OVERVIEW: Infrared Search and Track (IRST) 2nd Gen systems are passive infrared sensors with imaging capabilities that enhance target detection, tracking, and identification without active emissions.

GENERAL DESCRIPTION: Second-generation IRST systems employ imaging infrared detectors, often utilizing focal plane arrays, to provide detailed thermal images of targets in mid-wave and long-wave IR bands. This allows improved target recognition and engagement in all weather and low-visibility conditions. Widely adopted from the 1980s onward, these systems are integrated on fighter aircraft and naval platforms to complement radar by offering stealthy detection of airborne and maritime threats.

ROLE SUMMARY:
Category: Passive Infrared Imaging Target Detection
Primary Use: Long-range detection, tracking, and identification of aerial and surface targets
Function: Thermal imaging and passive scanning for situational awareness and fire control cueing
Platform: Fighter aircraft, maritime patrol aircraft, naval vessels
Integration: Works with radar, weapons systems, and electronic warfare suites

See Specific information under [Sensors/EW] and [Properties] sections.

SOURCE:
Jane’s Airborne Sensors
https://en.wikipedia.org/wiki/Infrared_search_and_track