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For collection of information, the existing equipment components can be 
used (figure 1). Cartographic line digitisers are suitable for thematic 
mapping from single images. Operational characterictics can be improved, 
however, by using dedicated equipment which permits stereo observation 
and additional digitising of the parallaxes caused by differential 
heigbts. 
An interactive terminal and graph-image overlay sub-system improve sub- 
stantially the operational characteristics. The equipment components for 
processing and presentation of information are standard, and are there- 
fore not considered here. 
3. Software 
Software structure and modules affect decisively the versatility, 
flexibility and efficiency of a system. The structure and modules cor- 
respond to those of analytical stereoplotters, with minor differences. 
These differences concern: 
— The external orientation of single photographs, by resection or from 
aerial triangulation (some analytical stereoplotters are also provided 
with this module); 
— Image-to-DIM surface transformation, which replaces the real-time in- 
tersection of conjugate rays in analytical stereoplotters. 
— The restitution concerns merely the planimetric features; the cor- 
responding heights are a byproduct, which is usually not recorded. 
If non conventional images are used as input for AMP, additional modules 
are needed for correct image-to-DTM surface transformation. 
4. Input and output 
Description of input concerns the information and data sources, intended 
mapping mode, destination (or role) of information and data in the 
process, and their quality (figure 3). 
[ old . mono 
Images L new . stereo 
Maps 
— Sources Digital files 
Other documents 
primary 
Complete —— re-mapping 
— Mapping 
revision 
Differential —- upgrading 
thematic 
semantic 
Basic [7 metric 
INPUT — — 
  
— Destination d. Control — semantic 
L metric ! domain 
— Semantic 
— Quality FE Metric } for real input 
Fig. 3: Description scheme for the input 
The desired and/or anticipated properties of the AMP output can be 
similarly described. The main items concern the type of product, content 
of data base, form of presentation, and the output quality (figure 4). 
31