78
equipment like a graduate tape, donbie meter . plumb
line, square.
The figure n°2 shows the result of this work at 1:50 scale.
Fig. 2 - Planimetric survey of the church
The prospects photogram metrical survey
For what it concerns the terrestrial photogrammetrical
survey of Marmashen we realised different kinds
photogramms . following the method to be adopted in the
restitution phase, and in relation to the inner
characteristics of the various prospectsand of the specific
environmental situation (exposition, facing space,
different encumbrances, etc.)
For example the main façade (fig.3) that for the ruin
state, needed a more accurate survey, which was only
possible with the classical photogrammetry. has been
surveyed with couples of photogramms made with the
ZEISS TMK6 camera with a 60 mm focus and formed
with photogrammes of about 8x11 cm 2 .
Fig. 3 - The main façade of Marmashen church
Talking about the taking of photogramms regarding this
monument section, the topographical conditions and the
façade size have determined the necessity to install a
scaffolding that made possible the taking place of the
photogramms taking at about 3.50 metres high.
The determination of support points took place in
applying the topographical method of the simple forward
intersection.
Every model has been restituted on the basis of pre
signalled coordinates points (at least 5 for every model)
obtained by the angular measures took with the Wild T2
teodolitc.
For the restitution we used the WILD BC3 analitic
stereorestitutor consisting in a restitution device and in a
computer system with its different parts.
The computer is installed on a special projected desk
provided with all the peripheral equipment.
The standard configuration includes a high resolution
graphic monitor with 256 colors and a mouse with three
keys.
The base unity for the restitution is installed on a special
table containing the optical and mechanical components
necessary to observe the photogrammes and to move the
trolley on which they are settled and a computer checking
the restitution process.
The software is able to explore the image points of the
model calculating mathematically the coordinates of
every correspondent object point.
The different restitution phases are visualised in real time
on a high definition graphic monitor and can be easily
managed by an articulate "multiple-window" menu.
Beginning from photogrammes couples, obtained by the
already mentioned metric camera and by numerical files
containing the support points coordinates located on the
object as already stated too, we obtained a three-
dimensional optic model that itself can be restituted in
numerical or graphic data using output on monitor,
printer, plotter, floppy disk.
Using this method it was possible to obtain high level
results in the three dimension for w'hat it concerns the
precision (the mistake is in fact equal or inferior than the
graphificism error of the chosen representation scale,
related to the photogrammes scale) (fig.4).
Fig. 4 -The west prospect of Marmashen church
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