USA. e e Prepar 
Dept. of Civil Eng., Univ, of Illinois, Urbana 
  
U.S. Army Topographic Command, Washington E 
U.S. Coast & Geodetic Survey, Washington 
U.S. Geological Survey, Washington = 110 
ster 
Yugoslavia 
Geographical Institute, Belgrade Ds Sup. 
— Anal 
In addition, questionnaires were completed from project data published since perc 
1960 in scientific journals, symposia proceedings, reports etc., yielding form 
another sample of 189 questionnaires. = Pol 
The results of the analyses of these two principal samples are summarised freq 
below. Sri 
— As w 
nume 
6. Summary of main results anal 
6.1 General © © - Alth 
The following summary of a few statistics extracted from the completed question- can 
naires is only included here for ihe sake of completeness and to supply a few in p 
items of general interest. piam 
A. Ground Survey hal 
— The majority of projects (65%) did not use existing stations of a national he 
survey network to satisfy most of their ground control requirements. | Siri 
— A surprisingly large number of projects (24%) used signalised ground control 
points. Bloc 
B. Flight mission 
— Although film is the predominant photographic material used, a surprisingly 6.2. Me es 
large number of projects (18%) were photographed with a glass plate camera. This o 
— As regards the field angle of the camera, surprisingly little use is made the st: 
of the S.W.A. camera in practice, the percentages being N.A. 14%; W.A. 78%; errors 
S.W.A. &%. 
© © The di: 
— The photo scales were predominantlylarge scale; 10% larger than 1/5000; 
magnitı 
38% larger than 1/10.000 and 73% larger than 1/20.000 ostinm 
— Auxiliary data was not used in any of the projects supplied in the question- The oad 
naire response and infrequently in the projects collected in the literature 
search.