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The German Hydrographic Institute within the year 1966 
In the department Geophysics and Astronomy the spectrum analysis of 
hourly water levels of Ouxhaven delivered another 11 significant tides in 
addition to the 64 partial tides used in the harmonic analysis. According 
to an extreme values statistics of high water levels at Cuxhaven, there 
is no upper limit for storm surge water levels. The psychological-physio 
logical test of radar observers aboard ships confirmed the decrease in 
performance when ships approach one another at small intersecting angles, 
which raises the collision risk. The time signal of Elmshorn could often 
be recorded in the winter months after the revolution round the earth so 
that the velocity of propagation of electromagnetic waves could be fixed. 
The activities of the department Oceanography centred on the work 
at sea with RV "Meteor". All scientists took part in it. SRV "Gauss" per 
formed several research cruises into the North and Baltic Seas and 
participated in the international investigation of the water masses and 
the circulation distribution in the Skagerrak. In order to find out 
whether the Kieler Förde and the Lübecker Bucht are suited for the 1972 
Olympic sailing boat regatta, the G.H.I. conducted current measurements 
in these areas. Investigations of the haline discontinuity layer in the 
North Sea were completed. The measuring and recording electronics of the 
temperature recording instrument "Delphin" successfully'stood their test 
over a towing distance of more than 1,000 nm. The results of physical 
measurements along piston corer profiles shall be referred to the pro 
pagation of sound in the sediment. Measurements of the shearing strength 
on piston corer profiles permit to express the consistence of the sediment 
in numerical form. The coasts of the Federal Republic of Germany had an 
icy winter period 1965/66. 
Beside the above activities, the routine work took a great share in the 
G.H.I.: the following periodicals were issued: Winterbetonnung der deutschen 
Küstengewässer (winter buoyage of the German coastal waters); Gezeiten 
tafeln und -kalender (tide tables and calendars); Nachrichten für See 
fahrer (Notices to Mariners); Eisberichte und Eisübersichtskarten (ice 
reports and general ice.charts); Nautisches Jahrbuch (nautical almanac); 
Der Seewart; Verzeichnis der Nautischen Karten und Bücher (list of nautical 
charts and books); Jahresbericht des DHI (annual report of the G.H.I.); 
Erdmagnetische Beobachtungen (geomagnetic observations); Deutsche Hydro 
graphische Zeitschrift (German hydrographic journal); Informationen der 
hydrographischen Dokumentation (information of the hydrographic documentat 
ion). As to the Services of the G.H.I., the Nautical Warning Service 
broadcasted 2,855 notices, the Wind Effect and Storm Surge Warning Service 
promulgated 30 special warnings beside the regular morning and evening 
forecasts; the Time Service made 1,781 star observations during 74 nights 
and emitted about 8,000 precision time signals on different frequencies;