Following this, the computation of mean square values of the residuals has been 
repeated for the remaining ground control points. These values are listed in Table YI6. 
Tables AAa and VIb show that with second-degree adjustments, the best result 
has been obtained with the Zeiss Jena measurements, while the Wild A7 results are 
the poorest. The same conclusion had been drawn already from the mean square 
values of the relative errors in the tie points, listed in Table IV. 
However, in the case of corner control only, the Wild A7 results are the best. 
As shown by the graphs with the residuals in the ground control points, this is caused 
by the larger systematic errors in uncontrolled areas for the Zeiss Jena and the Nistri 
TA3 adjustments. 
Table VIb indicates that for the specified purpose of the test, which is mapping 
at the scale 1:100000, each of the ten adjustments gives a satisfactory accuracy. 
The adjustments on perimeter control give an acceptable accuracy for plotting at the 
scale 1:50 000, and the adjustments on control along the western and eastern sides 
are only slightly less accurate than those on perimeter control. 
The two third-degree adjustments with corner control are somewhat less accurate 
than the corresponding second-degree adjustments. Apparently, the greater flexibility 
of the third-degree adjustment entails a greater possibility of introducing unwarranted 
deformations and, thereby, systematic errors. 
e) Best possible accuracy of the block adjustments 
In addition to the above results, it is of interest to know what the best accuracy 
is that could possibly be achieved by means of the method of second-degree conformal 
transformation of strips. This accuracy can be computed in two ways: 1) by using 
all available ground control points for the computation of transformation formulas 
for individual strips, and 2) by not increasing the number of ground control points 
in the block adjustment but ensuring that no perceptible identification errors occur 
in the used points. 
Accordingly, each strip has been transformed using all ground control points 
that have no obvious error larger than 10 m. In addition, the block adjustments with 
perimeter control have been repeated after replacing a number of control points that 
have errors not representative of those in surrounding points. The following points 
have been replaced: 
Zeiss Jena 
Nistri 
41 by 
42 
5 
by 4 
3 (missing) 
by 4 
192 
191 
19 
20 
271 
by 
270 
118 
193 
41 
37 
271 
273 
192 
119 
271 
265 
297 
298 
In each case the mean square values of the residuals have been computed. These 
are listed in Table VII. 
36