single points) can be digitized manually at an acceptable cost for the 
anticipated benefits. But complex data categories (with many curved 
lines, intersections, symbolization, or attributes) are still relatively 
expensive to digitize. 
Another trend relates to data base availability where it is necessary to 
have adequate coverage before a significant number of applications will 
emerge. Lacking a critical mass of generally available and standardized 
data, only demonstration projects with custom digitized data or projects 
with the highest perceived benefits can be justified. Some single cate 
gories of data, such as elevations and some boundaries, are in a range 
of adequate coverage, but multiple (complex and expensive) categories 
are only now being assembled. 
The lower half of figure 3 shows the trends in the two major applications 
of digital cartographic data, geographic information systems and auto 
mated cartography, for which the major advantages are claimed. I do not 
believe that either application has truly come into the cost-effective 
range of general applicability, but this is rapidly changing and success 
ful development in these two areas holds the key for the analog-to- 
digital transition of cartography. 
OBJECTIVES OF THE NMD DIGITAL MAPPING PROGRAM 
The scenario that presented itself to the NMD in planning the Digital 
Mapping Program led to the following four major objectives: 
1. Continue the preparation of conventional line maps by the most 
economic methods. 
2. Convert the large amount of existing line map data into a 
computer-compatible form. 
3. Establish a digital cartographic data base that will serve as 
a foundation for further geographic information systems. 
4. Reconfigure the conventional mapping process to take full 
advantage of automation, especially as it will influence map 
revision. 
Also, a number of secondary objectives have emerged. These include 
the preparation of a small-scale data base that can be used to prepare 
special graphics and index maps of a national scope and the development 
of some data base categories for use at intermediate scales, i.e., 
1:100,000 to 1:250,000. These primary and secondary objectives introduce 
a number of conflicting situations that require technological and pro 
gram-management solutions. 
The first objective, continuation of an economically viable conventional 
mapping program, requires that many of the well-established analog photo 
mechanical techniques of map preparation be continued. Until recently, 
at least, evaluation of completely digital raapraaking in other mapping 
organizations indicated that attempts to totally automate map prepara 
tion usually resulted in higher initial costs, and the assumed cost 
advantages in deriving other maps at smaller scales or in conducting map 
revision had yet to materialize.