é 
A TRANSFORMATION PRINTER FOR THE 
TERRESTRIAL PHOTOGRAMMETRY 
  
Abstract 
After a review of the facilities for plotting of terrestrial photographs 
in existing analog plotters, the author describes the new Wild UT 1 
Transformation Printer for Terrestrial Photographs. With its high optical 
and metric performance, this instrument provides the possibility of pre- 
cise photographic enlargement with a fixed ratio of 2 of terrestrial pic- 
tures with short focal length, on film or glass, in black-and-white or 
in colour. The transformed photographs are then compatible with the ranges 
of analog plotters. 
l. General considerations 
  
Two characteristics common to the cameras used for most terrestrial 
and short-range photogrammetry are their short focal length and their 
small image size. These criteria are imposed by the need for low 
weight and bulk for ease of transport. 
On the other hand, there are thousands of analog plotters in the world 
designed primarily for cartographic production from aerial photographs 
of considerably longer focal length and larger format. 
Between these two instrumentation systems, incompatibility frequently 
exists with regard to focal lenghts which can still be plotted direct- 
ly. 
There are, of course, analog plotters designed specifically for ter- 
restrial photogrammetry. It is not always certain, however, that 
their cost can be recovered taking into account the fact that ter- 
restrial photogrammetric work sometimes only occurs sporadically 
and, in addition, they frequently do not provide the necessary adapta- 
bility in view of the wide variety of photographs which can be taken 
in terrestrial photogrammetry. 
Faced with this situation, the user of the "analog chain" can only 
choose between the so-called "affine" method of plotting and image 
transformation by metric enlargement. 
The theory of affine plotting applied to aerial photogrammetry origi- 
nated several decades ago. Its consists in plotting the original pho- 
tographs with a principal distance increased by a suitable factor. The 
stereo-model is enlarged by this same factor only in the direction of 
the photograph axis (distances Y) while the scale in X and Z remains 
unchanged. The plotted figure is then restored to its exact proportions