is the precence of superabundant amount of points distributed along the strip: in prac- 
tical operations are most rare the cases of adjusted strips with known points at the 
ends only. 
Both the larger diffusion of electronic computers and the use of recording plotters 
have consequently allowed a remarkable use of mechanization in the adjustment 
computation. 
In practice, the auxiliary instrument data are never used for carrying out adjust- 
ments. 
Precision obtained. — 'The data gathered through the questionnaire certainly do 
not allow to attain some scientifically reliable results on a subject as complex, important 
and delicate such as the one of aerial triangulation precision. Rather than stating nu- 
merically the precision attained, most of replies are stating that the required precision 
has always been attained. 
To obtain this precision, the several Organizations have been compelled to work 
on the only parameter available, increasing in a proper way, the amount of control 
points of strips. 
Because of this essential difference of proceeding it is not possible to analize 
comparatively the data supplied and listed in tables. 
4. — GENERAL CONSIDERATIONS ON THE PROCEEDING OF AERIAL TRIANGULATION PER 
BLOCKS WITH THE INSTRUMENTAL METHOD 
a) Since the very beginning, it is necessary to make clear a question which 
arises as soon as proceedings of triangulation per blocks are considered separately 
from the ones per strips. 
Often, 1t 1s thought that the distinctive characteristic between the two proceedings 
1s to be sought only in the way of carrying out either the strip adjustment as an auto- 
nomous entity, or the adjustment of strips concerning the only body which is the block. 
In such a case, then, there would be no reason to keep clearly separated both 
proceedings, as it is sufficient to distinguish the two adjustment proceedings only. 
To our opinion, however, the two proceedings are not only different in the last 
part, but they present in all the following working stages clearly different character- 
istics which can be noticed only through a total observation of proceedings. 
In the proceeding per blocks everything since the very beginning, has to be esta- 
blished to the aim. 
The flight for carrying out a block of strips has more restrictive and precise re- 
quirements than those of a flight for carrying out independent strips. Besides, the 
bridging and preparation of single strips requires an homogeneous way to proceed 
and a preestablished study of the side connections not foreseen for simple strip. 
In fact, looking through table N° 5 concerning triangulations per blocks with the 
instrumental method, we notice, right for the complexity of the problems involved, 
that this proceeding requires a strict uniformity of course. In fact, variants are lower 
and structural differences are less substantial. 
The scheme form of the scientifical research is here unaltered right because, other- 
wise, in the large amount of data it would be difficult a non studied and strict procee- 
ding. 
Owing to this structural difference, therefore, both proceedings, in our Report, 
will be kept separated and separately analized. 
18 
  
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