AOD and Europe
In the creation of the European Union there was a need for a uniform height system in Europe. In order to eliminate the differences between national height systems, the countries of the European Union in the context of the REUN (Réseau Européen Unifié de Nivellement) linked their height systems together. For this new European’s height system named as EVRS (European Vertical Reference System) they chose the AOD as the zero-point (base). These developments emphasize the major importance of the AOD in international context. The EVRS is important in particular for geo scientific research.
Embarrassing discovery during the construction of a new bridge (read article)