Flights flown between June 27, 1938 and August 12, 1938 by Iowa Aerial Surveys, Inc., for the U. S. Dept. of Agriculture, Agricultural Adjustment Administration. Photos numbered BHB-1-2 through BHB-6-27. Scale not given. Stereoscopic coverage. Only indexes are georeferenced.
Richland County (Ill.) (W 88°18′--W 87°54′/N 38°51′--N 38°34′)
Illinois State Geological Survey
257 remote-sensing images, 1.36 gigabytes, average file 5.43 megabytes
Scanned from 7 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.