Local Swiss reference frames

Local reference frames are adapted to the special requirements of a given region (e.g. Switzerland) and should therefore only be used in that particular region. The following local frames are used in the New National Survey.

LV95: New national control network 1995

(in the renewed Swiss reference system CH1903+)

Three-dimensional frame based on the same control points as CHTRFxx. It will serve as the basis for modern survey applications and the official cadastral survey in the future. The exact transformation, CHTRF98 <-> LV95, is guaranteed.

LHN95: National vertical network 1995

(in the renewed Swiss reference system for height LHN95)

The potential-theoretically rigorous height reference frame of the new national survey, LV95, is based on precise levelling data (from 1902 until today), with the orthometric heights from the geoid model, CHGeo2004. The height reference is the orthometric height of the fundamental point in Zimmerwald. LHN95 will not be used in cadastral surveying in the near future. The exact height transformation, CHTRF2004 <-> LHN95, is guaranteed.

Old national survey

The old national control survey is based on the following local reference frames.

LV03: National survey 1903

(in the old reference system CH1903)

Reference frame based on the triangulation 1st - 3rd order .These were established in 1903 and regularly renewed and updated. The official heights are determined from the reference frame, LN02. The densification by 4th order triangulation networks and other control networks of cadastral surveying is still the basis for most surveying activities, maps, plans and GIS. The accuracy between neighbouring points is in the centimetre range. However, the existing distortions (up to 1.6 metres) only permit limited absolute positioning in Switzerland. Direct coordinate transformation, LV95 <-> LV03, is guaranteed by «CHENxy06» dataset throughout Switzerland with an average precision of +/- 3 centimetres.

LN02: National precise levelling 1902

(in the old reference system for height LN02)

The official reference frame for height based on the «Nivellement de Précision» by the Swiss Geodetic Commission (1864-1887) and the new observations and measurements of the national levelling network from 1902 until today, without taking gravity into account. The reference frame indicates a good level of internal accuracy, but there are distortions in the decimetre range. Only an approximate direct height transformation, LHN95 <-> LN02, is possible.


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