Decca

radio-beam system

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June 25, 2026

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The Decca system is a radio navigation technology that helps determine a craft's position. Introduced in 1946 by the British company Decca, it is a hyperbolic system that uses phase differences between continuous-wave signals from synchronized ground transmitters.12

Unlike systems that rely on the time difference of pulse arrivals, Decca uses the phase difference of signals to establish hyperbolic position lines. This method provides accurate and reliable positioning within a range of 100–300 miles from the primary station. The Decca system is particularly favored by fishermen for its precision in returning to specific fishing grounds.1

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commercial fishing
Fish finding
…satellite-transmitted position-fixing equipment such as Decca Navigator, Loran, and Satnav. These enable a skipper to return to the precise position where fish are spotted or to a particular location such as a coral reef or where gear has been set. Microprocessor technology allows information from various instruments such as sonar,…
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…satellite-transmitted position-fixing equipment such as Decca Navigator, Loran, and Satnav. These enable a skipper to return to the precise position where fish are spotted or to a particular location such as a coral reef or where gear has been set. Microprocessor technology allows information from various instruments such as sonar,…
Read More

navigation
Position hyperbolas
Decca, named for the British company that introduced it in 1946, is a hyperbolic system related to loran. Its primary and secondary transmitters broadcast different harmonics of a common frequency as continuous waves, rather than pulses. The hyperbolic position lines for any pair of transmitters…
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Decca, named for the British company that introduced it in 1946, is a hyperbolic system related to loran. Its primary and secondary transmitters broadcast different harmonics of a common frequency as continuous waves, rather than pulses. The hyperbolic position lines for any pair of transmitters…
Read More