The Wild A9 Wide Angle Autograph 
Following the decision on the half format, a triangulation instrument was built, the Wild A9 
Wide Angle Autograph. Like the well-known Wild A7 Autograph, it is based on the mecha- 
nical principle. Observation of the model is made through a 10 x optical system with orthogonal 
viewing over the whole picture range (Fig. 11). 
For facilitating progressive aerotriangulation by the method of conjunction of successive models, the 
exchange ofleft and right picture in the eyepices, and optical picture rotation by means of dove prisms, 
is provided. The bases can be set in the inner or outer position. 
At first it was considered that a graphic aerotriangulation would be sufficient i. e. the position of the 
transfer pass points would be plotted on the A9 plotting table, and only the heights would be read. 
However, experience with the EK3 Electric Coordinate Printer for A7 and A8 Autographs had led to a 
more rational form of aerotriangulation, with registration of all coordinates of the pass points in typ- 
script and in punch cards or punch tape (Fig. 12). The block adjustment is made either by computing 
or analogue methods, e. g. the ITC-Jerie method. 
The Point Transfer Device 
In order to carry out block triangulation in the A9, the transfer pass points in the individual flight 
strips and in the overlap common to adjoining strips must be marked in such a way as to provide 
perfect model fitting with complete certainty. For this purpose a special instrument, the Point Transfer 
Device (Fig. 13, 14), is used. The device has been constructed for this particular purpose: identical 
picture points are slected and marked by drilling a tiny hole in the emulsion, this process being carried 
out under stereoscopic viewing. 
  
  
Fig. 13 
The transfer pass points are pricked in the 
diapositives using the Wild PUG1 or PUG2 Point 
Transfer Device, guaranteeing faultless identification 
of the points in the adjoining strips of a block 
triangulation. 
Fig. 14 
For easy finding of the points pricked in the PUG, a 
circular mark is automatically drawn around the point 
by a crayon during the transfer pricking process. 
11