Height finder

Radio altimeter and radar altimeter is a specialized mostly ground-based radar system for two-dimensional coordinate measurement elevation angle and distance and the derived height of the located objects. Often they are also called by the common name " height finder ", which is an incorrect translation of the English Height Finder. Radio altimeter were used to measure the altitude of airborne targets in radar guidance, Waffenleit - and anti-aircraft missile systems.

As a defense against enemy aircraft in addition to its geographical position and the knowledge of the exact altitude is important. It usually worked two radars as a pair: a search radar ( with a panoramic screen) coupled to a radio altimeter ( with RHI -Scope ), whose vision devices were usually built one above the other. The antenna of a radio altimeter is pivoted to a set azimuth angle at an interval of 1 to 2 seconds mechanically up and down. The antenna pattern is a fan lying with a horizontal beamwidth diagram about 3 to 5 °, and a very narrow vertical beam width of less than one degree. The surveillance radar enabled a map- like overview around the radar site, the radio altimeter was directed to a specific target in azimuth and elevation angle and was its exact altitude measure. The disadvantage was that the radio altimeter had to be aligned by hand crank in a given side angle. The measurement of all three coordinates ( azimuth, distance, height) of a target was thus very time-consuming. At very long range radars, such as Kabina 66 number of radio altimeter type PRW- 13 or PRW -17 could be coupled.

With modern equipment mainly working as a multifunctional 3D radar of radio altimeter lost its meaning. This development can be seen nicely on the radar position of NATO on the Große Arber: In the front radome there used to be a radio altimeter AN/FPS-6, in the rear the surveillance radar. After installing the 3D radar RRP 117 radio altimeter was superfluous, the radome is used misused ever since.

• Wireless technology
• Radar