Lorenz beam

In all of these roles, the system was generically known simply as a "Lorenz beam".

This used a Lorenz beam for horizontal positioning, and a transponder for ranging.

The ground stations consisted of a set of four antennas that projected Lorenz beams in four cardinal directions.

Using Lorenz beams, Elektra allowed each signal to be narrower, so a single station could provide a number of incoming and outgoing paths, instead of just four.

In 1932, development of a new type of radio navigation system - soon known worldwide as the Lorenz beam - gave a major extension of their aircraft radio business.

Called Ultrakurzwellen-Landefunkfeuer (LEF) or, commonly, Lorenz beam, this system was sold worldwide for aircraft guidance and blind landing.

This emerged as a system generically known as a "Lorenz beam", which used three antennas and phasing techniques to produce highly directional signals only a few degrees wide.

The Germans developed the short-range Lorenz system into the Knickebein aid, a system which used two Lorenz beams with much stronger signal transmissions.

Bomber crews already had some experience with these types of systems due to the deployment of the Lorenz beam, a commercial blind-landing aid which allowed aircraft to land at night or in bad weather.

In addition the Lorenz beams were deliberately set wide enough that they could be easily picked up at some distance from the runway centreline, but this meant their accuracy at long ranges was fairly limited.

Using technology previously used for his Lorenz beam landing system, Plendl developed a system that would guide planes to their target, and which improved the accuracy of bombing at night or in poor weather conditions.

By 1937 the airport had also received new radio navigation equipment and was using Lorenz beam technology to assure the safety of landings and approaches over Warsaw during periods of poor visibility or bad weather.

The reason the Lorenz beam principle was necessary, with its overlapping beams, was because the sharpness of a beam increases approximately logarithmically with the length of the aerial array with which it is generated.

In the Second World War the Lorenz beam principle was used by the German Luftwaffe as the basis of a number of blind bombing aids, notably Knickebein ('crooked leg') and the X-Gerät ('X-Apparatus'), in their bombing offensive against English cities during the winter of 1940/41.