LORAN, short for long range navigation, was a hyperbolic radio navigation system developed in the United States during World War II. It was similar to the UK's Gee system but operated at lower frequencies in order to provide an improved range up to 1,500 miles (2,400 km) with an accuracy of tens of miles. It was first used for ship convoys crossing the Atlantic Ocean, and then by long-range patrol aircraft, but found its main use on the ships and aircraft operating in the Pacific theater during World War II.
The AN/APN-4 was an airborne LORAN receiver used into the 1960s. It was built in two parts to match the UK's Gee system, and could be swapped with Gee in a few minutes.
AN/APN-4 LORAN in RCAF Canso (PBY) aircraft.
R-65/APN-9 in a B-17G aircraft
LORAN chart of the Yellow Sea, 1944
Radio navigation or radionavigation is the application of radio frequencies to determine a position of an object on the Earth, either the vessel or an obstruction. Like radiolocation, it is a type of radiodetermination.
Amelia Earhart's Lockheed Electra had a prominent RDF loop on the cockpit roof.
The Orfordness Beacon as it appears today.
VOR transmitter station
Cessna 182 with GPS-based "glass cockpit" avionics
