High Frequency Direction Finding System for strategic intelligence collection and emitter location. HF-DF, (popularly known as huff-duff) intercepts and locates voice and message traffic transmitted on short-wave channels. HF-DF systems operate at frequencies where the signals are reflected from the earth's ionosphere [skywave signals].
Similar to "Classic Bullseye" system in the US.
By kjfitz @ 2005-07-13 16:56:28