As defined by FS-1037C and ITU Radio Regulations, radiodetermination is:[1]
the determination of the position, velocity or other characteristics of an object, or the obtaining of information relating to these parameters, by means of the propagation properties of radio waves
There are two main fields to radiodetermination:[1]
Radar is a radiodetermination system based on the reflection (or retransmission) of a radio wave by an object at a position to be determined.[1]