A type of electronic navigation system, used by aircraft and ships. The abbreviated name LORAN comes from LOng RAnge Navigation. LORAN is a low-frequency pulse navigation system based on latitude and longitude coordinates.

A master station transmits a pulse of energy that is received by the aircraft and by two or more slave stations. As soon as the slave stations receive the pulse, they transmit a pulse of their own, and these pulses are also received in the aircraft.

The computer in the LORAN receiver measures the difference in time the signals from the master station and from each slave station were received. For every time difference, there is a line, called a line of position (LOP), along which the aircraft is located. The computer determines the lines of position and displays the latitude and longitude of the aircraft. The pilot can enter the latitude and longitude of the destination airport or of waypoints along the way, and the LORAN will display the bearing to the location, the distance to that point, and the ground speed of the aircraft, and estimated time of arrival (ETA) at the point.

LORAN A. A LORAN system that operates with frequencies of 1,950 kHz, 1,850 kHz, and 1,900 kHz.

LORAN C. The LORAN system used in aircraft. It operates on a frequency of 100 kHz.