Navigation and Seamanship

6.3.4. LORAN -Working principle

LORAN is working based on the principle of the time difference between the receipt of radio signals from two radio transmitters positions at different places. The theory is to calculate the time between reception of the signals from the MASTER and SLAVE stations, which are emitted at different frequencies. The constant time difference between the radio signals from the two different stations can be represented by a hyperbolic line of position (LOP). The position of the receiver (vessel) can be determined by identifying the positions of the two synchronized stations. The vessel’s position is found as the intersection of the line of two LORAN stations.

Even though LORAN-C is the latest system, which was discontinued due to costlier in operation. U.S. Coast Guard terminated the transmission of all U.S. LORAN-C signals on February 8, 2010