LV95: National survey 1995

(in the renewed Swiss reference system CH1903+)

Three-dimensional static reference frame based on the same control points as CHTRFyyyy. LV95 has been the official reference frame for surveying since 2017.

LHN95: National vertical network 1995

(in the Swiss height reference system LHN95)

The potential-theoretically rigorous height reference frame of the 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. As before, Switzerland’s official height reference frame is LN02. The height transformation from LN02 to LHN95 and the European height reference frame EVRF is guaranteed by swisstopo.

Old national survey

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

LV03: National survey 1903

(in the old Swiss 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. LV03 was Switzerland's official reference frame until 2016. In accordance with Article 53, paragraph 2, Geoinformation Ordinance, LV03 was valid until 31 December 2020 for geodata that are not defined as official reference data. The LV03 reference frame had a high level of local accuracy in the centimetre range. But it was only suitable to a limited extent for national absolute positioning due to the existing distortions (up to 1.6 metres). 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 Swiss height reference system 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. Nonetheless, LN02 remains the official Swiss height reference frame. Height transformation from LN02 to LHN95 is guaranteed by swisstopo.