Alternative term: Phantom target (U.S.A.)
A resonant cavity, with small damping, energised by part of the transmitted pulse power. The train of damped oscillations, immediately following the transmitted pulse, is fed into the radar receiver to provide an overall test of the radar set.
Reference: B.S. (modified)
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
Centre of buoyancy
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM