Freya Radar - Deployment and Operation

Deployment and Operation

Freya was often used in concert with the primary German gun laying radar, Würzburg Riese ("Würzburg Giant"); the Freya finding targets at long distances and then "handing them off" to the shorter-ranged Würzburgs for tracking.

Later in the war, Freya operated in the band from 2.5 to 2.3 m (8.2 to 7.5 ft) (120 to 130 MHz), with a pulse width of 3 microseconds, a peak power output of 15 to 20 kW, and a pulse repetition frequency of 500 Hz. It had a maximum range of only 160 kilometers (99 mi), making it inferior to Chain Home, nor could it accurately determine altitude, but it was a fully steerable and semi-mobile system.

Freya was first successfully used on December 18, 1939 when two stations detected an approaching daytime raid by 24 RAF Vickers Wellington bombers at a range of 113 km and guided fighter planes toward them via radio. Only half of the Wellingtons returned to Britain undamaged. This performance left the Luftwaffe so impressed that already by the Spring of 1940, eleven Freya stations were installed to guard Germany's western border. After the invasion of France in 1940, additional Freya stations were built along the Atlantic coast. When Britain started its bombing raids, Hermann Göring ordered colonel (later General) Josef Kammhuber to install an efficient air defense. This led to the so called Kammhuber Line into which then more Freya stations were integrated. In the later course of the war, Freya devices turned out to be vulnerable against chaff, which meant they could still be used for early warning but no longer for guiding fighter planes.