, is the evidence of 
a transformation in a civil building. Also wall textures have been 
classified by taking a sample (1 mx 1 m). 
Vectorial data has been directly drafted from rectified images but 
it is also possible to represent them on the raster image, modifying 
colors or contrast to make visible the underlying texture. Another 
step can be to use a 3D model to show critical situations where 
the spatial continuity is important, for example, the edges or the 
relation between plan and elevations.