"dM e 
metry. The most common is the line-drawn manuscript which is used as 
an input to conyentional cartographic processes for production of maps. 
Here the photogrammetric output is only an intermediate storage of 
information. With respect to the developments in digital cartography, 
where digital information processing and computer-aided editing is 
being applied, and where the final line-drawn map is generated auto- 
matically by the digital controllers of automatic plotters, the photo- 
grammetrically derived line-drawn manuscript is not a satisfactory solu- 
tion owing to its incompatibility with the rest of information proces- 
sing. (Digitizing of such manuscripts on digitizing tables has two 
obvious shortcomings: the retracing of all the features that were 
already traced in the stereo-model and the low accuracy of manuscripts 
that are at least one order of magnitude below the accuracies achievable 
even on analog instruments.) Thus, direct digitizing of information for 
digital cartography is the rational technique to be applied not only 
because it preserves the accuracies but also because the digital storage 
medium is compatible with the equipment used for subsequent processing. 
It is conceivable that due to the declining interest in intermediate 
graphic outputs, the analytical instruments in digital cartographic 
systems will not have a plotting table but only temporary graphic dis- 
plays (e.g. CRT, position verifier). 
Otherwise, for applications where on-line graphical plotting 
is required, it should be noted that the addressing capabilities of the 
feedback positioning devices of the table are the same as those that 
control the photo-stages (except for the lower accuracy of positioning). 
Consequently the plotting of any quantity derived from model coordinates 
can be done in any desired reference system. A detail of interest may 
be the procedure for orientation of the manuscript. For instance, the 
manuscript can be placed on the table in an arbitrary way. The plotting 
table coordinates of control points marked on the manuscript are 
recorded as well as the coordinates of the corresponding control points 
in the model space. From these two sets of observations, the parameters 
for conformal or affine (or any other) transformation are determined by 
least square adjustment. This example clearly indicates the complete 
flexibility in regard to the choice of reference systems in which the 
plotting may take place. 
5.2. Numerical output 
  
À typical example of photogrammetric numerical output is the 
result of digitizing the information needed for the production of maps 
(planimetric detail, contours, spot elevations, etc.) in discrete or 
quasi-continuous time or space-dependent modes. It consists of ordered 
sets of coordinates and identifiers on a storage medium. This general 
case of photogrammetric digitizing is becoming one of the standard out- 
puts of photogrammetric processing, owing to the growing requirements 
imposed on photogrammetry by other information systems such as digital 
cartography, numerical cadastre and data banks of geocoded information. 
The basic problem in this type of digitizing arises from the inability 
of the operator to interpret, check and correct directly the digital 
records. In this respect the analytical instruments are ideally suited 
for incorporation of auxiliary devices for graphical display of digital 
records. One of them is the interactive cathode-ray tube graphic dis- 
play. An analytical instrument interfaced with such a display and 
having the proper software support represents a remarkable digitizing