National Survey LV95
In the period from 1988 to 1995 the Federal Office of Topography swisstopo developed a national surveying system that is largely based on satellite measurement. LV95 replaces the 100-year-old national survey (LV03), based on triangulation. The fundamental point for LV95 is the geostation in Zimmerwald, near Bern.
The national survey is based on two new reference systems:
CHTRS95
The CHTRS95 global system is connected to the international and European reference systems. It includes a kinematic model and is suitable for scientific applications and demanding engineering projects.
CH1903+
The local reference system, CH1903+, is static and provides the coordinates reference system for all surveying activities. By connecting observations to the old national survey, the data from the still official reference system, CH1903, could be adopted and transformed into the new system, CH1903+.
As of 1988, the basic network LV95) was built up in smaller networks and determined with a high degree of accuracy using the satellite navigation measurement method. It consists of approximately 200 carefully chosen geodetic control points. The “absolute” accuracy of the coordinates throughout Switzerland is within 1 to 2 centimetres for the horizontal component, and 2 to 3 centimetres for the ellipsoidal height. It entered into effect as the official reference system at the beginning of 2017.
The results of the CHTRF measurement campaign showed that some regions shift by up to 1 millimetre a year, which means that the indicated accuracy of the coordinates for these regions cannot be adhered to. Work is being carried out in an effort to find a solution so that the realisation of CH1903+ can be assured without adjusting individual coordinates.
To differentiate between the LV95 coordinates in the CH1903+ system and the old LV03 coordinates in the 1903 system a seventh digit was added as a prefix to the previously 6-digit coordinates: number 1 in the north-south direction and number 2 in the west-east direction. The coordinate axes were also renamed E (east-west) and N (north-south). In the national maps, only the lettering of the coordinates in the margins was changed.

Links
- Geodetic Reference systems
- Geodetic Reference frames
- Zimmerwald geostation
- REFRAME online calculation services
- EUREF (Reference Frame Subcommission for Europe)
- EPN (EUREF Permanent Network) analysis centres
- ITRS (International Terrestrial Reference System)
- ETRS89 (European Terrestrial Reference System 89)
- IGS (International GNSS Service)
- FPDS data viewer (LV95 control points)
Documents
-
Approximate formulas for the transformation between Swiss projection coordinates and-WGS84
PDF, 4 page(s), 146 KB, English -
Formulas and constants for the calculation of the Swiss conformal cylindrical projection and for the transformation between coordinate systems
PDF, 20 page(s), 490 KB, English -
Bericht Neues «Schweizer Höhensystem» – Studie Modernisierung des Schweizer Höhenbezugssystems und -rahmens, Teil I
PDF, 95 page(s), 42 MB, German -
Rapport Nouveau système altimétrique Suisse – Étude sur la modernisation du système et du cadre de référence altimétrique en Suisse, partie I
PDF, 94 page(s), 41 MB, French
P.O. Box
3084 Wabern
- Tel.
- +41 58 469 01 11
Relevant authority
Geodesy and Federal Directorate of Cadastral Surveying