-362 
[:3] T.J.. Blachut, "Mapping and Photointerpretation 
System Based on Stereo-Orthophotos', 
1971. Publication No. 12281. National 
Research Council of Canada, 
Ottawa, Ontario. 
[ 4] T.J. Blachut, "Das Stereoorthosystem, eine neue 
Losung auf dem Gebiete der Kartierung 
und Photointerpretation", Vermessung, 
Photogrammetrie, Kulturte.hnik, 
No. 1, 1972. 
[ 5] Published and unpublished information received from 
various manufacturers of orthophoto equipment.