Flights flown between June 21, 1940 and September 6, 1940 by Woltz Studios, Inc., for the U. S. Dept. of Agriculture, Agricultural Adjustment Administration. Photos numbered SK-1A-1 through SK-12A-25. Scale not given. Stereoscopic coverage. Only indexes are georeferenced.
St. Clair County (Ill.) (W 90°16′--W 89°42′/N 38°39′--N 38°13′)
Illinois State Geological Survey
507 remote-sensing images, 1.41 gigabytes, average file 2.9 megabytes
Scanned from 7 x 9 contact prints (nominal scale ca. 1:20,000) on Crosfield 646IE 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 12:1. Uncompressed TIFF images on cd available from the Illinois State Library Map Dept.