LORAN: Long Range Navigation

LORAN is a radio navigation system developed by the United States for use on the Atlantic and Pacific Oceans during the Second World War.

LORAN consists of two kinds of radio stations called “master” and “slave.” The master station sends out signals which are received by the slave stations. Receivers on the slave stations measure the distance between master and slave. The master receiver measures signals from two different slave stations, which can be charted as a series of curved lines. These curved lines intersect to give two possible positions for the ship. One of these locations is then eliminated using another form of navigation and the remaining position is the ship’s exact location.