15 
The block adjustment gives the following results: 
absolute precision 
mn = 4.1 m = 0.49°/oo Z 
m x = 4.1 m = 63 [xm 
m y = 4.2 m = 63 gm 
relative precision 
m h = 0.94 m = 0.12°/ oo Z 
m x = 1.25 m = 19 gm 
m y = 1.24 m = 19 gm 
Unfortunately the precision of the block adjustment as such cannot be evaluated from the 
absolute precision because of poor identification of the 245 check points. Looking at the 
relative precision which is an indication of the internal precision of the adjustment, we 
see that the precisions in height as well as of the planimetrie coordinates of the pricked 
points, are excellent. 
2. OEEPE Comm. B block 2.6 of the Reichenbach test area 
Prof. Cunietti presents a report of the activities of Comm. B to the Lisbon congress. We 
mention here only the result of this block of 5 strips with 46 models. The location of height 
control points was the same as in the previous block. Only planimetric ground control 
points located along the four edges of the block were used with the Jerie block adjustment 
method. The results of these observations in the Wild Stereocomparator were considerably 
better than those of the previous block, viz. residual j-parallaxes of 4.5 microns in the 
orientation points and 7 microns in all other points. It may be that the use of ultra flat 
glass plates in the RC7 camera caused this better precision. The block has been treated 
twice, because two separate triangulations were carried cut. 
The results of these two adjustments are the following: 
absolute precision 
1st cycle mn = 24 cm = 0.20°/ 00 Z 
m x = 19 cm =16 gm 
m y = 16 cm =13 gm 
2nd cycle mn = 27 cm = 0.23°/ 00 Z 
m x = 21 cm =18 gm 
m y = 17 cm = 14 gm 
relative precision 
mn = 11 cm = 0.10°/oo Z 
m x = 8 cm = 7 gm 
m y = 10 cm = 8 gm 
mn = 12 cm = 0.10%o Z 
m x = 10 cm = 8 gm 
m y = 12 cm =10 gm 
It may be mentioned that on one of the two triangulations the ITC-anbloc method for 
planimetry has been applied also, using the same control points. The result was the same 
as with the Jerie Analogue computer. 
3. Triangulation South Wales (see for this [48]) 
This triangulation was carried out in order to determine with what precision photogram- 
metric mapping is possible without any ground control and based on the use of APR data 
only. The use of 25 height control points and 8 planimetric control points was intended 
to compare the results obtained with and without ground control. Unfortunately these 
results proved again that the ultimate precision, which can be obtained, depends more on 
the quality of the photographic material than on the method of observation or adjustment 
of the observations. The standard deviations are as follows: 
using ground control using only APR 
Height adjustment mn = 1.8 m = 0.32%o Z mn varies from 2.3 m to 2.6 m 
Planimetric adjustment m v = 4.5 m = 122 gm m v varies from 5.3 m to 5.5 m 
These figures are obtained from the second cycle of observations carried out in 1962 in 
diapositives made by Fairey Air Survey Ltd. These results, as far as they can prove any