Description of CRS - SK_S-JTSK / KROVAK
AttributeEntry
CountrySlovak Republic
Country identifierSK
CRS identifierSK_S-JTSK / KROVAK
CRS alias
CRS valid areaCzech Republic / Slovak Republic
CRS scopeCoordinates of Uniform Trigonometrical Cadastral Network
CRS remarks
Datum identifierS-JTSK
Datum alias
System jednotne trigonometricke site katastralni (System 
of Uniform Trigonometrical Cadastral Network) 
Datum typegeodetic
Datum anchor point
Austria, Hermannskogel, Habsburgwarte,
Lat = 48°16'15.2900" N,
Lon = 16°17'41.0600" E
Datum realization epoch1920-1957
Datum valid area
Czech Republic / Slovak Republic
Datum scope
Datum remarks
Prime meridian identifierGreenwich
Prime meridian greenwich longitude
Prime meridian remarks
Ellipsoid identifierBessel 1841
Ellipsoid aliasBessel
Ellipsoid semi major axis6 377 397.155 m
Ellipsoid shapetrue
Ellipsoid inverse flattening299.15281285
Ellipsoid remarks
Coordinate system identifierKROVAK
Coordinate system typeprojected
Coordinate system dimension2
Coordinate system remarks
Coordinate system axis nameX / southing
Coordinate system axis directionSouth
Coordinate system axis unit identifiermetre
Coordinate system axis nameY / westing
Coordinate system axis directionWest
Coordinate system axis unit identifiermetre
Operation identifierKROVAK
Operation valid areaCzech Republic / Slovak Republic
Operation scopethe reference area is represented by the cone extended to the plane
Operation method nameOblique Conformal Conic Projection
Operation method name alias
Krovak's Projection
Operation method formula
Kostelecky, Jan; Research Institute of Geodesy, Topography 
and Cartography, CZ-25066 Zidby 98: Description of a 
procedure of transformation between geodetical coordinates 
and planar (cartographic) coordinates in KROVAK projection 
- or - 
Projection equations for the calculation of coordinates X, 
Y and meridian convergence C from given geographic 
coordinates B and L, In: Danis, M.; Valko, J.: Matematicka 
kartografia. Edicne stredisko STU.  Bratislava 1998, p. 
134- 149. 
Operation method parameters number18
Operation method remarks
Coordinate system is rectangular. Its beginning is located 
at the vertex of the cone.  The axis X is the image of 
longitude 42°30' eastwards of Ferro (24°50' E wrt 
Greenwich) with the positive branch oriented to the south. 
The axis Y is perpendicular to it  and its positive branch 
is oriented to the west. The vertex of the cone is at the 
meridian 42°30' eastwards of Ferro (24°50' E wrt 
Greenwich) and northwards of the parallel Lat=48°15' N by 
1298039.0046 m and its axis goes through the centre of the 
Earth. 
Operation parameter nameprime geographic latitude on Bessel ellipsoid
Operation parameter value
49°30' N
Operation parameter remarksfor this latitude were derived invariables for conform projection of Bessel ellipsoid to Gauss sphere
Operation parameter nameprime geographic latitude on the Gauss sphere
Operation parameter value
49°27´35.846255" N
Operation parameter remarksvalue prime geographic latitude on the Gauss sphere corresponds to prime geographic latitude on Bessel ellipsoid
Operation parameter nameprime meridian on Bessel ellipsoid / longitude of intersection of central cartographic parallel and fundamental meridian on the Bessel ellipsoid
Operation parameter value
42°30' E wrt Ferro
Operation parameter remarkson this meridian is located the beginning of the coordinate system JTSK
Operation parameter nameprime meridian on the Gauss sphere / longitude of cartographic pole on the Gaussian sphere
Operation parameter value
42°31´31.41725" E wrt Ferro
Operation parameter remarksprime meridian on the Gauss sphere corresponds to prime meridian on Bessel ellipsoid
Operation parameter namescale factor of central cartographic parallel
Operation parameter value
0.9999
Operation parameter remarks
Operation parameter namefalse southing
Operation parameter value
0 m
Operation parameter remarks
Operation parameter namefalse westing
Operation parameter value
0 m
Operation parameter remarks
Operation parameter namemultiple invariable
Operation parameter value
1.000597498372
Operation parameter remarksit serves for the calculation of spherical geographic coordinates on the Gauss sphere
Operation parameter nameintegration invariable
Operation parameter value
1.0034191640
Operation parameter remarksit serves for the calculation of spherical geographic coordinates on the Gauss sphere
Operation parameter nameradius of the Gauss sphere
Operation parameter value
6380703.61054 m
Operation parameter remarksBessel ellipsoid is projected on Gauss sphere
Operation parameter nameradius of reduced Gauss sphere
Operation parameter value
0.9999 * radius of the Gauss sphere
Operation parameter remarksthe reduced Gauss sphere is conformly projected on the conic area
Operation parameter namespherical geographic latitude / latidude of cartographic pole on the Gaussian sphere
Operation parameter value
59°42'42.69689" N
Operation parameter remarks
Operation parameter namespherical geographic longitude of cartographic pole
Operation parameter value
spherical geographic longitude of cartographic pole is 
identical with prime meridian on the Gauss sphere 
Operation parameter remarks
Operation parameter namepolar distance of the cartographic pole on the Gauss sphere
Operation parameter value
complement from spherical geographic latitude to 90° N
Operation parameter remarks
Operation parameter nameprime cartographic parallel / latitude of central cartographic parallel on the Gaussian sphere
Operation parameter value
78°30' N
Operation parameter remarksin this parallel the cone flanks the reduced the the Gauss sphere
Operation parameter nameradius of the image of prime cartographic parallel
Operation parameter value
1298039.00463 m
Operation parameter remarks
Operation parameter namelatitude of intersection of central cartographic parallel and fundamental meridian on the Bessel ellipsoid
Operation parameter value
48°15' N
Operation parameter remarks
Operation parameter namewidth of zone between cartographic parallels
Operation parameter value
3°30'
Operation parameter remarks