Type 978

The British Type 978 shipboard radar is an older navigation radar fitted in the few surviving ROTHESAY-class frigates and the FEARLESS -class amphibious ships of the Royal Navy. It survives in numerous ships of other navies.

The antenna is a "double cheese," resembling a hollowed-out half-wheel of cheese. Pulses are emitted from the upper half and received in the lower half of the reflector opening. The Type 978 was based on the commercial Decca 45, one of several Decca...