Normalhöhennull

Normalhöhennull (German pronunciation: [nɔʁmaːlˈhøːənˌnʊl], "standard elevation zero") or NHN is a vertical datum used in Germany.

The reference height is a geodetic, fixed point on the New Church of St. Alexander at Wallenhorst in the German state of Lower Saxony.

The geopotential height of this point was calculated in 1986 as part of the United European Levelling Network (UELN), based on the Amsterdam Ordnance Datum.

The elevations differed — depending on location — by 0.06 to 0.16 m. As a result of new measurements as part of the changeover, however, variations of 0.59 m (Zugspitze) have surfaced.

[3] At the beginning of 2013 most of the federal states (except Berlin, Thuringia and Saxony-Anhalt) had complete coverage by the new digital topographic mapping at 1:25,000 scale (DTK).