radio display

Radio navigation or radionavigation is the application of radio waves to determine a position of an object on the Earth, either the vessel or an obstruction. Like radiolocation, it is a type of radiodetermination.
The basic principles are measurements from/to electric beacons, especially

Angular directions, e.g. by bearing, radio phases or interferometry,
Distances, e.g. ranging by measurement of time of flight between one transmitter and multiple receivers or vice versa,
Distance differences by measurement of times of arrival of signals from one transmitter to multiple receivers or vice versa
Partly also velocity, e.g. by means of radio Doppler shift.
Combinations of these measurement principles also are important—e.g., many radars measure range and azimuth of a target.

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