For the first time, a standard U.S. Geological Survey map has been mass produced using fully automated computer technology. The l:24,000-scale topographic map of Park Ridge, 111., also depicts parts of Chicago, Des Plaines, Niles, Skokie, Wilmette, Winnetka, Glencoe, Northbrook, and Glenview.
The last major breakthrough in mapping occurred when aerial photography became an operational tool for cartographers after World War II. Now, computer systems can scan an original map to record contour lines and other permanent features. Next, a recent aerial photo is digitized, capturing details such as new roads, housing developments, and major changes in forests or wetlands. Finally, a cartographer at an electronic work station can add the new features to the terrain records stored in the computer to produce current map data.