The Collaborative International Dictionary of English v.0.48:

Radiophare \Ra"di*o*phare\ (r[=a]"d[i^]*[-o]*f[^a]r), n. [Radio-
   + phare.]
   A radiotelegraphic station serving solely for determining the
   position of ships. The radius of operation of such stations
   was restricted by the International Radiotelegraphic
   Convention (1912) to 30 nautical miles.
   [Webster 1913 Suppl.]