Type M Raydist

4-4-275

A hyperbolic co-ordinate Raydist system which uses a single reference transmitter ashore, a transmitter on the vessel, whose frequency is offset by a few hundred cycles from that of the reference transmitter, and nominally three receivers, suitably spaced from each other, ashore.

The audio heterodyne frequency produced is transmitted via cable or radio link from each receiver to a common location, where it is phase compared.

The position information derived from the two hyperbolae is transmitted to the vessel by radio link.

The system is limited to one vessel for each pair of radio frequencies employed.

Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)

English