Geography Reference
In-Depth Information
Office Experimental Institute
around 1978. At that time, the organisations of the
Hungarian cartography did not use computers, but the organisations of the tele-
communication wanted to solve their problems by using IT supported planning
methods. For the purpose of the Hungarian Post Office, a lower resolution database
was suitable, although the resolution was not comparable to a real digital carto-
graphic database. The base of the database was the 1:25,000 scale civil topographic
maps. As mentioned previously, these maps were classified; therefore, the Hungar-
ian Post Office Experimental Institute had to ask the help of the civil state cartog-
raphy. With their contribution the institute finally got the permission from the
Ministry of Defence.
The equidistance of the 1:25,000 scale maps was 5 m, which would allow the
interpolation of heights within less than one metre, but due to the poor digital
storage capacity of the time the operators read the heights with one metre
precision only.
In this special project, the map sheets were only used for interpolating the
heights in grid points, although other factors on a terrain would also influence the
wireless telecommunication. However, it was not possible to determine these
factors were in proper accuracy from the paper map sheets. For the general
calculations of the microwave and very high frequencies the 200-m-grid was
appropriate, but it was a compromise between the special needs of the Hungarian
Post Office Experimental Institute and the IT opportunities of the time (Fig.
1
)
(Ko
ยด
s
1996
).
The First Digital Map Production
The first GIS software applications became available in Hungary in the middle and
at the end of the 1980s. Although this was the last decade of the cold war period, the
Fig. 1 Digital terrain model based on DTM-200, printed by contemporary plotter
