Aerotriangulation 
  
During this period the photogrammetric control point extension methods 
have been so well established that only model triangulation with stereo- 
instruments and bundle adjustment are applied at present. During the 
term the bundle adjustment method has been used in routine production, 
and special attention has been paid to the technical details of the 
process. 
At ‘the Institute of Photogrammetry a minicomputer HP 2100, which controls 
the comparator measurements, has been connected to a Zeiss PSK comparator 
for bundle adjustment aerotriangulation, and the set of programs operates | 
inter-actively. 
Also the National Board of Survey has à Zeiss PSK stereocomparator for 
bundle adjustment aerotriangulation. At the Tampere University of 
Technology co-ordinates are measured with two monocomparators of the 
types DBA-Comparator and Ascorecord. The National Board of Survey performs 
its adjustments with its own NOVA computer. 
Two- or three-dimensional model triangulation is used both by the National 
Board of Survey and by private engineering companies. Depending on the 
requirements of accuracy, various instruments are used, including Wild A8, 
Wild A7, Zeiss Jena Topocart B, Steroplanigraph: C5 and Wild B 85. At the 
end of the term the company Finnmap procured a computer of the type HP 2 000 
for calculations of model triangulation. 
The annual output of the National Board of Survey is about 500 models 
with the model method and 600 pictures with the bundle adjustment 
method. Finnmap triangulates about 900 models with the model method. 
The Technical Research Centre of Finland triangulates annually about 800 
photographs with the bundle adjustment method and the Tampere University 
of Technology about 100.