mean 
  
  
[um] Junits of Gy-6y P1,P3,P4 control variants e € 
9 G x mean 
303,0 9 9ymean 
—— approximating curves ® py | 
{30 | 
20 | 
"2,0 
107 P3 
r 1,0 ee 
P1 
Y T T yg 
5 10 15 20 strips 
Fig. 2: 0x mean, 0Y mean for 609% sidelap, wideangle photographie and errorfree control 
For each of the control variants an approximating curve is plotted in figure 1 and 2 representing 
the accuracy law of this variant. Due to the small differences between ox mean and oy mean always 
one curve is used for both coordinates. 
The accuracy laws found are pleasingly simple. In the case of a dense perimeter control (P1) the 
p 5 
mean square standard deviations ox mean — oy mean are a logarithmic function of ns. For the other 
3 control variants (P2, P3, P4) one gets a linear function of ns. 
The formulas 1 to 4 give the accuracy laws for 20 % sidelap and the formulas 5 to 7 are concerned 
8 y p 
with 60% sidelap. In the formulas with the letter a" the mean square standard deviations are 
expressed in um refered to the image scale. The letter b" indicates their presentation in units of the 
standard deviations ox = oy of the planimetric coordinates of the model points. 
Accuracy laws for the investigated planimetric control variants (Wideangle and error free control): 
P1: ox mean ~ oy mean ~ 5.2 pm + 2.1 um log ns 
(1a) 
ox mean/ox — oy mean/ay — 0.70 4- 0.29 log ns o. 
2 
  
P2: ox mean — oy mean ~ 6.1 um + 0.14 pm ng (2a) 
ox mean/ox ~ oy mean/oy ~ 0.83 + 0.02 ns (2b) 
P3: ex mean — cy mean — 6.1 um -- 0.37 um ns (3a) 
ox mean/ox — oy mean/oy ~ 0.83 + 0.05 ns (3b) 
P4: ox mean ~ oy mean ~ 3.4 ym + 1.8 um ns (4a) 
ox mean/ox ~ oy mean/oy ~ 0.47 + 0.25 ng (4b) 
60 95 sidelap 
Pl: ox mean ~ oy mean ~ 3.6 um + 1.5 um log ns (5a) . 
ox mean/ox ~ oy mean/oy ~ 0.50 + 0.21 log ns (5b) | 
P3: ex mean — oy mean ~ 4.3 ym + 0.23 um ns (6a) 
ox mean/ox — oy mean/oy — 0.58 + 0.03 ns (6b) 
P4: ox mean — oy mean — 2.5 um + 1.1 um ns Ta) 
ox mean/ox ~ oy mean/oy ~ 0.34 + 0.15 ns (7b) 
With control variant Pl the maximum standard deviations ex max and oy max of adjusted minor 
control point coordinates appear at the perimeter in very small blocks and in the blockcenter when 
the blocks are larger. With the control variants P2, P3 and P4 ex max and ey max appear always at 
the perimeter of the block. 
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