Decca Comparison frequency
Comparison frequency (in Decca) DECCA
The common frequency to which the incoming signals are converted in order that their phase relationships may be compared.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
A low-frequency hyperbolic radionavigation system based on phase comparison techniques
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM