Swiss reference systems

With national survey LV95 a global (CHTRS95) and a local (CH1903+) system were defined in Switzerland which have functioned as the official Swiss reference system since 2017. The latter replaces the old local reference system (CH1903), which formed the basis for surveying in Switzerland for more than a hundred years.

CH1903+: Official Swiss reference system

Geostation Zimmerwald 1
Geostation Zimmerwald

The reference system for the Swiss national survey was defined in 1995 on the basis of satellite measurements at more than 200 LV95 reference points. CH1903+ uses the same ellipsoid (Bessel 1841) as CH1903. The fundamental point of reference system CH1903+ is Zimmerwald geostation. The positioning of the system is derived directly from CHTRS95 by translation (3 shifts). The map projection (Swiss Grid) is identical to CH1903. The fundamental point (Zimmerwald geostation) also serves as the point of origin for the height. Its orthometric height was defined as H0 = 897.9063 metres, so that for the “Repère Pierre du Niton” in Geneva the value of 373.6 metres is obtained.

CH1903: Reference system of the old national survey 1903

Old observatory, Bern
Old observatory, Bern

The old reference system (CH1903) was defined and introduced in 1903 based on reference ellipsoid Bessel 1841 fixed in position and orientation to the old fundamental point (old observatory in Bern) and the Swiss oblique conformal cylinder projection (Swiss Grid). CH1903 also defines the old official height system for which the “Repère Pierre du Niton” in the port of Geneva serves as the point of origin with a height of 373.6 metres.

CHTRS95: Swiss Terrestrial Reference System 1995

The global reference system for the Swiss national survey LV95 is identical to the European reference system ETRS89 as of 1 January 1993. Like its European counterpart, CHTRS95 uses reference ellipsoid GRS80 and Universal Transverse Mercator (UTM) as projection.


Federal Office of Topography swisstopo Seftigenstrasse 264
P.O. Box
3084 Wabern
Tel.
+41 58 469 01 11

E-mail


Relevant authority

Geodesy and Federal Directorate of Cadastral Surveying
E-mail


Print contact

Federal Office of Topography swisstopo

Seftigenstrasse 264
P.O. Box
3084 Wabern

Map

Show map