DIGITAL TECHNIQUES FOR MAP COMPILATION 
229 
shades (although the signal-to-noise 
ratio with present light .intensity is 
sufficient for useful operation only in 8 
levels). 
3. In the Record Mode, the system con 
verts digital information to modulate a 
light beam to expose a photographic 
film. The same resolution and gray- 
shade range described above are avail 
able in the Record Mode. 
The DAMC Scanner-Printer is an electro 
optic-mechanical device, consisting of the 
following major elements: 
1. WILD STK-1 stereocomparator—This 
unit functions as both a measuring ma 
chine and a scanning bed. The stereo 
Fig. 6B. Contour map produced by the Sequential System I,