n. 双曲线远程导航系统

Loran \Lor"an\ (l[^o]r"[a^]n or l[=o]r"[a^]n), n. [Acronym, from
LOng RAnge Navigation] (Naut., aviation)
A system of electronic navigation in which a vessel or
aircraft determines its latitude and longitude by measuring
the time differences between low frequency radio
transmissions from two stationary transmitters (slaves) and a
stationary master transmitter. Contrary to the name, Loran is
a medium range system, usually effective for no more than a
few hundred miles from shore. The first commercial system was
called Loran A; the latest (and final) development is Loran
C. [acronym]
[RDH]