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DGNSS of Korea, South Korea's industrial positioning Leading to the Ministry of Maritime Affairs and Fisheries Satellite Navigation Central Office

Loran-C is a long range radio navigation system that can estimate location with high accuracy and has a wide scope of application such as sea, land and air navigation. The name originates from LOng RAnge Navigation. Loran is distinguished from other systems by its main principle of emitting pulse waves, and the different name designations such as Loran-A, Loran-B, Loran-C and Loran-D demonstrate that they are different from the first version of Loran.

In 1940, a long range precision air navigation system that could estimate locations with an accuracy of 200nm to 200m was first proposed by Professor J.A. Pierce and his team from Harvard University. The initial system was developed as 2MHz Loran-A for operation and later as a low-frequency Loran system called LF Loran. The first fully automatic LORAN system was CYCLAN (later called CYTAC) using 180kHz.

In the Loran-C system, one master station and three or more secondary stations (usually four) comprise a chain. At present, there are 27 Loran-C chains (68 transmitting stations) in operation worldwide including the Korean Loran-C Chain.

The range of use is about 1,200 miles (2,200km) and users with appropriate receivers can use the system in all weather conditions within this range. Because it uses a stable frequency of 100kHz and due to its long-range radio wave characteristics, it is considered a superior radio navigation system compared to the original radio navigation devices.

These days, most advanced countries are preparing to switch to the e-Loran system, which supplements the drawbacks of the existing Loran-C. The e-Loran is expected to be utilized in various fields for time, timing and navigation information.

Types of Loran

Types of Loran
Method Estimation method Frequency Range of use Degree Development year
Loran-A Time difference 2㎒ 600 0.5-5NM 1942
Loran-B Time difference, Phase difference 2㎒ 25 15-100m Post-testing disposal
Loran-C 100㎒ 1,200 500m 1959
Loran-D 100㎒ 500 20-360m For U.S. Navy