print preview

LN02

The Swiss national levelling network (LN02), dating back to the 19th century, was conceived in 1902 with the definition of the Swiss height system. The first measurement of the network took place between 1903 and 1933, and as of 1943 it was remeasured for the second time. The reference point for the height measurements is the «Repère Pierre du Niton» in Geneva, with a height of 373.6 metres.

This network is the origin for most height calculations in Swiss maps and for all surveys carried out in Switzerland. It comprises 18 primary loops and additional secondary lines with a total of around 8000 bench marks (bolts) placed 1 to 2 kilometres apart along the main roads in Switzerland. The heights of these bench marks are the official heights (without gravity reduction) for Switzerland and are available in the form of continually revised lists.

The repeated measurements of the national levelling network have shown a relative uplift of the Alps of up to 1.5 millimetres a year with respect to the Central Plateau. Therefore the (static) values which have been in place up to today are no longer representative in national surveying. Furthermore, disregarding the effects of gravity results in systematic differences to a potential-theoretic rigorous height system. For these reasons it was decided to establish the national vertical reference system LHN95.

The Swiss national levelling network
The Swiss national levelling network


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

Federal Office of Topography swisstopo

Seftigenstrasse 264
P.O. Box
3084 Wabern

Map

Show map