Editing Infrared search and track (section)

== Performance ==
Detection range varies with external factors such as
* clouds
* altitude
* air temperature
* target's attitude
* target's speed

The higher the altitude, the less dense the atmosphere and the less infrared radiation it absorbs - especially at longer wavelengths. The effect of reduction in friction between air and aircraft does not compensate for the better transmission of infrared radiation. Therefore, infrared detection ranges are longer at high altitudes.

At high altitudes, temperatures range from −30 to −50&nbsp;°C - which provide better contrast between aircraft temperature and background temperature.

The Eurofighter Typhoon's PIRATE IRST can detect subsonic fighters from 50&nbsp;km from the front and 90&nbsp;km from the rear<ref>{{cite web |url= http://www.bmlv.gv.at/truppendienst/ausgaben/artikel.php?id=807 |access-date= 2014-02-05 |title= Der Eurofighter "Typhoon" (VII) - Radar und Selbstschutz |publisher= Österreicher Bundesheer |date= June 2008}}</ref> - the larger value being the consequence of directly observing the engine exhaust, with an even greater increase being possible if the target uses [[afterburners]].

The range at which a target can be identified with sufficient confidence to decide on weapon release is significantly inferior to the detection range - manufacturers have claimed it is about 65% of the detection range.