radio navigation

Radio navigation is a system that uses radio aids to guide aircraft or ships from one point to another. Early systems, like the "A-N" radio range, used low and medium frequencies. Aircraft with a simple radio receiver could follow a continuous tone indicating they were on course towards or away from a station.12

More advanced systems, such as Very High Frequency Omnidirectional Range (VOR), operate on different principles. VOR transmits two signals simultaneously in all directions, with a phase difference that varies with direction from the station. Aircraft receivers detect this phase difference to display a bearing. When combined with Distance-Measuring Equipment (DME), VOR provides a basic point-to-point guidance system. Radio navigation has been crucial in overcoming challenges posed by fog or darkness, and in enabling air and space travel.234