OVERVIEW:  The GIN SLING B radar is a trailer-mounted target acquisition and missile guidance radar for the HQ-2 aka HQ-2J SAM.  It operates in the NATO E/F- band (IEEE S-Band).

DETAILS:  The GIN SLING B illumination radar systems is associated with the HQ-2/SA-2 series SAM.  The GIN SLING B is an improved copy of the SNR-75/ FAN SONG B radar.  Like the FAN SONG, it employs a complex antenna arrangement which is employed to provide range and angle tracking of the intended target, as well as the transponder beacon in the SA-2 missile, which is flown to a collision with the target using a command uplink embedded in the SJ-202 radar.

The antenna system consists of a pair of antennas: Two of electromechanically scanning (aka "Lewis-scanner") antennas provided vertical and horizontal target search, usually conducted in conjunction with the battery's surveillance and height finding radars. This arrangement was made necessary because to the narrow, 10° × 2° surveillance beams of the GIN SLING radar could only be steered through a 10° arc.   These perpendicularly mounted antennas created a cross-shaped beam that was centered on the target to determine its height and azimuth. These beams perform a 'flapping' motion as they scan their sectors. The FAN SONG radar had a dead zone at low altitude, which, unless covered by AAA, allowed attacking aircraft a potential avenue of attack.  A third antenna mounted on the horizonal Lewis antenna may provide target tracking.

A UHF (0.3-1.0 GHz) parabolic antenna mounted on the right side of the array transmitted command signals to the missile, guiding it to the target, while the missile transponder beacon is tracked by the Lewis antennas. 

The GIN SLING B can track up to four targets simultaneously and engage a single target with up to three missiles.    The missile must pass through the guidance beam within seconds of launch to be acquired and steered to its target.
  

Specifications:

	Frequency:	2.965-2.990; 3.025-3.050 GHz (High E, Low F-band (NATO))
	PRF:		1100-1250; 2200-2500 pps (est)
	Power: 		 600 kW (peak)
	Range:		32,64 nm (instrumented); 
	Accuracy:		60, 180 m (est)
	Deploy/Stow time	60 minutes (approximate)
		
NOTES:  IOC 1967



SOURCES:    Jane's Radar and Electronic Warfare Systems, "Fan Song missile control radars," 02 July 2001;  Jane's Radar and Electronic Warfare Systems, "Gin Sling radar," 10 November 2000;https://www.radartutorial.eu/19.kartei/11.ancient/karte030.en.html ; Kopp, D. C. (n.d.). Engagement and fire control radars (S-band, X-band). Air Power Australia. http://www.ausairpower.net/APA-Engagement-Fire-Control.html, http://www.ausairpower.net/APA-PLA-IADS-Radars.html#mozTocId163075 and http://www.ausairpower.net/APA-SNR-75-Fan-Song.html; Steven J. Zaloga, "Red SAM: The SA-2 Guideline Anti Aircraft Missile" New Vanguard, pg. 41. ; Pike, John. "FAN SONG." GlobalSecurity.org. Last modified 7, 2019. https://www.globalsecurity.org/military/world/russia/fan-song.htm; NATO, "Current Soviet Electronic Equipment, Vol. C: Landbased, pg. I-C-13 (12 February 1969); SA-2 surface-to-Air missile. (n.d.). National Museum of the United States Air Force™. https://www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/196037/sa-2-surface-to-air-missile/; RSN-75 : USSR / Successional countries USSR (SOV). (n.d.). Armedconflicts.com. https://www.armedconflicts.com/RSN-75-t74858 ; IBP. (2007). Pakistan army weapon systems handbook volume 1 strategic information and weapon systems. Lulu.com, pg. 244.


