Seetakt: Difference between revisions

|image = Large Seetakt <!--withoutCoastwatcher [[Image:radar illustration...]] syntax-->png

|country = [[Germany]]

In 1928 Hollmann, von Willisen and [[Paul-Günther Erbslöh]] started a company called[[Gesellschaft für elektroakustische und mechanische Apparate]] (GEMA). In the autumn of 1934, GEMA built the first commercial radar system for detecting ships, similar to a system developed by [[History_of_radarHistory of radar#Christian_HChristian H.C3.BClsmeyer|Christian Hülsmeyer]]. Operating in the 50  cm range it could detect ships up to 10  km away. This early version of the system only provided a warning that a ship was in the general vicinity of the direction the antenna was pointed, it did not provide accurate direction or any sort of range information. The purpose was to provide an anti-collision system at night, in fog, and other times of limited visibility.

By order of the German navy, in the summer of 1935 they developed a pulse radar with which they could spot the cruiser [[German_cruiser_KönigsbergGerman cruiser Königsberg|''Königsberg'']] at a distance of 8&nbsp;km, with an accuracy of up to 50&nbsp;m, enough for gun-laying. The same system could also detect an aircraft at 500 m altitude at a distance of 28 &nbsp;km.<ref name="eoportal">[http://www.eoportal.org/documents/kramer/History.pdf Earth observation portal, text on History of Earth observation (Kramer), chapter 1.2. Decadal survey, p. 81 (PDF)] {{webarchive|url=https://web.archive.org/web/20070728201749/http://www.eoportal.org/documents/kramer/History.pdf |date=2007-07-28 }}</ref><ref name="fgan4">[http://www.100-jahre-radar.de/index.html?/gdr_4_funkmesstechnik.html Radio measurement technology in Germany on www.100-jahre-radar.de, from a lecture of Dr. Wolfgang Holpp, EADS, 2004]</ref> The military implications were not lost this time around, and construction of land and sea-based versions took place as ''[[Freya radar]]'' and ''Seetakt''. The navy's priority at that time was ranging. Detecting targets and obstacles by night or in bad weather were secondary objectives. Actually using it for gun laying, like the [[Würzburg radar]] developed for the German army, was initially not a priority for the ''Kriegsmarine''.<ref name="vectorsite">[{{Cite web
|url=http://www.vectorsite.net/ttwiz7.html#m4
|title=Early German radars: SEETAKT, FREYA, WUERZBURG
(engl |url-status=dead
|archiveurl=https://web.)]archive.org/web/20060811050443/http://www.vectorsite.net/ttwiz7.html#m4
|archivedate=2006-08-11
}} An Open Source for this text on [http://www.vectorsite.net/index.html Greg Goebel / In The Public Domain]</ref>

These early-model Seetakt systems were followed in 1939 by a modified version known as ''Dete 1'', operating between 71 and 81.5 cm [[wavelength]] (368 to 390 MHz) at 8 kW peak and a [[pulse repetition frequency]] of 500  Hz. Maximum range against a ship-sized target at sea was up to {{convert|22022.0|km|mi|sp=us}} on a good day, though more typically half that. Performance was otherwise similar to the earlier system, with a range accuracy of about 50 m. This was considerably more accurate than the guns they ranged for, which typically had spreads of over 100 m. It was also much better than the typical optical rangefinding equipment of the era, which would typically be accurate to about 200 m at 20,000 m, albeit some German optical rangefinders were reportedly capable of 40-50 m accuracy at that range, which helps to explain why the Germans continued to rely on optics as their primary maritime range finding equipment for several years into the war.

[[Category:World War II German electronicsradars]]

[[Category:World War IINaval radars]]

[[Category:SeaGerman radarsinventions of the Nazi period]]