| Description |
The Normaal Amsterdams Peil (NAP) is the reference level for heights in the Netherlands. The NAP is a dense network of about 35000 benchmarks, of which about 400 are deeply founded underground benchmarks. On the one hand, the benchmarks form the basis for the geodetic network in the Netherlands, and on the other hand they form an important basis for the initial height determination and stability monitoring of all civil infrastructure. The benchmarks are measured using optical levelling. |