Hungarian Reference System, HD-72, Hungarian Datum of 1972
The HD-72 is Geodetic Reference System ensuring the geodetical unity of Hungary's surveying, mapping and remote sensing activity located and relatively oriented at the Geodetic Datum Point Szőlőhegy. Its definition was made in the course of adjustment of the Hungarian Astrogeodetical Network on the ellipsoid of the reference system IUGG GRS 1967 and at the Laplace-points on the condition = minimum set up for the deflections of the vertical (where and are the values of the deflection of the vertical).
c) Reference ellipsoid:
The ellipsoid of the reference system IUGG GRS 1967 (See chapter 4.1.)
d) Datum station:
Its surface geographical (astronomical) coordinates:
Ast = 47°17'30.44" , Ast = 19°36'10.18". Surface (astronomical) azimuth of the direction from Szőlőhegy to Erdőhegy: Ast = 209°55´ 27.79".