The part of signals intelligence (SIGINT) based on intercepting signals from foreign instrumentation.
ODNI lists FISINT alongside COMINT and ELINT as components of SIGINT: signals intelligence is derived from intercepted signals, however they are transmitted, either individually or in combination. In the United States, SIGINT is collected, processed and reported by the NSA.1
ODNI classes FISINT as part of SIGINT, while it treats MASINT – the analysis of the physical attributes of objects and events – as a separate discipline. The International Spy Museum also lists the related category TECHINT: the analysis of equipment used by an adversary, for purposes including training and research.1,2
Sources
- Office of the Director of National Intelligence (USA), What is Intelligence?
- International Spy Museum (Washington, DC), Language of Espionage (glossary)
Checked: 4 November 2026