Omega (navigation system)

based on NASA Worldwind-globe [1] - location of Omega-transmitter A in Norway (distances)
Omega could determine position to a precision of ±2.2 km (1.4 mi). Later radio navigation systems were more accurate.

OMEGA was the first global-range radio navigation system, operated by the United States in cooperation with six partner nations. It was a hyperbolic navigation system, enabling ships and aircraft to determine their position by receiving very low frequency (VLF) radio signals in the range 10 to 14 kHz, transmitted by a global network of eight fixed terrestrial radio beacons, using a navigation receiver unit. It became operational around 1971 and was shut down in 1997 in favour of the Global Positioning System.