Toran
4-4-340
A precise system of hyperbolic position fixing in which a mobile station can obtain its position by the determination of the phase differences between the high frequency waves emitted by a pair of confocal transmitters and the transmission from a fixed reference transmitter.
Position fixing is effected by comparing the low frequency beat notes produced by the two confocal transmitters and the modulation note on the fixed transmitter.
The modulation of the fixed transmitter is produced by a fixed compensating receiver, which receives the transmissions from the confocal transmitters and uses the resultant beat note (which includes any instability of frequency and phase of the confocal transmitters) as a means of modulating the fixed transmitter which transmits the phase reference to the mobile receiver.
The operating frequency is in the region of 2 MHz and the maximum range is 300 miles.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
