Estimating Map Document Content 
  
A major problem in digital mapping consequently reduces to 
transfer of line-map data from a stereo photogrammetric instru- 
ment onto a compilation sheet for pre-editing. Transforming the 
data to a computer precisely and economically for retrievable 
storage, display, change, and plotting on separation negatives 
needs to be at a quality numerically specified. Such specification 
of a Mapping System can be best defined as one which performs 
Operations on a series of documents used or created in the 
process.?? The content of map-system documents at present can 
De estimated by the magnitude of its information in bits. This 
magnitude implies the resolution, positional precision, and 
therefore quality of the documents. The major documents referenced 
are tabulated with data content defined below: 
  
Document Maximum Bits Form of Data 
(neet) (magnitude) (digitized) 
Roll of Film 9" x 9000" 1012 Facsimile 
(aerial) 
Photograph 9 x. 9" 10° Facsimile 
Control Sheet 48". x 48" 10° Vectors & Data 
(geodetic) 
Line Sheet 48" x 48" 108 Facsimile 
Name Sheet 48" x 48" 10? Vectors & Data 
Display Section 4" x 4" 104 Vectors & Data 
(12"- x.12") 
Separation Neg. 48" x 48" 109 Facsimile 
9 
l0-Color Map 48" x 48" 10 Facsimile