ST-68U
The ST-68U ( NATO code : Tin Shield , Russian designation: 19Ж6, Koroljeva (Queen)) is an air surveillance radar device that was originally used in the EW organization of the countries of the former Warsaw Pact . It was developed in 1981 and is still in use today in many countries of the former Eastern Bloc. It is also sold as a replacement for the Big Bird in export versions of the SA-10 system.
The ST-68U is a 3D radar with a frequency-controlled phased array antenna . With a total of four different transmission frequencies, the antenna diagram covers four different elevation angles . Due to the overlapping of the individual diagrams, the elevation angles between these four individual angles can be roughly interpolated.
127 individual radiators are fed through a waveguide with detour lines. At frequency F 1 , all detour lines are dimensioned in such a way that they emit at an elevation angle of 0 °. If the frequency is increased (F 2 ), the length of these detour lines no longer corresponds to the wavelength . The individual radiators are fed with different phase positions , radiator number 127 receives the phase later than radiator number 1, so the elevation angle is increased.
Although this type of beam swiveling is very simple, it is limited to a few permanently installed transmission frequencies and has the decisive disadvantage that no frequency changes are possible in the event of interference on these frequencies. Frequency modulation of the transmission pulse ( pulse compression method ) is only possible to a limited extent. In addition, the ST68U has a 2nd radiator group with which the entire antenna diagram can be swiveled upwards.
The radar device is equipped with a plot extractor with automatic target recognition, which can automatically process up to 128 target characters. Of these target signs, only 32 targets are then recognized as real targets and automatically reported and accompanied. The ST68U is the first radar device from Russian production to have a BITE system (SUSIK). This system should automatically detect and display errors in the radar device. In practice, however, 80% of all errors were caused by this system itself. Another special feature is the "Struggle" mode. The transmission energy is not distributed over four frequencies - and thus distributed at an angle of elevation - but is emitted in just one frequency and thus in an angle of elevation. Thus the energy density quadruples for this elevation angle.
This radar has also been used in NATO since the Republic of Hungary became a member .
| Technical data ST-68U "Tin Shield" | |
|---|---|
| Frequency range | E-band |
| Pulse repetition time | 0.7 and 1.3 ms |
| Pulse repetition frequency | 750 and 1500 Hz |
| Transmission time (PW) | 6 and 12 µs |
| Reception time | 800 µs |
| Dead time | |
| Pulse power | up to 2.5 MW |
| Average performance | 3.5 kW |
| displayed distance | 150 or 75 km |
| Distance resolution | 300 m |
| Opening angle | 0.45 ° |
| Hit count | 3 |
| Antenna round trip time | 6 s and 12 s |
Polest 68UM
The Polest 68UM mobile air defense and target assignment radar system also uses two ST-68UM (Russian designation: 36D6) and a 55G6-1 Nebo surveillance radar. and is transported on a MAZ-938B semi-trailer. The system also includes a MAZ-5224W power supply vehicle. The antenna 40V6M is transported with a third vehicle of the type KamAZ-4310 and with the hydraulically erecting mast, which is 23.8 m high, a range of up to 200 km is achieved. The system is capable of capturing, identifying and tracking cruise missiles and can also be used in conjunction with the S-300P long-range surface-to-air guided missile system. The Polest 68UM complex is protected by a fire unit with portable 9K310-Igla-1 or 9K38-Igla guided weapons.
