Huff-Duff
From Biocrawler, the free encyclopedia.
High Frequency Direction Finder is usually known by its acronym HF/DF, pronounced Huff-Duff. This has become the common name for this type of equipment, and was coined during World War II.
Huff Duff is part of the armoury of the analysis of radio transmissions and is known as ELINT. It is the sister discipline to the analysis of messages SIGINT.
World War II
Along with ASDIC (sonar), Ultra code breaking (SIGINT) and radar, "Huff-Duff" was a valuable part of the Allies armoury in detecting German U-boats and commerce raiders during the Battle of the Atlantic.
The idea of using two or more radio receivers to find the bearings of a radio transmitter and with the use of simple triangulation find the approximate position of the transmitter had been known and used for years. The Royal Navy was the first to design an apparatus that could take bearings on the high frequency radio transmitters employed by the German Kriegsmarine in World War II.
Many shore based installations were constructed around the North Atlantic and when ever a U-boat transmitted a message "Huff-Duff" could get bearings on the approximate position of the boat. Because it worked on the electronic emission and not the content of the message it did not matter that the content was encrypted using an Enigma machine.
In 1942 the allies began to install Huff-Duff on convoy escort ships, enabling them to get much more accurate triangulation fixes on U-boats transmitting from over the horizon, beyond the range of radar. This allowed hunter-killer ships and aircraft to be dispatched at high speed in the direction of the U-boat, which could be illuminated by radar if still on the surface and ASDIC if it had dived.
References
- "Secret Weapon: U.S. High-Frequency Direction Finding in the Battle of the Atlantic" by Kathleen Broome Williams, Naval Inst Pr (October 1, 1996), ISBN 1557509352
Categories: World War II British electronics | World War II American electronics | World War II Allied electronics
