Editing Infrared search and track (section)

{{Short description|Method for detecting and tracking objects which give off infrared radiation}}
{{Redirect|IRST|the time zone in Iran|Iran Standard Time}}
[[File:Regiment100thAnniversary2018-08.jpg|thumb|300px|An IRST sensor on a [[Sukhoi Su-35]]]]

An '''Infrared Search and Track''' ('''IRST''') system (sometimes known as '''infrared sighting and tracking''') is a method for detecting and tracking objects which give off [[infrared]] [[radiation]], such as the [[infrared signature]]s of [[jet aircraft]] and [[helicopter]]s.<ref name=Mahulikar>Mahulikar, pp. 218-245</ref>

IRST is a generalized case of [[Forward Looking Infrared]] (FLIR), i.e. from forward-looking to all-round [[situation awareness]]. Such systems are passive ([[thermographic camera]]), meaning they do not give out any radiation of their own, unlike [[radar]]. This gives them the advantage that they are difficult to detect.

However, because the atmosphere attenuates infrared to some extent (although not as much as [[visible light]]) and because adverse weather can attenuate it also (again, not as badly as visible systems), their range compared to a radar is limited. Within range, an IRST's [[angular resolution]] is better than radar due to the shorter [[wavelength]].