Kiel data up to 1992 supplied by Wasser und Schiffahrts. Nord, Kiel (auth=13). Data 1993- supplied by Bundesamt fur Seeschiffahrt und Hydrographie (BSH), Hamburg (auth=16).
Documentation added 2010-08-09
The data for Kiel-Holtenau was measured to PN = NN-500cm Normal depth of PN=500cm. Normal Null(NN)is a German datum related to levels at Potsdam near Berlin. It is similar to ODN in the UK and the NAP in Holland. It is unusual therefore that the German stations have been made RLR as it 'breaks the rules' of RLR. Data now refers to TGZ.
Documentation added 2013-01-22
Value for PHP relative to NHN is 4.995m from 12.04.2006
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