Wild B9 Aviograph Small Scale Plotter 
Although the A9 can also be used for mapping, it would not be economic in a big office to use a trian- 
gulation instrument for the relatively simple purpose of mapping; it is more efficient to use cheaper 
auxiliary instruments in which the same reduced diapositives are used as have been used for aerotri- 
angulation in the A9. Their relative and absolute orientation is for this reason particularly easy to set 
up, because the transfer points have already been marked in the diapositives and their adjusted coor- 
dinates in the block are known. It is important that the plotting instrument should have, in addition to 
the strict geometrical solution and a high attainable accuracy, excellent quality in the observation 
system. Here again optical viewing is a decisive factor for the efficiency, as well as for the quality of 
the plotting. The B9 is also constructed on the mechanical plotting principle with space rods which 
intersect, and a tracing point which is freely moved by hand. This tracer carries the height scale pro- 
jection system and the drawing pencil (Fig. 15, 16). 
A pantograph with 14 fixed ratios provides for reduction of the model down to 5:1. The orientation 
elements are the swing, tip and tilt of both picture carriers, the adjustable model base, and the com- 
mon tip. 
The viewing optics enlarge the diapositives approximately 8 times, while a large angular field allows 
a wide view over the terrain being plotted. The ranges provide for a direct enlargement up to 1.6 times 
the original negative scale. One A9 can keep four to five B9 plotters fully supplied with pass points. 
Analytical Aerotriangulation 
The method of model triangulation in the A9 offers the particular advantage that possible errors in 
passing from one model to the next are discovered immediately during work on the Autograph. Fur- 
ther, a registration or reading error will show up only in its correct position and will not deform the 
whole strip. 
Nevertheless, many experts hold the opinion that the accidential errors of the plotting instrument can 
be reduced further, and that time can be saved when in the place of model triangulation, picture 
coordinates are measured in a stereocomparator. The scope ofthis paperdoesnotinclude examination 
of the advantages of these two methods; itis sufficient to state that the instruments for the analytical 
method are included in the Wild programme. The triangulation instrument is the STK1 Stereocompa- 
rator with EK4 Electric Coordinate Printer, and tape or card punch (Fig. 17). 
Diapositives at the same size as the original negatives are measured in the stereocomparator. The 
transfer pass points are marked in the diapositives using the PUG point transfer device; computation 
of model coordinates, block adjustment and transformation of coordinates are performed by elec- 
tronic computers. The same diapositives at the original size can be plotted in another new plotter, 
the Wild B8 Aviograph. 
The B8 Aviograph has been constructed with more in view than only the plotting of super wide angle 
photographs. Its possibilities are more versatile. For some time the practitioner has needed a small 
plotting instrument in which plotting work at small and medium scales can be carried out, and also for 
photogrammetric investigations for technical purposes such as geology, forestry and preliminary 
work in engineering surveys and land consolidation etc., as well for as the revision of topographic 
maps in a rational manner. The particular characteristics of this instrument are the strict geometrical 
solution, the spatial, mechanical plotting principle, orthogonal viewing with bright 6 x viewing optics, 
the possibility of exchange of the focal length for 15 cm or 9 cm with a picture size of 9" x 9" (that is, 
the possibility to use the instrument for wide angle and super wide angle photography) and the free 
hand movement of the tracer which carriers the drawing pencil and an illuminated exchangeable 
height scale (Fig. 18). 
The simple construction — with the same orientation elements as in the A8, the free hand move- 
ment of the A6, and briliant viewing optics — guarantees high performance, while the strict geo- 
metrical solution offers perfect model conjunctions. 
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