Freya radar

One of the first developments of the Radar S in Germany is the early radar of alarm Freya , named according to the Scandinavian goddess Freya. More than one thousand of specimens were installed during the Second world war. There exists also a version developed for the marine , under the name of Seetakt.

Development

The first tests of what will become the early radar of alarm Freya take place in the first months of 1937. The first delivery of an operational station to the Navy by the firm GEMMATED (Gesellschaft für Elektroakustische und Mechanische Apparate = Société of equipment electroacoustics and mechanics) takes place in 1938. Apparently the development of the radars in Germany is definitely priority than it will be to it the case a little later in Great Britain. The Freya radar is however already much more advanced from the technical point of view than its British equivalent Chain home. It uses a Wavelength of 1,2 m, whereas Chain home functions over a wavelength of 12 Mr. Ceci increases in a drastic way the resolution of Freya, like his capacity of target detection much smaller, it also decreases the obstruction of the antennas.

Because of the cost of its construction, there are at the beginning of the war only eight apparatuses in service, which can provide only one cover very limited of the territories to monitor. Of simpler, but more inclined construction with the errors, the British radar Chain Home is much faster to install than the Freya system, so that the whole of the system Chain Home is completely operational at the time of the Bataille of England.

Technique

Later, during the war, Freya is exploited on the field of frequency of 120 and 130 MHz (of 2,3 with 2,5 m), with an impulse of 3 µs, a power peak of 15 with 20 kw, and a repetition rate of the impulses of 500 Hz. It has a maximum range of 160 km, but it is unable to determine with precision the altitude of the detected planes. In that, it is lower than Chain Home, but it can swivel in all the directions (radar all Azimut S), and can be moved.

Implementation

The first success noted dated December 18th, 1939, where an attack of day by 18 bombers Vickers Wellington of RAF is detected by two Freya apparatuses with 113 km of distance, and where air hunting can be directed on the bombers by radio. Only half of Wellington return to Great Britain without damage. This performance leaves near the Luftwaffe such an impression that as of the spring of 1940,11 Freya apparatuses are installed for the protection of the Western border of Germany. After the conquest of France in 1940, Freya apparatuses are also built along the Atlantic coast. With the increase in the British air raids, Hermann Göring entrusts to the colonel (later general) Josef Kammhuber the care to set up a more effective air defense. This led to the creation of what one will call “ Chain of Kammhuber ”, into which other Freya apparatuses are integrated. During the war, the Freya radars are sensitive to the disturbances due to the lâchers of spangles of jamming, which makes them still usable for early alarm, but much less for the control of hunting. Freya will be often used, on the other hand, of connection with the radars of fire control system, by detecting the targets with long distance, and in the “ repassant ” in Würzburg for the continuation.

Discovered

One of the first to submit a report/ratio with the British secret services on the system of Freya radars is the young lieutenant of Danish aviation Thomas Sneum, which photographs in 1941, by taking great personal risks, an installation of Freya on the Danish island of Fanø. During a spectacular flight, it brings back its negative in England. This flight is also described in the novel of Ken Follet, the flight of the Frelon ( Hornet Flight ). Its feat of arms is also evoked in the book of R.V. Jones Secret Most War (the most secret war).

See too

Radar Giant Würzburg or
of Würzburg

Sources

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