the editing capability of a 2250 III attached to a 360-50. A 
navigation overlay from a U.S. Coast and Geodetic Survey chart 
section was manually digitized, displayed on a 2250 III, (Figure 
2) changed with light pen and keyboard action, and plotted on a 
Geospace plotter. This work was under the direction of Dr. 
Horace Flatt assisted by Robert Jefferson. 
In Figure 5, the concept of a composite system is shown. 
When additional application programming is instituted, such a 
composite system can be developed for conversion of map manuscripts 
to operation negatives. 
The published accuracies of automatic contour and orthophoto 
map production are currently approaching that of manual methods, À-+1 
In most published results, the final output requires considerable 
redrafting and editing for engraving and producing map-separation 
negatives of cartographic quality. Consequently, a large portion 
of productive mapping for publication is expected to prepare com- 
pilation sheets manually for some time, particularly at scales 
larger than 1/24,000. 
The Problem of Estimating System Data Parameters 
The wide variances in map format, size, scale, precision, 
accuracy, and image quality require numerous definitions in order 
to adequately classify, discuss, and specify the use of digital 
equipment and processing systems required in the above system.