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.
