View source for JY-9 Radar

{{Infobox Radar
|name        = JY-9
|image       =
|caption     = JY-9
|country     = [[People's Republic of China]]
|introdate   = unknown
|number      = unknown
|type        = Fire Control
|frequency   = S band
|PRF         = 790 Hz
|pulsewidth  = 20 μs
|RPM         = 6, 12 rpm
|range       = 150 km (Pd=80%; Swerling I; 2 m<sup>2</sup>)
|altitude    = 10 km
|diameter    = 4.14 x 6.96 m
|azimuth     = 0-360°
|elevation   = 0-40°
|precision   = 120 - 140 m; azimuth 1.3°
|power       = 200 kW (peak)
|other names =
}}
The '''JY-9 Radar''' is a mobile [[S band]] low altitude search [[radar]] intended for use in air defense, gap filling, airport surveillance, and coastal defense. It is designed for effective detection of targets at low altitude in both [[Electronic countermeasures|ECM]] and natural [[clutter (radar)|clutter]] environments.  The general designer of the JY-9 is academician of [[Chinese Academy of Sciences]] Mr. Wu Manqing (吴曼青, born 1965), the head of 38th Research Institute, who is also the general designer of the [[JY-8 Radar]] and of the radar systems for the [[KJ-2000]] and [[KJ-200]] early warning aircraft.
==System construction==
The system consist of a radar/operations shelter, an [[Antenna (radio)|antenna]] pallet, and a power station shelter. It is transportable by air, rail, and sea.  The system can be setup or dismantled within 90 minutes, by a team of 8 men.
The JY-9 employs a dual-beam antenna assembly consisting of a deformed [[parabolic reflector]], two horns and two feed channels. One channel is used for transmit, but both are used for receive. The antenna rotates at 6 or 12 [[Revolutions per minute|rpm]] to provide all round coverage and can be mounted on a shelter or on the ground.
The JY-9 has high anti-[[Radar jamming and deception|jamming]] and anti-clutter capability due to the use of advanced techniques, including [[Pulse (signal processing)|pulse]] to pulse frequency agility, dual channel, JATS, wide operating band, low sidelobes, [[Moving Target Indication|MTD]] automatic spectrum processing, automatic clutter map and automatic residue map.  The [[MTBF|mean time between failures]] is better than 900 hours with Built-in test equipment (BITE).
The JY-9F three-dimensional low-altitude surveillance radar, is a new derivation of the JY-9 low-altitude radar. It is a fully coherent pulse-compression radar with a high reliability and mobility and can provide low-flying target information for national air defence information networks or for AAA or air traffic control systems. [http://www.janes.com/articles/Janes-C4I-Systems/JY-9F-low-altitude-surveillance-radar-China.html]
The JY-9F consists of an antenna assembly, an operations shelter, a trailer-installed shelter housing two diesel generators and an optional trailer-installed shelter. The antenna can be folded down or erected by a motor-driven mechanism and the assembling and disassembling of the system can be accomplished by a crew of eight men within one hour. This advanced radar incorporates the state-of-the-art techniques. The excellent low sidelobe antenna employed in the system has greatly enhanced the radar's anti-clutter capability and ECCM performance, giving improved low-altitude detection performance. Three AMTI processing channels are used, each equipped to handle a particular environmental condition, thereby providing maximum low-altitude target detection. The wideband and highly stable TWT+CFA transmitter guarantees a super-clutter visibility in excess of 40&nbsp;dB in the presence of ground clutter. The quadriphase Taylor code ensures a desirable consistency, high reliability and high stability. Meanwhile, the waveform agility can be realised. The JY-9F radar is characterised by high reliability and maintainability with an MTBF of more than 400 hours and MTTR of less than 30 minutes. Due to extensive BITE adopted in the system, troubleshooting probability reaches 95 per cent while 85 per cent of faults can be isolated to PCB level and all faults can be isolated to the replaceable unit level.
The system is manufactured by the East China Research Institute of Electronic Engineering(ECRIEE)/No.38 Research Institute.
==Specifications==
* S band
* Antenna: Dual beam with super cosecant² pattern
* RPM: 6, 12 rpm
* [[Beamwidth]]: 15°, 18° (vertical)
* [[Power (physics)|Power]] output: 200&nbsp;kW (peak)
* Pulsewidth: 20 μs
* [[Pulse repetition frequency|PRF]]: 790&nbsp;Hz
* Coverage: 360° ([[azimuth]]), 0 - 40° ([[elevation]])
* [[Altitude]]: 10&nbsp;km
* Range: 150&nbsp;km (Pd=80%; Swerling I; 2 m<sup>2</sup>)
* Detection accuracy: 80 m range; 0.3° azimuth
* [[Optical resolution|Resolution]]: 120 – 140 m; azimuth 1.3°
* Track capacity: 200 plots, 72 tracks
==References==
* [https://www.radartutorial.eu/19.kartei/11.ancient/karte081.en.html Radartutorial]
* [https://web.archive.org/web/20051217090350/http://jrew.janes.com/ Jane's Radar and Electronic Warfare]
[[Category:Ground radars]]
[[Category:Military radars of the People's Republic of China]]