„2 = 
but also as accurate as possible, The solution to this problem 
is connected with the general arrangement of the radar profiles 
and the following cases may be noted;: 
In the first case, the profiles run parallel to the 
edges of the strip of photographs, within the limits of the common 
lateral overlap, as shown schematically in Fig. 3. After a suitable ! 
number of elevation points has been chosen for each pair of photo- 1 
graphs in accordance with one of the methods indicated, the contour 
map of any of the stereograms can immediately be made. 
  
| | À | | Flight axis 
uk JUN 
Airborne profile 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
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Fig. 3 i 
If aerial photographs are made simultaneously with the profile, 
then the horizontal scale of plotting can be established with the 
aid of the radar profile method. If difficulties are encountered 
in levelling individual models, the stereogram should be positioned 
so that the best correlation with models which have already been 
plotted is achieved and the deviations are distributed as evenly 
as possible over all the radar elevation points. This method has 
the advantage of being very fast since the mapping is based directly 
on the radar profile and all the intermediate steps are eliminated. 
Such a method will, of course, also be used in all those cases when 
the topography of narrow strips of territory is involved, as, for 
example, in the laying out of roads, power lines, pipe-lines, etc. 
It might be noted here that with this method the axial part of the 
strip is generally more accurately reproduced, because the effect of 
errors in the spot heights will diminish towards the axial portion 
of the strip. i 
Another method consists of laying the radar profile at 
right angles to the strip of photographs. The distance between 
them is determined by the length of the aerotriangulation strip | 
concerned. In this case, the radar profiles do not eliminate the 
necessity of aerotriangulation; on the contrary they form the basis 
of it.