2. The Autograph required the least amount of measuring time followed by the analytical plotter, again 
a close second, and the stereocomparator. 
3. Five or six models proved to be the optimum bridging distance for polynomial adjustment. 
4. A 2nd degree polynomial for the planimetric adjustment and a 3rd degree for the heights appeared to 
be the most suitable combination. 
3 When a decision is made about the instrument to be selected consideration should be given to the other 
tasks a certain instrument can perform apart from aerial triangulation. 
12. Ebner, H. 
Germany (F.R.G.) 
THEORETICAL ACCURACY-MODELS FOR BLOCK TRIANGULATION 
The analytical-block triangulation (bundle method) and the block triangulation with independent models, are 
the most general and most efficient methods of aerotriangulation applied today. 
To exhaust the full accuracy potential of those methods, in practice, detailed investigations on their theoretical 
accuracy properties are necessary and appropriate. 
For the planimetric coordinates of adjusted blocks with independent models. Ackermann found very 
favourable accuracy properties, particularly for dense perimeter control. Similar studies for bundleblocks made 
by Kunji, Talts, Gyer, Kenefick and Kilpeld have confirmed the favourable planimetric accuracy and have 
shown that without the use of auxiliary data high vertical accuracy can only be achieved establishing a 
two-dimensional and relatively dense net of height control. 
Those investigations were supplemented and extended to large blocks with up to 10,000 models at the Institut 
of Photogrammetry at Stuttgart University. The results may be summarized as follows: 
- The planimetric and the height accuracy is significantly better in bundleblocks than in blocks of 
independent models. 
- In the case of dense perimeter control the standard deviations of adjusted planimetric coordinates 
increase only with the logarithm of the number of models. 
- The height accuracy is only a function of the area density of height control, independent of the block 
size. 
: Sidelap of 60% improves the accuracy in all three coordinates approximately by a factor v 2 and allows, 
in addition, lesser density of height control. 
13.  Fondelli, M. 
Italy 
TESTS AND OBSERVATIONS ABOUT THE ANALOGICAL 
AND ANALYTICAL TRIANGULATION METHODS 
THROUGH THE GALILEO-SANTONI EQUIPMENT 
The author develops a short critical examination of the results obtained during these last ten years in carrying 
out the spatial aerial triangulation, and points out the problems to be solved to further improve the results. 
Going on with his critical examination, he mentions the actual sensitivity threshold concerning the actual 
operational mode. 
He describes some stability and analytical triangulation tests carried out at the Galileo-Santoni stereocompara- 
tor. At last, he analyses the operational mode advised to carry out the aerial triangulation through this 
equipment compared with that one already tested and checked for analogical proceeding by independent 
model through the Galileo-Santoni stereosimplex mod. III and mod. Ilc. 
The final conclusions allow to obtain some technical and economical information to carry out the spatial aerial 
triangulation at the analytical plotter in question. 
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