FISINT

FISINT (Foreign Instrumentation Signals INTelligence) is intelligence from the interception of foreign electromagnetic emissions associated with the testing and operational deployment of foreign aerospace, surface, and subsurface systems. Since it deals with signals that have communicational content, it is a subset of COMINT, which, in turn, is a subset of SIGINT. Unlike general COMINT signals, the content of FISINT signals is not in regular human language, but rather in machine to machine (instrumentation) language or in a combination of regular human language and instrumentation language. FISINT is also considered as a subset of MASINT (measurement and signature intelligence).