Y-Gerät (navigation)
Encyclopedia
Y-Gerät also known as Wotan, was a radio navigation
system used by the Luftwaffe
in World War II
to aid bomber
navigation
. It was preceded by the X-Gerät system.
As the British slowly gained the upper hand in the Battle of the beams
, they started considering what the next German system would be like. With the standard beam systems clearly no longer of any use, some sort of entirely new system would have to be developed. It was thought that if they could defeat this new system, whatever it was, very quickly, the Germans would give up on the whole idea in frustration.
They soon started receiving intercepts referring to a new device known as Y-Gerät, which was also sometimes referred to as Wotan. R.V. Jones
had long realized that the Germans used code names that were far too literal. Asking around he learned that Wotan was the name of a one-eyed God. Based on nothing more than this, he assumed that Y-Gerät used a single beam. From this they thought up systems that could use a single beam, and concluded that Wotan would have to be based on a distance-measurement system. Perhaps shockingly, the guess was exactly correct.
Y-Gerät used a single narrow beam from the ground station pointed over the target, broadcasting a series of "pulse
s". A new piece of equipment in the bomber was required for the system to work; it received the pulses from the beam and immediately re-broadcast them, where they were picked up at the original station. By listening for the return pulses, the distance to the plane could be calculated with fairly good accuracy. The planes did not have to "fly the beam", ground controllers would plot the position of the plane and give instructions over radio to correct their path. A downside was that only one plane could be guided at once.
The British were ready for this system even before it was used. Fortuitously, the system operated on the same 45 MHz frequency as the BBC
's dormant Alexandra Palace television station. Using it to broadcast random "return" pulses, the German ground stations received several pulses for every one sent, and had no idea which was the "real" one. They gave up on this system after only a few small raids, considering the British to be "way ahead" and any further radio navigation systems hopeless.
Y-geräte were also used to locate and guide German fighter planes intercepting allied bombers. The system could establish direction and distance, thus location, of a fighter and use the same radio signal for two-way voice communications. Over a dozen of these systems were located near Fliegerhorst Deelen
.
Radio navigation
Radio navigation or radionavigation is the application of radio frequencies to determine a position on the Earth. Like radiolocation, it is a type of radiodetermination.The basic principles are measurements from/to electric beacons, especially...
system used by the Luftwaffe
Luftwaffe
Luftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1935 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956....
in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
to aid bomber
Bomber
A bomber is a military aircraft designed to attack ground and sea targets, by dropping bombs on them, or – in recent years – by launching cruise missiles at them.-Classifications of bombers:...
navigation
Navigation
Navigation is the process of monitoring and controlling the movement of a craft or vehicle from one place to another. It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks...
. It was preceded by the X-Gerät system.
As the British slowly gained the upper hand in the Battle of the beams
Battle of the beams
The Battle of the Beams was a period early in the Second World War when bombers of the German Air Force used a number of increasingly accurate systems of radio navigation for night bombing. British "scientific intelligence" at the Air Ministry fought back with a variety of increasingly effective...
, they started considering what the next German system would be like. With the standard beam systems clearly no longer of any use, some sort of entirely new system would have to be developed. It was thought that if they could defeat this new system, whatever it was, very quickly, the Germans would give up on the whole idea in frustration.
They soon started receiving intercepts referring to a new device known as Y-Gerät, which was also sometimes referred to as Wotan. R.V. Jones
Reginald Victor Jones
Reginald Victor Jones, CH CB CBE FRS, was a British physicist and scientific military intelligence expert who played an important role in the defence of Britain in -Education:...
had long realized that the Germans used code names that were far too literal. Asking around he learned that Wotan was the name of a one-eyed God. Based on nothing more than this, he assumed that Y-Gerät used a single beam. From this they thought up systems that could use a single beam, and concluded that Wotan would have to be based on a distance-measurement system. Perhaps shockingly, the guess was exactly correct.
Y-Gerät used a single narrow beam from the ground station pointed over the target, broadcasting a series of "pulse
Pulse (signal processing)
In signal processing, the term pulse has the following meanings:#A rapid, transient change in the amplitude of a signal from a baseline value to a higher or lower value, followed by a rapid return to the baseline value....
s". A new piece of equipment in the bomber was required for the system to work; it received the pulses from the beam and immediately re-broadcast them, where they were picked up at the original station. By listening for the return pulses, the distance to the plane could be calculated with fairly good accuracy. The planes did not have to "fly the beam", ground controllers would plot the position of the plane and give instructions over radio to correct their path. A downside was that only one plane could be guided at once.
The British were ready for this system even before it was used. Fortuitously, the system operated on the same 45 MHz frequency as the BBC
BBC
The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...
's dormant Alexandra Palace television station. Using it to broadcast random "return" pulses, the German ground stations received several pulses for every one sent, and had no idea which was the "real" one. They gave up on this system after only a few small raids, considering the British to be "way ahead" and any further radio navigation systems hopeless.
Y-geräte were also used to locate and guide German fighter planes intercepting allied bombers. The system could establish direction and distance, thus location, of a fighter and use the same radio signal for two-way voice communications. Over a dozen of these systems were located near Fliegerhorst Deelen
Deelen Air Base
Deelen Air Base is a military air base in the Netherlands in the province of Gelderland...
.
See also
- Battle of the BeamsBattle of the beamsThe Battle of the Beams was a period early in the Second World War when bombers of the German Air Force used a number of increasingly accurate systems of radio navigation for night bombing. British "scientific intelligence" at the Air Ministry fought back with a variety of increasingly effective...
- X-Gerät
- Knickebein
- List of World War II electronic warfare equipment