SANTONI SOLAR AEROTRIANGULATION - WORKING METHODS 
ADJUSTMENTS AND RESULTS OF LATEST EXPERIENCES 
by CARLO TROMBETTI 
Military Geographic Institute, Florence 
SUMMARY. — The latest studies and experimental works performed by I. G. M. and E. IL. R. A. in the 
field of aerotriangulation with Santoni's methods, have 
been intended to find out the working procedure most 
suitable for its practical application (Premise). 
It is established that Santoni’s method of aerotriangulation differs from other methods because the 
imposition of the transversal and longitudinal tilt of each new photograph does not depend on the elimination 
of the vertical parallaxes among some points of the optical model, but on the knowledge of the altazimutal 
position of the sun and of the angular position of the camera axis with respect to sun direction at the mo- 
ment of exposure. The analytical procedure and the special instruments are described, by which the above 
mentioned inclinations can be determined from the data collected trough the solar photograph ( 
A critical examination of the special apparatuses (solar periscope, 
chanical calculator) and the usual instruments ( 
chap. 1.). 
solar photogoniometer, solar me- 
Santoni camera mod. IV, Stereocartograph mod. IV) which are 
needed for an aerotriangulation according to the Santoni's solar method, leads to the exposition o 
f the draw- 
backs and advantages shown by the experience (chap. 2.) 
Entering into the actual carrying out of the experiment, the conditions of the exposures and ground 
surveys are described. It is shown that as a result of ground survey the strip— 
about roo km in length—disposes 
of three terrestrial controls : 
at the beginning, at the middle and at the end (chap. 3.) 
From the field surveys, one passes to the preliminary calculations 
of photographs. 
and tests proceding the connection 
Carefully described is then the research concerning the setting of the camera 
with respect to the plotting instrument. This research is carried out on the pai 
control, and leads to the determination of a constant — if there is any — to be ass 
for all pairs (chap. 4.). 
-periscope, on its whole, 
rs provided with ground 
umed as corrective factor 
One enters the working details of the photographic bridging. The analysis of the nadiral photographs 
connection comes to the noteworthy conclusion that it can provide the swing values of the intermediate 
photographs for the subsequent calculations : 
but it can not always provide a reliable value of the systematic 
error in the tr 
ansfer of swing. The tecnique of the solar, definitive connection is then exposed, 
with the rough 
results at the and of the strip (chap. 5.) 
Passing to the selected method of adjustment, its informative criteria are outlined which can be sum- 
med up as follows : 
19) — The systematic error, whatever it may be, is calculated according to its effects inside the last model. 
2°) — According to the entity and sign of the deformation which is examined in that model, the systematic 
corrective factor is calculated, and then the strip adjusted. 
3?) — The residual closing errors, referred to the geodetic net, are ascribed to accidental errors, and adjusted 
linearly. 
The acquired results show, in the present case, a heavy influence of accidental errors mostly due to 
the photographic definition. The solar method supplies, in cases like that, the possibility of reducing several 
bridges of the same aerea to a sole angular bridge, se that the influence of the residual accidental errors can 
be put in evidence independently from the angular setting of the cameras. It follows th 
at their influence may 
be reduced by taking the mean of the various connections. 
The final results prove that the solar methods 
allows also removing «a posteriori » many troublers of photographic views (chap. 6.)