For each quarry it has been surveyed a local network: 
1.1.2 The georeferentiation of the detail vertexes 
The georeferentiation of the detail vertices is obtained respect 
to the vertexes of the fixed GPS network described upper. On 
these secondary vertices it is possible to make station with the 
topographic instruments for the detail measurements. The 
vertexes of the detail network, propagated from the primary 
vertexes, can be materialized through quick modalities. These 
vertices can be easily repositioned and the position can be 
calculated ex novo from the primary vertexes; the primary 
vertexes have to be positioned where is non prevented the 
activity of extraction, perhaps around the limits of the quarry. 
The connection of the local GPS network with the Gauss- 
Boaga system has been obtained connecting one or more points 
to one IGM95 vertices and to two altimetric points belonging 
to the fundamental network. 
All these measurements of the three local network has been 
processed together by least square adjustment. 
1.2 The Survey of the detail 
The second phase of surveying is the survey of the details. In 
function of the typologies of the quarries the instrumentation to 
support the survey detail has been chosen: two are the 
methodologies that can be adopted in function of the different 
typologies of the quarries. 
For the under water quarries (quarry at the ground water table 
and at the stratum superficial) it has been used a GPS (RTK 
modality) associated to an echo-sounder, for the open quarries 
it has been used a total station motorized no prism. 
We have to remember that this survey is finalized to the 
estimation of the volume of the area of extraction and to the 
building of a DTM which have to satisfy the characteristics of 
the precision for this work. 
The survey of the detail has to be integrated with further 
information about the characteristic elements of a quarry, such 
as the position of the electric network, buildings, and other 
which allow to better represent the quarry. 
Two are the methodologies that can be adopted in function of 
the different typologies of the quarries. 
1.2.1 Open quarry 
The instrumental characteristics. To survey sectors of the open 
quarries is suggested to adopt a total station motorized no 
prism positioned on the vertexes used for the georeferentiation 
or for the vertexes of integration. This kind of advanced 
instrumentation has impulse laser range finder that allows to 
measure the distance, without prism, of many hundred of 
meters using the natural surfaces like reflective surfaces. With 
these instruments is possible to improve the accuracy of the 
volume estimation thanks to the points density that can be 
obtained with the automatic modality and determining 
homogeneous areas inside which the terrain is scanned. These 
total station motorized can survey some thousands of points per 
hour. The data surveyed (azimuth, zenith directions and 
distance). Data are registered on file ASCII. 
Generally the open quarries are characterised by fronts with 
steep slope. 
The applications have shown the obvious necessity to acquire, 
during the survey, the breakline located in the quarry area. 
Consequently is extremely important to realize an higher 
density grid of points. Only in this case it can be obtained the 
precision necessary to avoid conflicting on the volume 
estimation. Also the density of the points has a fundamental 
role particularly in the case of irregularly surfaces like it’s the 
case of the quarry. 
In the following table is shown that assuming as a datum 
volume ( the definitive configuration) the one obtained using 
all the points surveyed (14929), the percent of error drastically 
decrease from a 50x50mt grid to a 5x5m or 2x2m grid. 
Fig. 6 The survey of an open quarry with higher concentration of points in correspondence to the change of slope and of steep slope 
(Verano Brianza).