Description

LORAN-C was a medium range hyperbolic radio navigation system, operated by the US Coast Guard, which allowed a receiver to determine its position by using multilateration principles to compare the difference in reception time of low frequency radio signals transmitted by a group of fixed, land-based radio beacons. In each group or "chain" of beacons, there was one "Master" and 2 to 5 "Secondary" or slave transmitters. In the main, the LORAN system was decommissioned in 2010 but some components of the system have been kept in service as a backup to the Global Positioning System (GPS).