Decca navigator system
A distributed arrangement of fixed, phase locked, continuous wave transmitters operating on harmonically related frequencies and special receiving and display equipment carried on a mobile craft whereby the latter can determine its position.
The system depends for its operation on phase comparison of the signals from the transmitters brought to a common comparison frequency within the receiver.
The master station also initiates timed switching of transmissions when required for the purpose of lane resolution.
The operating frequencies are in the region of 100 kHz.
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