Human intelligence (HUMINT) is intelligence-gathering by means of human sources and interpersonal communication. It is distinct from more technical intelligence-gathering disciplines, such as signals intelligence (SIGINT), imagery intelligence (IMINT) and measurement and signature intelligence (MASINT). HUMINT can be conducted in a variety of ways, including via espionage, reconnaissance, interrogation, and witness interviews. Although associated with military and intelligence agencies, HUMINT can also apply in various civilian sectors such as law enforcement.
Signals intelligence (SIGINT) is the act and field of intelligence-gathering by interception of signals, whether communications between people (communications intelligence (COMINT)) or from electronic signals not directly used in communication (electronic intelligence (ELINT)). As classified and sensitive information is usually encrypted, signals intelligence may necessarily involve cryptanalysis (to decipher the messages). Traffic analysis—the study of who is signaling to whom and in what quantity—is also used to integrate information, and it may complement cryptanalysis.
COMINT (communications intelligence) is a sub-category of signals intelligence that engages in dealing with messages or voice information derived from the interception of foreign communications. COMINT is commonly referred to as SIGINT, which can cause confusion when talking about the broader intelligence disciplines. The US Joint Chiefs of Staff defines it as “Technical information and intelligence derived from foreign communications by other than the intended recipients”.
Electronic signals intelligence (ELINT) refers to intelligence-gathering by use of electronic sensors. Its primary focus lies on non-communications signals intelligence. The Joint Chiefs of Staff define it as “Technical and geolocation intelligence derived from foreign noncommunications electromagnetic radiations emanating from sources other than nuclear detonations or radioactive sources.” Signal identification is performed by analyzing the collected parameters of a specific signal, and either matching it to known criteria, or recording it as a possible new emitter. ELINT data are usually highly classified, and are protected as such.
Imagery intelligence (IMINT) is an intelligence gathering discipline wherein imagery is analyzed (or “exploited”) to identify information of intelligence value. Imagery used for defense intelligence purposes is generally collected via satellite imagery or aerial photography. As an intelligence gathering discipline, IMINT production depends heavily upon a robust intelligence collection management system. IMINT is complemented by non-imaging MASINT electro-optical and radar sensors.
Measurement and signature intelligence (MASINT) is a technical branch of intelligence gathering, which serves to detect, track, identify or describe the distinctive characteristics (signatures) of fixed or dynamic target sources. This often includes radar intelligence, acoustic intelligence, nuclear intelligence, and chemical and biological intelligence. MASINT is defined as scientific and technical intelligence derived from the analysis of data obtained from sensing instruments for the purpose of identifying any distinctive features associated with the source, emitter or sender, to facilitate the latter’s measurement and identification.
Human intelligence
Wikipedia
https://en.wikipedia.org/wiki/Human_intelligence
Human intelligence (HUMINT) is intelligence-gathering by means of human sources and interpersonal communication. It is distinct from more technical intelligence-gathering disciplines, such as signals intelligence (SIGINT), imagery intelligence (IMINT) and measurement and signature intelligence (MASINT). HUMINT can be conducted in a variety of ways, including via espionage, reconnaissance, interrogation, and witness interviews. Although associated with military and intelligence agencies, HUMINT can also apply in various civilian sectors such as law enforcement.
Signals intelligence
Wikipedia
https://en.wikipedia.org/wiki/Signals_intelligence
Signals intelligence (SIGINT) is the act and field of intelligence-gathering by interception of signals, whether communications between people (communications intelligence (COMINT)) or from electronic signals not directly used in communication (electronic intelligence (ELINT)). As classified and sensitive information is usually encrypted, signals intelligence may necessarily involve cryptanalysis (to decipher the messages). Traffic analysis—the study of who is signaling to whom and in what quantity—is also used to integrate information, and it may complement cryptanalysis.
**
Communications intelligence
https://en.wikipedia.org/wiki/Signals_intelligence#Communications_intelligence
COMINT (communications intelligence) is a sub-category of signals intelligence that engages in dealing with messages or voice information derived from the interception of foreign communications. COMINT is commonly referred to as SIGINT, which can cause confusion when talking about the broader intelligence disciplines. The US Joint Chiefs of Staff defines it as “Technical information and intelligence derived from foreign communications by other than the intended recipients”.
**
Electronic signals intelligence
https://en.wikipedia.org/wiki/Signals_intelligence#Electronic_signals_intelligence
Electronic signals intelligence (ELINT) refers to intelligence-gathering by use of electronic sensors. Its primary focus lies on non-communications signals intelligence. The Joint Chiefs of Staff define it as “Technical and geolocation intelligence derived from foreign noncommunications electromagnetic radiations emanating from sources other than nuclear detonations or radioactive sources.” Signal identification is performed by analyzing the collected parameters of a specific signal, and either matching it to known criteria, or recording it as a possible new emitter. ELINT data are usually highly classified, and are protected as such.
Imagery intelligence
Wikipedia
https://en.wikipedia.org/wiki/Imagery_intelligence
Imagery intelligence (IMINT) is an intelligence gathering discipline wherein imagery is analyzed (or “exploited”) to identify information of intelligence value. Imagery used for defense intelligence purposes is generally collected via satellite imagery or aerial photography. As an intelligence gathering discipline, IMINT production depends heavily upon a robust intelligence collection management system. IMINT is complemented by non-imaging MASINT electro-optical and radar sensors.
Measurement and signature intelligence
Wikipedia
https://en.wikipedia.org/wiki/Measurement_and_signature_intelligence
Measurement and signature intelligence (MASINT) is a technical branch of intelligence gathering, which serves to detect, track, identify or describe the distinctive characteristics (signatures) of fixed or dynamic target sources. This often includes radar intelligence, acoustic intelligence, nuclear intelligence, and chemical and biological intelligence. MASINT is defined as scientific and technical intelligence derived from the analysis of data obtained from sensing instruments for the purpose of identifying any distinctive features associated with the source, emitter or sender, to facilitate the latter’s measurement and identification.