51 
INTERNATIONAL SOCIETY FOR PHOTOGRAMMETRY AND REMOTE SENSING 
COMMI SSI ON 11 SY MPOSI UM 
SEPTEMBER 8-12,1990 
DRESDEN, GDR 
ANALPRET Computer Assisted and Controlled Plotter 
for Teaching and Interpretation 
M. G. Gerencser, Prof. Dr. 
College for Surveying and County Planning 
Szekesfehervar, Hungary 
Introduction 
If the technical niveau of eastern and western 
photogrammetric laboratories at the Universities are compared 
the differences are sometimes shocking. Although the computer 
age knocked at the door of plotter rooms in eastern part of 
Europe in form of cheaper PC’s as well, the analytical 
plotters remain unaccessible for most of them because of 
f i nanci al s. 
The way for them stayed the digitalisation of classical 
analog plotters but first of all mono and stereocomparators 
in order to demonstrate the advantages of on line data 
reduction with application of special measuring programs. 
Our Institute has also followed this way. The good old 
Zeiss Steco 1818 Stereocomparator was attached with circular 
encoders in X, Y and PX axes having coordinate counter in a 
separate box. For the measurement and control of PY a 
stepping motor was attached to the comparator and the 
necessary control boards were built into the computer. This 
simple configuration makes it possible to enter the plotter 
coordinates into the measuring programs, realizing human 
friendly stereo vision at least for the observed homologous 
points. If the plotter is supplemented with usual graphical PC 
peripheries, the teacher can build up an expanded developing 
environment which is achievable within restricted budget. 
Our Dept of Photogrammetry went through this way and 
at last won an application for a project to build a low cost 
system, sponsored by the Remote Sensing Program Office at the 
Ministry of Industry. 
During this two years period the Analpret has been 
planned and the experimental type has been built which 
usually proceedes the prototype. 
Although the experimental stage of this modest development 
has not been finished yet, we can summarize the concept of 
this plotter and the first measuring results.