Definitions for "IRST"
Keywords:  infrared, passive, pilot, mig, typhoon
InfraRed Search and Track. A passive system that allows the pilot to track an aircraft by its heat signature from up to 50 nautical miles away.
Infrared Search and Track TE Thermo-Electric (cooler)
InfraRed Search and Track, e.g. as fitted to Su-27, MiG-29 and Typhoon - a passive system that allows the pilot to track an aircraft by its heat signature from up to 50nm away