Flights flown between July 13, 1940 and July 17, 1940 by Woltz Studios, Inc., for the U. S. Dept. of Agriculture, Agricultural Adjustment Administration. Photos numbered Z-1A-3 through Z-3A-155. Scale not given. Stereoscopic coverage. Only indexes are georeferenced.
Logan County (Ill.) (W 89°36′--W 89°09′/N 40°19′--N 39°55′)
Illinois State Geological Survey
328 remote-sensing images, 2.22 gigabytes, average file 6.93 megabytes
Scanned from 9 x 9 contact prints (nominal scale ca. 1:20,000) on Crosfield Celsis 6200 drum scanning system at 750 dpi. Quality assurance target not published but available by contacting the Illinois State Library Map Dept. MrSID files compressed at a target ratio of 6:1. Uncompressed TIFF images on cd available from the Illinois State Library Map Dept.