SJJ-9 Kouwayzar

Revision as of 22:44, 16 November 2016 by Riysa (talk | contribs) (→‎Guidance, Seeker & Electronics)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search
SJJ-9 Kouwayzar
File:Sjj-9.png
SJJ-9R1 under the wing of a TaH-29 Daqanoush.
TypeAir-to-air missile
Place of origin Riysa
Service history
In service2006-present
Used by Riysa
Production history
DesignerIBS Design Bureau
ManufacturerRiysian High Command
Unit cost$ 1,400,000 (quoted export price, 2015)
Produced2006-present
Specifications
Weight225 kg
Length3.7 m
Diameter200 mm
Warhead20 kg Continuous-rod
Detonation
mechanism
Contact, proximity

EngineThrottable ducted rocket
Operational
range
180 km
SpeedMach 4.5
Guidance
system
Inertial mid-course with datalinked updates, active radar homing (R1), semi-active radar homing (R2), dual-band infrared (H), passive radar homing/anti-radiation (MR)
Launch
platform
Aircraft

The SJJ-9 Kouwayzar (Arabic: الكويزر, English: Quasar) is one of the newest families of beyond-visual range air-to-air missiles for the Riysian Air Force, and will become the primary beyond-visual range missile of the RiyAF, eventually replacing the older SJJ-7 Shihab. The missile is designed primarily to counter opposing supermaneuverable fighters, but can also be effectively used against other air targets in both clear and adverse weather conditions, including cruise missiles. After over 10 years of development, the missile started full-rate production in early 2006, and entered Riysian service in mid 2006. Since its introduction, over 7,000 missiles spanning four variants have been produced for use by the Riysian Air Force.

History

Description

Airframe and Warhead

The missile's airframe is known to be mostly constructed of chromium-alloyed "inox" steel. As heat buildup from electronics and air friction is a major issue in missile design, especially with the high speeds expected to be encountered in a ramjet design, much of its capabilities depend on effective heat management solutions. It was determined by the design team that inox steel was the most cost-effective material for retaining structural integrity, allowing the desired characteristics of the missile to be implemented without having to resort to costly exotics.

All versions use a 20 kilogram continuous rod warhead, activated by either a laser proximity or a contact fuse. Steel rods are used, as is typical in most warheads of the type. The Riysian Air Force is known to prefer continuous rod warheads over blast/fragmentation warheads, despite their smaller effective radius.

File:Tah29sjj9.png
A TaH-29T firing a SJJ-9 at a target drone.

Propulsion and Control

The SJJ-9 uses a throttleable ducted rocket with an integral solid booster, allowing the missile to achieve higher average speeds than conventional solid-fuel rocket motors, and with significantly increased kinematic range. Compared to some forms of solid rockets, the motor is stated as being relatively simple and easy to maintain, highly flexible, long-ranged, and easily controllable. The missile can reputedly travel up to 180 kilometers under its own power, but is affected by the launch aircraft's kinematics as well as those of the target. Reflecting advances in propellant chemistry, the smokeless propellant and booster are aluminium-free, to prevent them from being detected at long range by infrared detectors.

Aerodynamic control of the missile is provided by both traditional electrically-actuated cruciform tail surfaces, and through gas-dynamic control of thrust via four nozzles located at the rear end of the missile. Gas-dynamic control, also known as thrust vectoring, allows for greater maneuverability when used in conjunction with traditional control surfaces, by redirecting some or all of the thrust output of the engine, causing the missile to turn quicker than could be achieved by control surfaces alone. In the case of the SJJ-9, the engine nozzle is gimbaled, allowing for motion in three axes. Between the inox steel airframe and the manueverability inherent in the missile design, the SJJ-9 can pull up to 45 Gs when maneuvering against a target, and the missile's software allows for limited adjustment of the terminal speed to help better match its target.

Guidance, Seeker & Electronics

File:Jtkm-30r.png
The JTKM-30R seeker used in the SJJ-9R1.

The SJJ-9 family can be considered to be the first truly digital air-to-air missile fielded by the Riysian Air Force. Making use of advances in computing technology, all of the electronic sub-systems, such as the seeker head processor and control surface actuators, are under the central control of a 50 MHz microprocessor. Processed digital data from each sub-system is fed into the software-based central missile processor, which then feeds back a response. This allows it to control all flight, datalink, and targeting functions, as well as conduct self-diagnostics and adaptive fusing. The processing power and memory of the general microprocessor allows for the implementation of complex algorithms, improving seeker discrimination and countermeasure resistance, with roughly 88,000 lines of code written. As reserve power and memory is available for growth opportunities, the missile can thus be updated continually in its software with improved algorithms and more streamlined code, improving its performance without having to make modifications to the hardware. Optimization of the missile's software before a sortie for improved performance against expected targets, originally pioneered with the SMS-700 Zawba'a anti-ship missile, can also be performed at any location with the proper equipment and technical staff.

As is common among Riysian missiles, and now greatly simplified by the introduction of the digital systems architecture, the Kouwayzar family consists of a common airframe and missile package combined with different seeker heads per variant. All missiles types in addition contain a three-axis inertial reference unit for midflight inertial navigation, relying on more efficient fiber optic gyros and accelerometers instead of more traditional mechanical units.

The SJJ-9R1 variant uses an JTKM RS-301R digital active radar seeker, operating in the X-band. The seeker is a planar array type with a solid state transmitter, capable of detecting a 5m2 target out to 35 kilometers, and scans as a two-plane monopulse system, measuring spectral reflection from multiple angles for improved ECCM. To save on internal volume, and eliminate signal transmission losses and latency, its radiofrequency processor is fitted directly into the array using thin-film hybrid microwave circuits; the output from the RF processor is then heterodyned down into an intermediate frequency signal, which is then converted directly to a digital signal and routed into the missile body, replacing complex microwave tubing with simpler wiring. Additional rate-sensing gyros are fitted behind the array to provide a reference for the missile processor. Reportedly, the RS-301R unit has a narrowband home-on-jam capability, which allows for targeting of the source if the processor detects interference in the seeker. It also has a low probability of intercept mode, based around dynamic modulation of the radar power output and a frequency-modulated continuous wave waveform. As the missile approaches the target, after having detected it with its seeker, the processor measures and accordingly scales back emitting power, reducing the likelihood of the missile's emissions being detected. The FMCW waveform reduces its chance even further, by continuously radiating at low power and adjusting it over a range of frequencies, causing it to get lost in background noise.

The SJJ-9R2 uses a semi-active seeker of an unknown type. This variant has gotten little attention, and some analysts are of the opinion that it is not actively being produced.

The SJJ-9H is an all-aspect infrared-homing variant, using a ITS ZHCT-15B Hilal-B infrared seeker, which is an upsized version of the seeker used in the SJJ-10 Muthnib. To keep cooling requirements low and to save money during development, the characteristics of its predecessor were kept, rather than scaled up. The seeker is a mercury-cadmium-telluride two-color infrared detector, operating on two different wavelengths for improved countermeasure resistance, with a zinc selenium (ZeSe) seeker window for filtering out wideband interference. The seeker scanning technique used is rosette scanning, also known as a psuedoimager as it produces a two-dimensional false image of the target, utilizing the extra processing power offered by the SJJ-9's control system system to provide a mechanically simpler seeker, yet with a high field of view. The scanner works by having fixed infrared detectors but with rotating mirrors, allowing for multiple angles of a target to be viewed at once, improving countermeasure resistance. The seeker is capable of independent target prosecution; using the high performance processor core, contrast images detected by the scanner is saved and analyzed, with the computer then deciding whether to engage that target or not. The detector assembly itself is in turn flexible with a gimballed mount, allowing for a field of view of 150 degrees off-boresight (+/- 75 degrees). Against a typical fighter traveling at subsonic speeds, detection range is estimated to be about 15 kilometers from the frontal aspect and 27 kilometers from the rear aspect; for a supersonic or afterburning target, this can be as much as 23 kilometers and 42 kilometers, respectively.

The SJJ-9MR is an anti-radiation-homing variant, using a JTKM SMR-8 wideband digital radiation seeker. The seeker consists of a gimbaled interferometric array with five distinct hemispherical receiving antennas, allowing for reduced target location error and compensation for missile pitch and yaw. The system operates exclusively in the 8-12 GHz - X band, NATO I/J bands - range, the same as most airborne radar systems. The seeker's digital architecture and the missile's high processing power gives it high gain compared to analogue receivers, and allows for the use of complex processing algorithms, making it potentially effective even against low probability of intercept (LPI) radars. Further measures have also been taken to improve this capability, like integration of the analogue-to-digital converter into the receiving antenna itself to reduce losses. Depending on the plane in question, the missile seeker can be integrated with the carrier's own RWR/ESM system, allowing it to receive targeting information and to use algorithms such as match filtering, to better target the radar system in question. Seeker range is unknown but thought to be up to 200 kilometers, depending on the system being detected.

All versions of the missile utilize a low-powered directional datalink, operating in UHF frequencies. This datalink can operate in is two-way when used with Riysian aircraft from the TaH-29 Daqanoush B-3 model onwards. The missile can transmit kinetic and targeting data back to the launch aircraft, aiding in its effectiveness. Non-Riysian aircraft or older Riysian aircraft, that are datalink-enabled, must rely on a one-way link unless appropriately modified.

The missile may be fired in two modes:

  • "Linked mode": The standard firing mode, where the launching aircraft uses the datalink to continuously update the missile until the seeker acquires a target.
  • "Fire-and-forget mode": Allows the missile to be fired as a fire-and-forget missile without utilizing the datalink, allowing the launching aircraft to turn away and evade instead of exposing itself to enemy fire. The missile acquires a target before launch with its seeker at short range, or uses its inertial reference system to fly to a predetermined search box for a long range attack.

Variants

  • SJJ-9R1: Variant with an active radar homing seeker.
  • SJJ-9R2: Variant with a semi-active radar homing seeker. Not in service
  • SJJ-9H: Variant with an infrared-homing seeker.
  • SJJ-9MR: Variant with an anti-radiation seeker.

Service History

Operators

 Riysa  Aquitayne Template:Country data Republic of Vietnam Template:Navbox Riysian Missiles