The determination of position, or the obtaining of information relating to position, by means of the propagation properties of radio waves.
Radiolocation. Radio determination used for purposes other than radionavigation.
Radionavigation. The use of radio signals to support navigation for the determination of position or direction, or for obstruction warning.
Source: Nick Ward, Vicechair, IALA e-Nav Committee, March 2009
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM