The defences – Air detection (II)May 29, 2017
RADAR was the acronym for Radio Detection And Ranging, with the first sets being tested by British and Germans at the same time during the early years of the 1900s.
Its combat debut was during Second World War. It was an invaluable air detection aid whenever bad weather, darkness or the enemy’s action made impossible to track and locate an incoming raid. During the next years, RAF and Luftwaffe will play “cat and mouse” in radar procedures in the ensuing Bombenkrieg.
[This picture shows the GEMA complex and buildings, where the German radar was developed located at Berlin. In 1940, more than 6,000 people worked here.]
The birthplace for the German radar was GEMA company (Gesellschaft für elektroakustiche und mechanische Apparate - “Association for Electroacoustic and Mechanical Equipment”), founded by Paul-Günther Erbslöh (1905–2002) and Hans-Karl von Willisen (1906–1966). They worked together and after left Telefunken, developed the first air warning radar system.
The installation was overrun by the Soviets in May 1945. Most of the equipment and many of the people were deported to Russia as part of the war bounty.
The first radar unit developed by GEMA in 1937 was the FuMG 403 Panoramagerät Stützpunkt (Plan Position Indicator-PPI) display radar, built in 1941 at Tremmen near Berlin (40 km west of the city) at a cost of 500,000 Reich Marks (RM). The 20 m large antenna is located in the top of the concrete tower and it rotates through 360 deg. at 6 rpm. Range is 120-300 km. The radar display station is located in the base of the tower and a PPI display. The tower was linked by landline to the headquarters of the 1st Flak Division in the Zoo’s Turm. The site was blown up after the war by the Russians.
[One of the rare known views of the Project C Panoramagerät Tower PPI.]
[A view atop of the Panorama Turm with its 20 m long beam equipped with 16 dipoles.]
From the early works on Panorama, GEMA created an advanced and more compact unit, and this would be the start of the radar net of the German defences.
[A Freya RADAR system at one of the thousand radar sites placed all over the German-occupied Europe.]
Named after the Norse Goddess Freyja, the Freya FuMG 450 was the first operational early warning radar defence system. Before the beginning of WWII, in 1938, just eight of these units had been delivered by GEMA and deployed along the German border manned by the Luftwaffe.
The early versions had a range of 60-80 km which was later increased to 120 km. Azimuth accuracy was 1.5 degrees and better. Developed from a Kriegsmarine (Germany’s war navy) radar, its lower frequency range (120-166 MHz vs 368 MHz), longer wavelength (2.5 m vs 50 cm), and longer range. It was more advanced than the British system, but more complex what it means that it was not totally readied and needs improvement when the first raids came.
Freya was first successfully used on December 18, 1939 when two stations detected an approaching daytime raid on Wilhelmshaven by 22 RAF Wellington bombers at a range of 113 km and guided fighter planes toward them via radio, downing half of the enemy’s force. This early success of radar left the Luftwaffe so impressed that Freya network was the chosen one to guard Germany’s western border.
Anyway, these radars were only able to spot and track incoming aircraft, not to determine the exact range and height.
[An RAF photograph of the Freya radar installations at Auderville, France as viewed during 1941.]
[An illustration of a German Pole Freya Radar from an US Army study after the war.]
[A Dreh-Freya radar and a FuSE 62D ‘Würzburg’ unit of the Versuchsfeld Werneuchen beim Fliegerhorst at Werneuchen-Brandenburg, some 30 km northeast of Berlin.]
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