|Country of origin||Russia|
|Range||400 km for 20 m2 RCS(282 km for 5 m2)|
The Russian (former USSR) BRLS-8B "Zaslon" (Barrier) is an all-weather multimode airborne radar developed between 1975 and 1980 by the Tikhomirov Scientific Research Institute of Instrument Design as part of the weapons control system of the MiG-31 supersonic interceptor. The NATO reporting name for the radar is Flash Dance with the designations "SBI-16", "RP-31", "N007" and "S-800" also being associated with the radar.
The Zaslon is a Pulse-Doppler radar with a passive electronically scanned array (PESA) antenna and digital signal processing. The antenna used by the Zaslon is actually a multi-channel system comprising two separate electronically controlled arrays, an X band radar with 1700 emitters and a L band transponder with 64 emitters brought together into a single antenna. The antenna has a diameter of 1.1 meters and is fixed in position with a scanning sector of +/-70 degrees in azimuth and +70/-60 degrees in elevation. The X-band components of the radar uses reciprocal ferrite phase shifters that allow the radar to position beams in around 1.2 ms. This high performance is one of the big advantages of phased array radars compared with the previous generation of mechanically scanned arrays which take seconds to perform the same functions as a phased array. The detection performance of the Zaslon radar is stated to be 200 km against a target with a Radar cross section (RCS) of 16 m2, the radar can track up to 10 targets while engaging 4 of those at any one time with either R-33 radar guided or R-40, R-60 IR-guided air-to-air missiles. The Zaslon was the Soviet Union's first look-down/shoot-down radar. This made it much harder for United States Air Force aircraft and cruise missiles to penetrate the Soviet airspace at low altitude (through Terrain masking/clutter (radar)), without being detected.
The radar was a landmark in aviation since it was the first time a PESA radar (previously found only on ground-based systems and the B-1 strategic bomber) had been installed in a jet fighter. The Zaslon radar was publicly unveiled at the 1991 Paris Airshow with its associated MiG-31 interceptor, the Russians even removing the radome of the fighter to allow the Zaslon's revolutionary antenna to be seen. Also at Paris was the US F-117 Nighthawk (revolutionary for its use of stealth technology) which the Russians suggested should take to the air with the MiG-31 to see if the Zaslon could detect the F-117. Unfortunately no such contest was ever conducted though Russian experts were confident that Zaslon would have been able to detect the F-117 during flight.
Adopted in 1981 RP-31 N007 backstop (Russian -Zaslon).
The basic differences between other versions and the MiG-31BM:
The onboard radar complex of the MiG-31BM can track 24 airborne targets at one time, 6 of which can be simultaneously attacked by R-33S missiles.
The MiG-31M, MiG-31D, and MiG-31BM standard aircraft have an upgraded Zaslon-M radar, with larger antenna and greater detection range (said to be 400 km (250 mi) against AWACS-size targets) and the ability to attack multiple targets — air and ground — simultaneously. The Zaslon-M has a 1.4 m diameter (larger) antenna, with 50% to 100% better performance than Zaslon. In April 1994 it was used with an R-37 to hit a target at 300 km distance. It has a search range of 400 km for a 19/20 m2 RCS target and can track 24 targets at once, engaging six (282 km for 5 m2). Target speed increased from 5 Mach to 6 Mach, improving possibility of firing through the land. The MiG-31 is one of only a few aircraft able to intercept and destroy cruise missiles flying at extremely low heights.