DVR90: Danish Vertical Reference 1990 Explanation: New reference level: A new reference level for maps is introduced in week 22 of 2002. The new level is called DVR90 (Danish Vertical Reference 1990). The new level replaces the old system of DNN. The name of DVR90 has been chosen to avoid confusion with the name DNN of the old height system. The new level is situated 10 cm above DNN. The vertical distance between DVR90 and MLWS, the chart datum for nautical charts, is 82 cm. The change is introduced in week 22 of 2002 by the Danish Coastal Directorate (KDI), the Danish Meteorological Institute (DMI) and the Royal Danish Administration of Hydrography and Navigation (FRV). The Port of Esbjerg is following in the same week. Later the local communities will follow. The new system is a general ajustment of the danish height system and is the outcome of the third Danish precise levelling performed around 1990 by the National Survey and Cadastre (KMS) and the sea level observations performed by the DMI since the early 1890's. The third precise levelling was nessessitated by steadily increasing inaccuracies in the old height system. The DVR90 is related to the mean sea level measured by the DMI in a 100-year period in 10 danish ports among which the Port of Esbjerg. The DVR90 is situated 4,6 cm below the local mean sea level (1990). The MLWS is situated 86,8 cm below the local mean sea level. This gives a height difference between DVR90 and MLWS of 82,2 cm, for practical purposes rounded off to 82 cm. The height difference between DVR90 and the old system of DNN is not constant all over the country. In Esbjerg the difference is 10,4-10,5 cm. For practical reasons a 10 cm difference is chosen.