15 
SOLAINI, L. TROMBETTI, C. 
President of the scientific President of 
Commission of the aerial Commission A. 
triangulations 
Report on the preliminary work of Commission À. 
(Aerial triangulation on small and medium scales) 
of the 
European Organization for Experimental Photogrammetric 
Research (O.E.E.P.E.) 
PART 1. PROGRAMME AND ORGANIZATION OF THE WORK. 
1. Many difficulties due to the organization and the starting of experiments on an 
international footing have prevented us from completing the very heavy pro- 
gramme of Commission A of the OEEPE before the Stockholm Congress. 
The very large amount of photographic material, the necessity of reproducing 
several copies of the original negatives and of pricking the triangulation and scale 
transfer points, the measurements carried out in the terrain to determine the many 
control points, required much more time than originally estimated. As a result the 
work of restitution has only just begun. 
We regret that we are not in a position to show the members of the International 
Congress for Photogrammetry the results of the aerial triangulation and that we 
are obliged to limit our communications to the description of the detailed pro- 
gramme of the preliminary work and operations. 
Nevertheless, in our opinion, the account of the principles adopted for the very 
important work of our Commision — work which represents the first example of 
a large international cooperation in the domain of photogrammetry — will be 
very useful and may lead to interesting discussions during the Congress. We 
wish to point out that every decision reached has first been the subject of 
thorough discussion during long sessions of the Commission. 
We wish to express our most sincere thanks to all those fellow-members of the 
Commision who, by their kind cooperation and their freely informing us about 
their views and experience, have contributed to our preparatory work. 
This report is divided into two parts: the first deals with the general programme, 
the methods of determining the control points, the test of the cameras and the 
instructions sent to the institutes charged with the execution of the aerial trian- 
gulation; the second part deals with the work in connection with the determination 
of control points, the aerial photographs and the preparation of the strips. 
N 
Initial programme. 
The statutes of the Organization have served as a basis when setting up the initial 
programme. These statutes provide "an objective and sufficient comparison of the 
latest methods for aerial triangulation." 
In order to have a statistical value, these tests require many comparable obser- 
vations, executed under conditions similar to those in industrial practice. 
Moreover, the experiments have been carried out in such a way as to permit other 
investigations of errors and their propagation, such as the study of the use of 
film and plates for aerial photography, the compensation of blocks, etc.