preparation of environmental cartography and realization of
data banks and agroclimatology.
Therefore, the Academy, in addition to being an institution that
keeps historical archives, it is also a promotional centre of
enterprises and research in order to face and solve the
problems in the agricultural field.
4. THE PROJECT REALIZATION
In order to prepare a technical documentation of the damages
caused by the explosion in Via Georgofili, a tridimensional
numerical photogrammetric survey of the area was made. The
boundaries on four sides were Via Castellani, the Arno river,
Via Por Santa Maria and Piazza Signoria.
The project included two distinct surveys: one made use of
terrestrial photographs taken at the base of the Pulci tower; the
other included aerial photographs over the area of attack.
For the terrestrial survey, two pairs of overlapping photographs
of the southern wall of the Pulci tower were taken.Spatial local
coordinates of eight points on the same wall were determined
by a conventional theodolite in order to control the geometry of
the representation.
LG.M.L’s surveyors took the terrestrial photographs with a
single camera, the optical axis of which was inclined with
respect to the horizon. It was mounted on a tripod and placed
in sequence at the end points of a line, almost parallel with
respect to the wall, 14 metres long and at a distance of 26
metres from the tower, taking advantage of the operational
conditions as best as possible.
The numerical compilation of this southern wall (oriented
toward the Amo river) was performed by means of an
analytical stereoplotter equipped with special graphic software.
The aerophotogrammetric flight was carried out by the
“Compagnia Generale Ripreseaeree” of Parma with a single
strip of four photographs, with 60% overlap, taken by a
wideangle camera and a flying altitude of 1500 metres a.s.1. .
The photogrammetric control points of the strip were made by
supplementing a topographic network already arranged for a
previous LG.M.I. cartographic survey.
The three-imensional compilation of the aerial photos was
performed by means of a mechanical projection stereoplotter
equipped with encoders and powerful graphic software applied
to a color workstation.
The equipment's capabilities allowed for the integration of the
terrestrial and aerial surveys in a unique three-dimensional
model, representing the characteristic surfaces of the built-up
area.
In this manner the most important structural elements of the
partially destroyed or damaged buildings were graphically
represented, together with the surrounding ones.
Several three-dimensional views were obtained. The simulated
models correspond to assonometric and prospectic
representations of fixed conditions of observation,
illumination ‚time and position of the surveyed area.
The images were successively submitted to an editing
operation in order to improve the videographic definition
without losing their characteristic digital appearance.
This was, in fact, made possible by means of retouching
software applied to a workstation of sixteen million colors.
Final elaboration was made on another station dedicated to
emulating the print of real colors; two types of corrections
were carried out on each image: one was to modify the color’s
intensity, while the other was to mask preferential areas in
order to obtain the desired chromatic effects.
The last phase of the project concerned the preparation of four-
colour process films through a high precision laser-plotter.
12
5. THE IMAGES
On the whole, forteen digital images were prepared whose
characteristics are described below:
Image 1 - General plan
Simulation lighting : solar light 0.7, ambient light 0.3
Time: May, 27 1993; hour 6 p.m.
Geographical position : latitude N41°, longitude E15°
Scale: 1/2000
Image 2 - General perspective
Exposure stations simulated conditions: camera focal length
50mm., elevation 500m.
Simulation lighting : solar light 0.7, ambient light 0.3
Time : May, 27 1993; hour 6 p.m.
Geographical position : lat. N41°, long. E15°
Image 3 - Perspective view of the area directly hit by the
explosion
Exposure station’s simulated conditions : camera focal length
50mm. elevation 150m.
Simulation lighting : solar light 0.7, ambient light 0.3
Time : May, 27 1993; hour 6 p.m.
Geographical position : lat. N41°, long. E15°
Image 4 - NorthWestern assonometric view of the Pulci tower
Simulation lighting : solar light 1.00, ambient light 0.3
Time : May, 27 1993; hour 6 p.m.
Geographical position : lat. N41°, long. E15°
Image 5 - Perspective view of the top stories of the tower and
surrounding buildings
Exposure stations simulated conditions : camera focal length
28mm., elevation 10m.
Simulation lighting : solar light 0.7, ambient light 0.3
Time : May, 27 1993; hour 10 a.m.
Geographical position : lat. N41°, long. E15°
Image 6 - NorthWestern assonometric view of the tower and
facing buildings
Simulation lighting : solar light 1.00, ambient light 0.3
Time : May, 27 1993; hour 10 a.m.
Geographical position : lat. N41°, long. E15°
Image 7 - Northern assonometric view of the tower and facing
buildings
Simulation lighting : solar light 1.00, ambient light 0.3
Time : May, 27 1993; hour 10 a.m.
Geographical position : lat. N41°, long. E15°
Image 8 - Southern assonometric view of the tower and
surrounding buildings
Simulation lighting : solar light 1.00, ambient light 0.3
Time : May, 27 1993; hour 10 a.m.
Geographical position : lat. N41°, long. E15°
Image 9 - SouthWestern assonometric view of the Pulci tower
Simulation lighting : solar light 1.00, ambient light 0.3
Time : May, 27 1993; hour 10 a.m.
Geographical position : lat.N41°, long. E15°
Image 10 - SouthWestern perspective view of explosion's
effects
Exposure station's simulated conditions : camera focal length
85mm., elevation 140m.
Simulation lighting : solar light 0.7, ambient light 0.3
Time : May, 27 1993; hour 12 a.m.
Geographical position : lat. N41*, long. E15?
Image 11 - Western assonometric view of the Pulci tower
Simulation lighting: solar light 1.00, ambient light 0.3
Time : May, 27 1993, hour 6 p.m.
Geographical position : lat. N41°, long. E15°
Image 12 - Western perspective view of the Pulci tower
Exposure station’s simulated conditions : camera focal length
35mm., elevation 70m.
Simulation lighting : solar light 0.7, ambient light 0.3
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B5. Vienna 1996