SESSION 5: 
  
ON-LINE PHOTOGRAMMETRIC TRIANGULATION - 
QUALITY CONTROL 
  
  
CHAIRMAN: A.A. Elassal (USA) 
AUTHOR: K. Jacobsen (FRG) 
TITLE: OPERATIONAL ASPECTS OF DATA ACQUISITION 
DISCUSSION: 
Elassal: Thank you, Dr. Jacobsen, any questions? 
Crün (Switzerland): You said that the technique of transferring 
Jacobsen: 
Grün: 
  
Jacobsen: 
Grün: 
tie points across strip direction does not stand 
the test, because the operator is dissatisfied and 
can't handle the procedure. I do not quite under- 
stand why not, if the procedure is appropriately 
supported by software. If this is done, I cannot 
understand why the operator has problems. 
Yes, the operator has not had problems but the oper- 
ator has much more to do with handling the photos 
and with the measurement itself. That means the 
photos have to be inserted again only for the 
measurement in a standard case of three points and 
in maximum five points and if we have an irregular 
photo flight like usual then it can happen that he 
can measure only two points in the sidelap area of 
the strips. 
Are you talking about 20 $ sidelap only? 
In the case of 20 $ sidelap. If you have much more 
sidelap like 60 $ then it is in general better to 
use the procedure which I have described. That means 
to measure at first double blocks and to have an 
automatical pointing based on preliminary computed 
ground points. 
An additional question. There is, of course, the 
aspect of building up very quickly a reliable net- 
work and as you know, as long as you work in one 
strip alone it is not reliable enough, so you would 
like to go with your measurements as soon as poss- 
ible across the strip in order to build up a reason- 
ably reliable network, in order to detect blunders 
as early as possible. Is that a valuable aspect? 
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