Developed recently by Agat/KB Radar in Byelorussia, the Vostok is an intended replacement for the P-18 Spoon Rest series. It is a digital solid state design, operating in the VHF band. While detailed specifications have been disclosed, design details have not, especially in relation to the internal architecture of the design.
The manufacturer claims a detection range of ~40 nautical miles against the F-117A Nighthawk, or other types with similar VHF band RCS, in a jammed environment, and 190 nautical miles in an unjammed environment, with an overall 30 to 40% improvement in range performance against the Spoon Rest D/E. Two demonstrators were built and displayed at the Milex 2007 industry expo in Minsk.
A technical white paper and concurrent discussion paper reveal some interesting details, although not as much as has been disclosed on competing Russian designs like the Nebo SVU.
The design uses a unique wideband "Kharchenko" square ring element radiator, arranged in a diamond lattice pattern, intended to improve frequency agility against earlier VHF designs. The boxes distributed through the framework of the active array antenna are transmit-receive modules for the radiating elements. The cited system MTBF is 1200 hours, exceptional for this class of radar. The hydraulically folded and elevated antenna is mechanically rated for 65 knot wind gusts, and both levelling of the platform and antenna deploy/stow operations are fully automated.
Specific design aims in the Vostok E included overcoming common limitations in legacy VHF radars, in particular the poor sensitivity and clutter rejection performance, the high peak power which exposes the radar to ESM equipment, the long time to deploy and stow the antenna, and the poor fractional bandwidth which limited frequency agility.
The radar has a centre frequency of 175 MHz, and is frequency agile across fifty discrete frequency channels in the radar passband, using either random frequency hopping, or an adaptive control law which avoids frequency channels occupied by jammers.
Three channels are used for adaptive suppression of jammer signals. Low peak power is used to minimise detection range against hostile ESM. Coherent integration techniques are used, and all signal processing is digital. An adaptive processing technique is used for clutter rejection (whether this qualifies as STAP will depend on future disclosures). The Digital MTI processing is claimed to provide a dynamic range of 50 to 60 dB.
The cited RMS ranging error is 25 metres, angle error 1.1°, and velocity error 1.8 m/s, bearing to a jammer can be measured with an error of ±1°. This performance is not as good as the AESA design in the Nebo SVU, and the Vostok E lacks a heightfinding capability.
The fully automated digital data processing subsystem provides a range of automatic tracking modes, and is designed to interface to cable or RF datalink channels to other IADS elements. No less than 120 aerial targets can be tracked. A satellite navigation terminal is integrated to facilitate rapid operation starts, in a "shoot and scoot" environment. A digital map system is provided to facilitate operations, the design can display target parameters, and programmable engagement zones or other airspace boundaries. The radar is also equipped with a signal emulator which generates synthetic target tracks, and possibly jamming waveforms. Signal and data processing is performed in the radar van equipment.
The time to deploy or stow the antenna is cited at less than 6 minutes, making this a genuine "shoot and scoot" design. The operator van is based on the same arrangement as the van for the truck mounted Ranzhir E variant or Polyana command posts, carried on a 6 x 6 MZKT 65273-020 series chassis.
A production Vostok E will be a formidable 2D acquisition radar, by virtue of its modern RF design and high mobility. As a replacement for the legacy Spoon Rest, the Vostok is much more capable and mobile than the 1L13 Nebo SV / Box Spring used by Russian forces. We should not be surprised if a future Vostok AESA derivative emerges, as a competitor to the larger Nebo SVU. KBR reported the first export sale, to an undisclosed customer, early in 2009.
