PS 
me 
  
. Verbal data 
. Position error of tie points 
. Grid lines 
If there were some errors or some 
among these subjects or anything beyond the 
technical specification limits, they were pointed 
out on the sheets and sent back to the contractor. 
missing items 
After they were corrected and completed by the 
contractor these sheets were also certified. 
3.3. Geodetic Control 
Geodetic control was performed on the 10 % of the 
sheets choosen by sampling method. We have used 
total station (electronic tacheometer), Zeiss 
Elta-3 and REC-500 recorder, on the field. Later, 
Intergraph 32-C workstation was also used. By 
using IGDS graphical software package, field data 
had been compared with the design file. 
In order to check the application quality of these 
maps, optical plump ZLN is utilised. It was a very 
handy tool, to point out the projection point of 
the roof corners on the ground. 
3.4. Analysis and Evaluation 
of the control 
in this five phases are 
The analysis and the evaluation 
measurements carried out 
as fallows: 
. Planimetry 
. Neighbourhood 
. Point height 
. Contour height 
. Application and updating 
3.4.1. Planimetric error of arbitrary point which 
can be well defined was computed by this 
formula, /4/. 
   
Ex = Xphotogrammetric ” Xgeodetic 
Ey 7 Yphotogrammetric " Ygeodetic 
ZEx f£. 
a, = AZ gy = 
n. Ny 
In the first check after having measured 652 
had been 
which were 
points, position error m = + 13.8 cm. 
found. On the other hand, differences 
explained above are shown, in table 1: 
195 
  
  
Differnces Measured point Percentage 
Number 
0 - 10 cm 234 36, 76 
31 .~ 20 259 40 
21 - 31 Hy 18 24 
3l - 40 42 6 
652 100 
  
  
  
  
  
Table 1: Differences for position 
As it is shown in table 1, 76% of the 
measurements were suitable to technical 
specifications. However the rest 24% of the 
measurements needed to be corrected. These sheets 
were sent to the contractor back. In the second 
(or third) check, they were also found to be 
suitable. Therefore we confirmed them. 
3.4.2. The differences for neighbourhood were also 
computed, by the formula: 
  
é = Distance -Distance 
(map) (control) 
Where é is the difference between distance in 
map (digital photogrammetric data) and the 
distance measured by the control team on the 
ground. And from the first check neighbourhood 
error m, = + 10.9 cm has been found. 
  
  
Differences Measued distance Percentage 
Number 
0-10 em 314 2 85 
11 - 20 154 28 
21 — 31 61 124 15 
31 - 40 19 3 
548 100 
  
  
  
  
  
Table 2: Differences for neighbourhood. 
By the way, as it is shown in table 2, 85% of the 
differences on measured distances were suitable to 
technical specification. Other 15% of the 
differences needed to be corrected. These sheets 
were sent to the contractor back. And later on, 
second (or third) check was done. Then it has been 
seen that they were all corrected. 
3.4.3. For the point height control, according to 
the test results, avarage height error of well 
identified points had been found as my = t 11 cm. 
3.4.4. For the control of height error of contour 
lines 5 crossections were measured and compared 
with the design file. In each crossection there 
were 15 points. As a result the mean height error 
of contour lines was found to be + 20 cm. So, at 
the end of Geodetic control, all measurements were 
found to be acceptable and they were confirmed.