2 Description Directory for EOV Projection System

Name:
EOV
Egységes Országos Vetületi rendszer
(Uniform National Projection system).
Description:
The EOV is a plane projection system used uniformly for the Hungarian civilian base maps and, in general, for spatial informatics. (Base maps: 1:1000, 1:2000, 1:4000 large scale maps for cadastre and 1:10.000, 1:25.000, 1:100.000 topographic maps.)
Geometric classification:
Conformal cylindrical projection in transversal position.
Date of introduction:
1972-1975
Parameters:
Reference surface:
The IUGG GRS 1967 reference ellipsoid (Geodetic Reference System of International Union of Geodesy and Geophysics, 1967):
a = 6 378 160.000 m
b = 6 356 774.516 m
Ellipsoidal geographic coordinates: ,
Projecting sphere:
A Gauss-sphere fitted to reference ellipsoid at the normal parallel.
It is used for Gauss-sphere:
its radius: R = 6 379 743.001 m
and its spherical geographic coordinates: ,
Normal parallel:
Defined as average of latitudes for Hungary, with ellipsoidal and spherical latitudes below
= 47°10'00.0000"
= 47°07'20.0578"
Origin of geographic coordinates:
The Equator and the Greenwich meridian
Origin of projection:
A point on the meridian of site "Gellérthegy":
= 47°06'00"
= 0°0'0"
the plane coordinates as
xo = 0.0 m
yo = 0.0 m
and by computing the ellipsoidal geographic coordinates:
= 47°08'39.8174"
= 19°02'54.8584"
Origin of EOV plane coordinates:
Origin of the EOV plane coordinates is moved to South-West with respect to origin of projection such that all possible EOV coordinates be positive for Hungary:
XEOV = x + 200 000.000 m
YEOV = y + 650 000.000 m
Projection zones:
A single cylindrical zone covers the area of Hungary in East-West direction.
Scale factor: mo = 0.99993
Linear distortion:
Along the y axis:-7 cm/km
North of Hungary:+26 cm/km
South of Hungary:+23 cm/km

Area distortion:
Along the y axis:-1.4 m2/ha
North of Hungary:+4.5 m2/ha
South of Hungary:+4.5 m2/ha

Formulas for computations (detailed see in Annex):

  1. First case: From IUGG GRS 1967 ellipsoid to EOV
    • ( , ) - ( , ) and ( , ) - (XEOV , YEOV)
    • From ellipsoid to the best fitting Gauss-sphere
    • From the best fitting Gauss-sphere to EOV plane
  2. Second case: From EOV to IUGG GRS 1967 ellipsoid
    • From EOV to the best fitting Gauss-sphere
    • From best fitting Gauss-sphere to the ellipsoid
Source of information: MÉM OFTH, 1975; (see Chapter 8).
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