Description of the radar set, tactical-technical characteristics
Figure 1: Antenna of Mammut-Radar
GES. FÜR ELEKTROAKUSTISCHE U.
MECHANISCHE APPARATE M.B.H.
|frequency:||120 … 135 MHz|
|pulse repetition time (PRT):|
|pulse repetition frequency (PRF):|
|pulsewidth (τ):||2 to 3.5 µs|
|peak power:||200 kW|
|average power:||8 kW|
|instrumented range:||200 km|
|range resolution:||300 m|
|hits per scan:|
The Mammut radar (FunkMeßGerät 65, FuMG 41/42) is a fixed radar with a wavelength of 2.20 … 2.50 m. The antenna is fixed with a reflector array made of wire mesh with a size of 10×30 m. It consists of four planes with 16 dipoles each. The two upper planes are the transmitting antenna, the two lower planes are the receiving antenna.
Since the antenna is not rotatable, the beam swiveling is done electronically by an “electrical compensator” as a phase shifter, which switched bypass lines into the feed line. This made it possible to slew the transmit beam in an angular range of ±55° to the main axis. For a full omnidirectional search, at least two mammoth devices were needed, which could also be constructed double-faced as a “Janus Bifrons” antenna.
The range measurement accuracy was ±300 m, a side bearing accuracy ±0.5°. The weight of the equipment was about 25 t. The Mammut device could be coupled with the “Malaja” device. This was an additional receiving system, which used the top and bottom antenna planes, thus forming a very narrow vertical diagram. An additional measurement of the elevation angle was made possible by a phase comparison between two planes.
In 1944, the Mammut radar was thus the first three-dimensional radar with a phased array antenna.