Decca Navigator System
（重定向自Decca navigation）
![](/Images/godic/202501/08/Accuracy_of_Navigation_Systems.svg4114.png")
![The display head, or](/Images/godic/202501/08/Decca_Navigator_Mk_124114.jpg")
![Decca Navigator Mk. 21, with the Decometer dials prominent.](/Images/godic/202501/08/Decca_Navigator_Mk_214114.jpg")
![An ap Decca receiver Mk II from the 1980s which could be purchased instead of leased. It could store 25 waypoints.](/Images/godic/202501/08/Decca_Receiver_Philips4114.jpg")
The Decca Navigator System was a hyperbolic radio navigation system which allowed ships and aircraft to determine their position by receiving radio signals from fixed navigational beacons. The system used low frequencies from 70 to 129 kHz. It was first deployed by the Royal Navy during World War II when the Allied forces needed a system which could be used to achieve accurate landings. After the war it was extensively developed around the UK and later used in many areas around the world.