The time required for the measurement operations is much less than that 
normally needed by plotters because the formation of the optical model is eliminated; 
in fact, the photographs are placed in their frames as if coplanar and are maintained 
in such position for the duration of the measurement operations. 
The problem, therefore, is solved in the simplest and best way, and when the 
conditions of the exposure and adjustment of the camera for the interior orientation 
of the photograph are improved, the procedure will supply the greatest guarantee 
of accuracy, in the determination of the data for the exterior orientation of the 
photograph. 
Let us now take a glance at the plotters. Having taken away from the plotters 
the task of performing aerial triangulation, what economies can be attained in their 
materialization ? 
First of all, it is obvious that many parts, now necessary for that service, will 
become superfluous and thus can be abolished. Besides, also the precision now 
required. for that operation can be reduced, to the benefit of greater stability and 
cost of the plotter. 
Universal plotters can be employed, for some special uses, but because the 
normal application is that of planimetric photographs, the greater part of the 
plotters can be limited to the performance of that particular task only. 
A tendency in this direction has been present for a long time with the develop 
ment of simplified plotters, intended only for the use of almost nadiral photographs, 
the performance of which simplified plotters has been degraded for reasons of 
economy. But the arrival of new digital procedures opens the way to further 
simplifications. 
The analytical method with stereocomparators and electronic computers 
furnishes the following data: 
A. The position (spatial coordinates) of the reference points chosen on the 
photographs for their bridging; 
> 
— 
- 
.. Elements for the position of the photograph in space that is, t», and 
= 
K angles; 
C. by, by, b, base components for each pair of photographs of the series. 
Which and how can these data be used in plotters for the formation of the 
optical model? 
Naturally, there are the reference points for each photograph, the position of 
which is obtained according to the new procedure. In this case, all present plotters 
can be used by following standard practices. 
But important simplifications can be achieved in the materialization of photo 
grammetrical plotters by following the concepts I will expound and which tend 
not to utilize the control points, but the elements for the exterior orientation of 
the photograph as provided by computation. 
Setting of the exterior orientation of the photograph, by using the graduations 
of the camera supports, is to be excluded because that would require a precision 
and an adjustment condition of the instrument which would make the cost much 
higher than that of today and its use even more uncertain, inasmuch as the 
correction of the eventual inevitable residual errors in the reconstruction of the