LORAN
Long Range Navigation. A System using a ground facility composed of a master station and a slave station. The airborne receiver computes the position of the aircraft by using two or more received master-slave pairs of signals. LORAN-A operates at 1850,1900 and 1950kHz. LORAN-C operates at 100 kHz. LORAN-A was replaced by LORAN-C in 1980.