AN/MPQ-4

The AN/MPQ-4 was a mortar-locating radar mounted on two trailers: a power supply trailer and a transmitter/antenna trailer. It resembled the British Cymbeline radar, which played a similar role, in using a Foster dual-scanner feed that sent two beams at different elevations simultaneously and used the differences to calculate trajectory and point of origin.

The MPQ-4 could be operated by one soldier -- although preparation for movement and installation required at least four...