Defence Cluster's Passive Radar for Air Traffic Control is a class of radar that makes use of third-party illuminators. For example, public broadcasting services such as frequency modulation radio, to illuminate an aircraft(s) of interest and subsequently locate and track these aircrafts by processing the signals reflected from the aircraft.

Given the absence of a dedicated transmitter subsystem in passive radar systems, it serves as a cost-effective radar solution that requires no spectrum licensing, consumes significantly less power, requires minimal equipment and has reduced maintenance.