Editing Signals intelligence (section)

===Complementary relationship to COMINT===
Combining other sources of information and ELINT allows traffic analysis to be performed on electronic emissions which contain human encoded messages. The method of analysis differs from SIGINT in that any human encoded message which is in the electronic transmission is not analyzed during ELINT. What is of interest is the type of electronic transmission and its location. For example, during the [[Battle of the Atlantic]] in [[World War II]], [[Ultra (cryptography)|Ultra]] COMINT was not always available because [[Bletchley Park]] was not always able to read the [[U-boat]] [[Enigma machine|Enigma]] traffic. But [[high-frequency direction finding]] ("huff-duff") was still able to detect U-boats by analysis of radio transmissions and the positions through triangulation from the direction located by two or more huff-duff systems. The [[Admiralty (United Kingdom)|Admiralty]] was able to use this information to plot courses which took convoys away from high concentrations of U-boats.

Other ELINT disciplines include intercepting and analyzing enemy weapons control signals, or the [[identification, friend or foe]] responses from transponders in aircraft used to distinguish enemy craft from friendly ones.