Zusammenfassung / Abstract | 5 
The tidal parameters' are several characteristic values that describe the be- 
naviour of the ocean tides. This report outlines the methodology used by the 
Tidal Information Service of the Federal Maritime and Hydrographic Agency 
(BSH) to calculate the tidal parameters operationally. Examples include the 
Mean High Water (MHW), the Mean Spring Tidal Range (MSpTH) or the Mean 
Fall Duration (MFD). 
The calculation is based on observed water level data. These are analysed 
using a special procedure in order to describe only the tidal contribution to the 
total water level: The analysis of the semi-monthly inequality. 
The theory behind the semi-monthly inequality is presented and the modelling 
of the observed data is described. A set of about 30 tidal parameters is deter- 
mined from the results of the analysis. 
Subsequently, the temporal courses of some tidal parameters at 15 tide gauge 
jocations are presented (only in German). For the Mean High Water and Mean 
Low \WMater, the data are compared with the corresponding mean values? 
‘Mittleres Tidehochwasser” and “Mittleres Tideniedrigwasser” according to 
DIN 4049-3. It can be seen that the tidal parameters and the mean values show 
similar trends in the period from 1988 to 2024, with the mean values being up to 
4 cm higher on average and subject to greater fluctuations than the correspond- 
ing tidal parameters. 
Key words: 
Tides, astronomical tide, tidal parameters, tidal constants, semi-monthly 
inequality, tide tables, Mean High Water 
A literal translation ofthe German term “Gezeitengrundwerte“ is “tidal base values“. The term can also be translated as “tidal 
sonstants" according to the IHB Special Publication No. 28 “Vocabulary Concerning Tides“ (1932). However, there is a risk of 
sonfusion with the term “harmonic constants“ which is used in harmonic tidal analysis. Here, we choose the more general translation 
‘tidal parameters“. In particular for the heights, the expressions “Tidal Levels“, “Tidal Datums“ or “Tidal Planes“ are also established. 
2 In German: “Tidekennwerte*“