Coordinate System:Images were created using the State Plane 1983, Ohio North, units in Survey Feet coordinate system.Substituted Images:If tiles were missing from the original countywide image coverage, other available imagery within 2 years of that year were substituted whenever possible.Image Artifacts:As part of the mosaic process, a color had to be selected to be set as the transparent color for each tile. The color selected was White (pixel value 254). If a tile contained pixels of this color, those pixels would become transparent and would display any non-white pixels from adjacent tiles that overlapped the same area. If this happened, you may notice image artifacts throughout the .sid file. This is part of the GeoExpress program and there was not any way to correct this issue according to Lizardtech support.Metadata:Imagery flown at 1:20,000 scaleDates Flown:June 12, 1965August 29, 1965September 3, 1965September 10, 1965September 30, 1965October 14, 1965