41 
a simplification 
iy a sufficient 
5 the research 
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implemented. 
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structural, wall 
¡orations etc..., 
ted ones, of 
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ts of the lines 
the transverse 
been set in the 
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lination. 
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dence of the 
ol that in this 
neasurements 
> the accuracy 
nic theodolite 
res enabling it 
anithal angles 
with accuracy of ± 1 cc , overlapped by diastimeter DISTO, 
that is able to measure the distances with accuracy of ± 3 
mm + 1 p.p.m.. The capacity of the instruments configured 
in that way reaches 100 m considering characteristics of 
the reflecting surface. As it is already well-known, a 
diastimeter without reflectors performs the measuring over 
the area determined by the intersection between emission 
cone of the signal and the reflecting surface. That area, 
then, increases in proportion to the distance and varies 
from 6 mm to 60 mm for the distances between 10 and 
100 m. 
The correct collimation of the points is being marked by a 
small laser tracer of Class 2 fixed on the side of DISTO. 
A limited distance (approx. 15 m) between the vertices of 
the measuring stations and the elements to be measured 
has imposed a need to work with a very small zenithal 
angle. 
For the presumed values, moreover, the propagation of 
the variance within measure of the azimuthal angles, has 
failed to produce negative practical effects notwithstanding 
very inclined visibility distances and the negative effect of 
the residual error of vertical position. 
The measurement of the profile, as it has already been 
said, repeated independently from two nearby measuring 
stations (half of a profile from each station) has enabled to 
verify a result and exclude the arising of the systems. 
With well-known expressions: 
AO = k sen z+ D cos z 
AX = - k cos z sen a + D sen z sen a 
A V = -k cos z cos a + D sen z cos a 
where a and z are the values of the measured azimuthal 
and zenithal angle, D is an oblique distance measured 
from diastimeter and k is a distance between collimation 
axis of a theodolite and an axis of a diastimeter, the value 
of the coordinates of the measuring points have been 
determined reduced to a unique reference system. 
In total, 1800 points (fig. 4) have been measured that, 
thanks to a simple calculation program, have been 
transformed into a DXF file, structured at different levels. In 
that way, it was possible to visualize the results of the field 
work through the graphic symbols of different colours, each 
corresponding to the respective measuring station where 
from the points have been acquired; that have made 
immediately obvious the correspondence of the profiles. 
Figure 5 
Transverse section obteined with 
topographic data. 
Figure 6 
The same section integrated with data 
achieve from digital image rectification. 
Figure 7 
An example of image rectification aimed 
to survey plain surfaces.