A radio direction finder (RDF) is a device for finding the direction to a radio source. Due to low frequency propagation characteristic to travel very long distances and "over the horizon", it makes a particularly good navigation system for ships, small boats, and aircraft that might be some distance from their destination (see Radio navigation). The distinct technology Range and Direction Finding was the abbreviation used to describe the predecessor to radar.
Read more about Radio Direction Finder: History, Operation, Usage in Maritime and Aircraft Navigation, Automatic Direction Finder (ADF)
Famous quotes containing the words radio and/or direction:
“The radio ... goes on early in the morning and is listened to at all hours of the day, until nine, ten and often eleven o’clock in the evening. This is certainly a sign that the grown-ups have infinite patience, but it also means that the power of absorption of their brains is pretty limited, with exceptions, of course—I don’t want to hurt anyone’s feelings. One or two news bulletins would be ample per day! But the old geese, well—I’ve said my piece!”
—Anne Frank (1929–1945)
“Your Englishman, confronted by something abnormal will always pretend that it isn’t there. If he can’t pretend that, he will look through the object, or round it, or above it or below it, or in any direction except into it. If, however, you force him to look into it, he will at once pretend that he sees the object not for what it is but for something that he would like it to be.”
—James Agate (1877–1947)