meters above sea

from Wikipedia, the free encyclopedia
Reference point on one of the two Neptune stones in Geneva

Meters above sea level ( m above sea level ) is the name given to heights above sea level in Switzerland . The Swiss height system and this name are also used in the Principality of Liechtenstein .

use

In Switzerland, are used as official heights leveled heights without gravity compensation from the Landesnivellement 1902 (LN02). The Repère Pierre du Niton serves as the starting point for the Swiss mountain network ( fundamental point ) . Its height was derived from the mean level in Marseille and rounded to 373.6 m.

Since the Repère Pierre du Niton was inaccurately determined at 376.86 m in 1845, heights that refer to this "old horizon" (for example in the Siegfried map and Dufour map ) are 3.26 m higher than today's official values. The Swiss heights are 6 to 75 mm higher at the border than the Austrian heights above the Adriatic .

Since the potential for gravity cannot be neglected for applications with high accuracy requirements, a height reference with orthometric heights was created with the 1995 state height network (LHN95) . The height of the new Zimmerwald reference point was chosen so that the Repère Pierre du Niton maintains its current height. The heights of the LHN95 differ from the LN02 heights by up to 50 cm. However, due to the risk of confusion when changing the height systems, the introduction of the new heights for official cadastral surveying has not been introduced.

Due to the use of different reference systems in the neighboring countries, the definition of the reference system is particularly important for cross-border projects.

See also

Web links

Individual evidence

  1. ↑ geo.admin.ch - starting point for height measurements
  2. ↑ Land surveying - Civil Engineering Office - Liechtenstein State Administration
  3. ↑ Starting point for height measurements. swisstopo
  4. ↑ LN02. swisstopo
  5. ↑ Map with height differences from the Federal Office for Metrology and Surveying
  6. ↑ LHN95. swisstopo
  7. ↑ VD brochure LV95 d.indd. ( Memento of November 26, 2007 in the Internet Archive ) (PDF; 3.4 MB)
  8. ↑ Planning margin : Rhine bridge with stairs . Mirror online