OVERVIEW:  The OLS-27 IRST (Infrared Search and Track) is a passive airborne sensor that detects infrared radiation.

DETAILS: 
The OLS-27 onboard IR IRST expands the aircraft's combat capabilities for detection and tracking of air targets and allowing for stealthy/radar silent attacks.  It also increases the aircraft’s ability to make attacks in a heavy ECM jamming environment. The IRST also provides better angular resolution than radar due to the shorter wavelength.  However, attacks made with the IRST will be made at shorter ranges, because of atmospheric attenuation of the infrared waves.  The IRST is also affected by adverse weather conditions allowing it to be used only in visual meteorological conditions (VMC).   


Specifications:

	Frequency:	Infrared
	Range:		27 nm detection at high altitude vs. tail on attack, tgt at military 			power; 19nm tracking (approx)
			48-54 nm detection at high altitude vs. head on, tgt in afterburner; 				38nm tracking (approx)
			
NOTES:  
 

SOURCES: Mladenov, Alexander. Soviet Cold War Fighters. Fonthill Media, 2017, location 3497 (Kindle ed.) location 4819; "Infrared Search and Track." Wikipedia, the Free Encyclopedia. Last modified December 5, 2022. https://en.wikipedia.org/wiki/Infrared_search_and_track. ; Pike, John. "AIR FORCE SYSTEMS." GlobalSecurity.org. Accessed January 11, 2023. https://www.globalsecurity.org/military/library/report/2004/04fisher/7airforcesystems.htm.
