LORAN
Overview
 
LORAN is a terrestrial radio navigation
Radio navigation
Radio navigation or radionavigation is the application of radio frequencies to determine a position on the Earth. Like radiolocation, it is a type of radiodetermination.The basic principles are measurements from/to electric beacons, especially...

 system using low frequency
Low frequency
Low frequency or low freq or LF refers to radio frequencies in the range of 30 kHz–300 kHz. In Europe, and parts of Northern Africa and of Asia, part of the LF spectrum is used for AM broadcasting as the longwave band. In the western hemisphere, its main use is for aircraft beacon,...

 radio transmitters in multiple deployment (multilateration
Multilateration
Multilateration is a navigation technique based on the measurement of the difference in distance to two or more stations at known locations that broadcast signals at known times. Unlike measurements of absolute distance or angle, measuring the difference in distance results in an infinite number of...

) to determine the location
Location (geography)
The terms location and place in geography are used to identify a point or an area on the Earth's surface or elsewhere. The term 'location' generally implies a higher degree of can certainty than "place" which often has an ambiguous boundary relying more on human/social attributes of place identity...

 and speed of the receiver.

The most recent version of LORAN in use is LORAN-C, which operates in the low frequency portion of the electromagnetic spectrum
Electromagnetic spectrum
The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object....

 from 90 to 110 Kilohertz. Many nations have used the system, including the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, and several European countries. Russia uses a nearly identical system in the same frequency range, called CHAYKA
CHAYKA
Chayka is a Russian terrestrial radio navigation system, similar to LORAN-C. It is also run on 100 kHz and is described like LORAN-C by its GRI.-Chayka-Chains:There are 5 Chayka-chains in use:...

.

LORAN use has been in steep decline, with the satellite based Global Positioning System
Global Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...

 (GPS) being the primary replacement.
 
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