Reference System

A reference system called Hungarian Datum 1972 (HD-72) was introduced in 1972 based on independent adjustment of Hungary’s astrogeodetic network. Its reference ellipsoid is the IUGG Geodetic Reference System 1967 (GRS67: a = 6378160m, b = 6356774.516m, f=1/298.247167). The HD-72 is located and oriented relatively at the terrestrial point Szõlõhegy.

Based on HD-72, Hungary established

• Uniform National Horizontal System (in Hungarian called: EOVA),

• Uniform National Height System (in Hungarian called: EOMA),

• Uniform National Mapping System (in Hungarian called: EOTR).

Projection System

A projection system for civil use called EOV (Uniform National Projection system) was introduced in 1972. The reference ellipsoid of EOV is the IUGG GRS67. Type of the projection: oblique-axis reduced (secant) cylindrical projection. The whole territory of the country is represented on one strip of cylindrical projection.

Recently, projection systems of earlier times are in use, too:

• three oblique-axis cylindrical projection systems: North, Median and South,

• stereographic projection for cadastral maps at scale 1:2880, 1:1440 and 1:720.

To meet the requirements of the domestic and international professional communities, a Description Directory of Hungarian Reference and Projection Systems has been issued in 1995 by FÖMI. The Description gives an overview on the EOV parameters, the HD-72 definition, the Hungarian vertical system and the relation of HD-72 to the WGS-72 and the EUREF-89 (WGS-84) systems. A revised version of the transformation parameters has been computed, harmonised in the frame of the EUREF WG of EuroGeographics and IAG, as well as disseminated for GI use in 2000. This version became part of the Hungarian GI standard.

Military maps and digital mapping databases are using Universal Transverse Mercator (UTM) and Lambert Conformal Conical map projections on the WGS-84 reference ellipsoid.