How a Radio Navigation System Uses the Principle of Radio Communication

Radio navigation systems use communications sent from a beacon to a vehicle in order to plot a course to or from a radio beacon, or to use two or more beacons to triangulate the position of a vehicle to an almost exact location.

Morse

The earliest use of radio communications as a navigation aid for aircraft used simple Morse code to help a pilot maintain a course to or from a radio beacon. Two Morse letters were sent to an aircraft, A and N, which merged when the aircraft was moving directly towards the beacon. Each Morse letter was broadcast on one side of the aircraft. When the airplane moved off course, one letter would become dominant, thus alerting the pilot to the change of position.

Types

There are a variety of types of radio navigation systems that use communications sent from a radio tower. Following the use of Morse code radio, compasses were introduced that would point directly to the closest tower emitting signals. Automatic direction finders were also introduced that allowed pilots to calculate their exact location.

Charts

When using radio navigation, pilots use aeronautical charts to determine the radio station they should be tuned to in their approximate location. By finding the bandwidth of radio communications, pilots can determine which radio tower they are moving towards or away from.

References

• Thai Technics: Navigation Introduction
• Flight Simulator Navigation: ADF History