Stealth and counter-stealth on show at MAKS
Sep 2, 2013 Bill Sweetman | Aviation Week & Space Technology
While pursuing development of its own stealth fighter, Russia's defense industry is maturing counter-stealth radars. The Nizhny-Novgorod Research Institute (NNIIRT) brought the newest configuration of its multi-band 55Zh6ME radar complex, designed to support the Almaz-Antey S-400 Triumph surface-to-air missile system. It also used the show to unveil the new 55Zh6UME, a single-unit, dual-band system designed for customers with more modest needs and budgets.
The 55Zh6ME comprises three truck-mounted radar "modules," operating in metric (VHF), decametric (L) and centimetric (S) bands, all with active, electronically scanned array (AESA) radars. The VHF unit has an antenna area of 235 sq. meters (2,530 sq. ft.), carrying 168 VHF transmit-receive modules, and is claimed to be able to detect a target with a radar cross-section of 1 sq. meter at 510 km range and 30,000 meters altitude in jamming conditions. The radars can be deployed in 15 min., NNIIRT says.
The new 55Zh6UME has a smaller VHF array (with a 430-km range under the same conditions) with an L-band AESA trailer-mounted on the same structure, facing the opposite direction.
[NNIIRT's 55Zh6UME radar system combines two AESA radar antennas—VHF and L-band—operating back to back. The smaller antenna below the VHF array is an identification-friend-or-foe interrogator. (Credit: AW&ST /Bill Sweetman)]
NNIIRT's 55Zh6UME radar system combines two AESA radar antennas—VHF and L-band—operating back to back. The smaller antenna below the VHF array is an identification-friend-or-foe interrogator. (Credit: AW&ST /Bill Sweetman)
Stealth targets that claim radar cross section of less than 1 sq. meter do not achieve those numbers in the VHF band, according to NNIRT engineers. For instance, the Chinese Dongfeng-15 short-range ballistic missile has a 0.002-sq.-meter radar cross section in X-band, but is a 0.6-sq.-meter target in VHF, company officials tell Aviation Week. This is because radar waves are scattered by a "resonant" mechanism (rather than specular reflection, which stealth shaping is designed to manage) when the dimensions of the target, or its parts, are similar to the wavelength of the radar. They are not affected by shape or by surface coatings.
The S-400 and the 55Zh6ME are in service with the Russian armed forces, while the 55Zh6UME is now on offer for export.