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An introduction to the main Intelligence Collection Disciplines

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1. Defining Intelligence

The word intelligence comes from the Latin “intus” (inside) + “lego” (to read, understand, and gather ideas and information about someone or something) and denotes the practice of researching, collecting, and processing information on threats and dangers to national security, to support the protection of a country’s interests, properties and people. In other cases, it may be used to investigate diplomatic negotiations, economic programs, or private corporations.

The intelligence activity is very ancient. In fact, the Chinese strategist Sūnzǐ (Sun Tzu) already in the 5th century BCE theorized the use of spies in his military treatise “Sūnzǐ Bīngfǎ”, The Art of War. It is the result of the intelligence cycle, a process through which intelligence is obtained from several different sources, through the gathering, evaluation, analysis, integration, and interpretation of information, and is then made available to intelligence customers, to drive their decisions. By using a multiplicity of sources, the chance of erroneous conclusions can be reduced, and the information available may enable the implementation of ad hoc and well-developed strategies.

Depending on the operational needs and the potential impact they may have, information is disseminated immediately or not. Often, even if immediate, they risk being based on fragmented data and may contain inaccuracies that will later have to be corrected. Conversely, when the analyst has enough time to compare, analyze and evaluate the information collected, the conclusions will be much more accurate and reliable.

Intelligence is divided into three levels that have a hierarchical nature; however, in order to have a comprehensive analysis, all levels are needed as they influence each other:

  • Strategic intelligence that is forward-thinking, and it consents policymakers to make decisions of long-term importance.

  • Operational intelligence that is linked to real-time events in a specific area, thus real-time information needs to be produced to determine the current and upcoming capability on an ongoing basis.

  • Tactical intelligence, which provides an evaluation of the adversary’s current capabilities to facilitate the planning and resource allocation. When applied to the military field, it is the only one to be conducted during the activities and not before.

Intelligence is at the basis of decision-making, and decisions are efficient if they are supported by appropriate information. For this reason, the gathering of data becomes one of the pillars of intelligence activities. As such, it is highly relevant to understand the application and functionality of the various Intelligence Collection Disciplines.

2. Human Intelligence

Human Intelligence (HUMINT) is one of the oldest methods of data collection. Until the technological revolution of the late 20th century, it has been the primary intelligence source, and for most countries, it still remains the stronghold of their intelligence collection activities. HUMINT plays a key role in understanding the intent of the enemy and, even if it requires more time, is still the cheapest and most efficient solution.

HUMINT is the collection of information about adverse activities (political, military, economic, etc.) through human sources. It can be done openly, interviewing witnesses, suspects, and Persons of Interest, or through clandestine and covert means (espionage). The public perception of this discipline is usually related to clandestine activities. However, most of the raw information used to produce this intelligence is collected through interrogations, in the case of neutral or hostile people, and interviews, when it comes to allies. Human intelligence includes different activities, ranging from the exploitation of agents and sources to counter-interference. These activities can be summarized as follow:

  • Overt operations where military attachés and diplomatic personnel liaise with allied counterparts, members of official delegations, and ad hoc personnel. These activities include the exploitation of unclassified publications and documents, conference materials and hearings, and information from specific sources such as refugees, prisoners of war, and people who travelled to countries of interest.

  • Sensitive operations which use the same methods as overt activities, but the sponsor’s identity must remain protected from disclosure as it can compromise other intelligence operations, or cause security threats to the country.

  • Clandestine operations which include covert agents, spies recruited or volunteers that provide crucial information or who successfully infiltrate an organization with a cover story. This case is the rarest; however, it is not uncommon for these agents to move into working positions that allow gathering political, technical, or economic information for their governments.

The collectors need time to acquire information and validate the source. They must have a broad knowledge of the psychological aspects of human behavior to be able to motivate and persuade people and understand their attitude and honesty. The HUMINT collectors can be divided into official covers (OCs), intelligence and diplomatic agents sent abroad as part of the diplomatic personnel, and non-official covers (NOCs), agents without diplomatic immunity that, due to their non-diplomatic role, can infiltrate more easily in networks and go unnoticed.

Pic.2. Source: Intelligence101

Overall, human sources have more weaknesses than technical ones. A human can lie or be a double agent. For this, it is preferable to combine technology and HUMINT to produce a greater effect. These tools are not interchangeable, and a combination is always the best solution.

3. Signals Intelligence

Signals Intelligence (SIGINT) plays an important role in national security. It derives from the interception and elaboration of electromagnetic signals and electronic transmissions coming from the enemies’ tools and collected from different platforms (such as ships, planes, ground sites, or satellites) to monitor transmissions from terrestrial facilities and communications satellites. Its main purpose is to detect possible threats, discover capabilities, intentions, and actions of adversaries and intercept their movements to find the most effective action to implement and ensure readiness to tackle current and future threats. Unmanned aerial vehicles (UAVs), equipped with infrared sensor cameras, ground stations, and synthetic aperture radar systems are able to capture raw information that is subsequently interpreted and analysed to be used for real-time decisions.

Pic.3: SIGINT Systems. Source:

SIGINT is composed of three sub-disciplines, based on the type of the detected signal:

  • Communications Intelligence (COMINT) refers to the interception of communications transmission using cryptographic methods and device-to-device transmissions which target voice or text messages in their different formats, as well as videos, teleprinter traffic, and Morse code. Information can be collected from airwaves, cables, fiber optics, or other transmission means. COMINT capabilities are a crucial asset for a military force on battlefield to help detect enemy’s intentions and facilitate command actions through communications.

  • Electronic Intelligence (ELINT) includes the interception of non-communication transmissions made by radar systems and other electromagnetic radiation. The tools used are generally owned by governments; for this reason, these sources are highly classified and protected. ELINT is used to identify the location of an emitter, determine its peculiarities, and infer the characteristics of supported systems. ELINT can be both tactical and technical. In the first case, the equipment is associated with a weapon system, that enables a passive geo-localization useful to detect enemy radars’ location and capability. For technical operations, enemy radars are captured to understand how defence systems work and to identify new radars and new operational equipment.

  • Foreign Instrumentation Signals Intelligence (FISINT), can intercept foreign electromagnetic emissions associated with the testing and deployment of foreign aerospace, surface, and subsurface vehicles, and weapons system to determine their performance. This discipline includes signals from telemetry, electronic interrogators, command systems, and video data links to provide relevant information about operational characteristics such as system operation, fuel usage, staging, and other crucial parameters.

4. Imagery Intelligence

Imagery Intelligence (IMINT), sometimes referred to as Photographic Intelligence (PHOTINT), is a product of imagery analysis that can derive from visual photography, infrared, radar sensors, lasers, and electro-optics, as well as imagery gathered via satellite. It is obtained from hard-copy or soft-copy imagery.

In the first case, we speak about papers or film, in the other, imagery is displayed on electronic devices. Broadly used during the World Wars to take photographs from airplanes, IMINT provides significant benefits to an enemy State that wants to gather intelligence data. Only one meter of imagery is sufficient to map key areas and conduct detailed analyses of terrain, industrial facilities, and equipment, provide geolocation accuracies for weapons systems targeting, and detect relevant activities. In 1992, the Open Skies Treaty established a regime of unarmed aerial observation over the territory of its signatories to promote openness and transparency in their military activities.

Imagery also has several limitations. It can be undermined by darkness and adverse weather. This is the best time for the target to conduct activities without the risk to be observed. In addition, being aware of being targeted by imagery systems, camouflage, concealment, and deception (CC&D) techniques can be used to confuse the activities or provide a misleading image to the observing party. With the efficient use of CC&D, the adversary can make erroneous assumptions about the observed capabilities and activities. Nowadays, even though more and more nations have access to IMINT, it is still a privileged form of collection, as it depends on highly sophisticated technology able to overcome adverse natural phenomena.

IMINT has laid the basis for the development of a new discipline: the Geospatial Intelligence (GEOINT). It is the fusion of imagery with geospatial information to describe, assess, and visually depict physical and geographical features of security-related activities on the Earth’s surface and it is produced through a combination of mapping, imagery, charting, and geospatial information associated with a specific location. Advances in technology and the use of geospatial data allowed the integration of more sophisticated capabilities for visualization, analysis, and dissemination of the operational environment views. GEOINT can be used also for non-security purposes, for example, to track geographical changes and features (soil erosion, agricultural land usage, etc.) or weather conditions.

There are several ethical and privacy concerns associated with IMINT and GEOINT. Technologies can collect and analyze a large amount of data about individuals and communities, including information about their location, movements, activities, political affiliation, religious beliefs, and personal habits. This data can be used to track individuals or groups, monitor people’s behavior, potentially violate their privacy as well as impact civil liberties such as freedom of movement, association, and expression.

5. Measurement and Signature Intelligence

It is still a not very well-known discipline and is often used to complement other types of intelligence. It has become ever more important following the growing interest in the spread of weapons of mass destruction. In fact, this discipline concerns weapons capabilities and industrial activities and could be used to help identify chemical weapons or detect the specific characteristics of unknown weapons systems, among other things.

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MASINT is comprised of five sub-disciplines:

  • Radar intelligence that uses a special radar technique to collect high-resolution images with the purpose of identifying fixed and mobile targets, even submarine or underground.

  • Frequency intelligence suitable for data deriving from electromagnetic emissions transmitted by weapon systems.

  • Electro-optic intelligence, which gathers data from infrared or ultraviolet emissions to allow the identification of different elements, from infrastructures to hydrogeological systems.

  • Geo-physical intelligence which involves phenomena transmitted through the earth (i.e., water, atmosphere, and ground) such as sounds, pressure waves and vibrations, and magnetic disturbances.

  • Nuclear intelligence that monitors (remotely or during on-site inspections) features related to the nuclear sphere, from explosions to, reactors, radiation, and facilities.

6. Open-Source Intelligence

Nowadays, Open-Source Intelligence (OSINT) has become a fundamental and indispensable work tool in many environments and professional sectors. It represents the set of activities, acquired through legal means, aimed at searching, collecting, evaluating, and analyzing publicly available sources and information. Even though OSINT has become popular with the advent of the internet and digital media, it can be produced from information found in a wide range of formats and sources such as the media (newspapers, radio, television, etc.), professional and academic records (papers, conferences, professional associations, etc.), non-classified government data (reports, hearings, speeches, etc.), internet (online publications, blogs, social media websites) and grey literature (technical reports, unpublished works, etc.).

Social Media Intelligence (SOCMINT) can be considered a sub-discipline of OSINT, that allows the monitoring of content, messages, and other relevant data on social media platforms, such as Facebook and Instagram.

With the spread of electronic databases, it has become increasingly simple to collect large quantities of data and organize information to meet specific needs. OSINT is generally more accurate and may be the only information available in the early stages of a crisis or emergency.

Some factors can undermine open-source intelligence collection. For example, censorship may limit the publication of key data needed to have a full understanding of enemies’ actions. On the contrary, the growing number of online databases increases the capacity of adversaries and competitors to acquire a notable amount of information in a very short time. In fact, the more open a society is, the more it can be targeted. Also, the press could be used as a tool to defect the adversaries. If on the one hand, the internet has significantly increased the amount of accessible information, on the other hand, it poses problems regarding verifying reliability. To remedy this problem, specialists often use databases or sources available for a fee, which are already considered more reliable at the outset.

7. Technical Intelligence

Technical Intelligence (TECHINT) aims to assess, through specially trained personnel, the technical and scientific capabilities of the enemy, his strengths, and weaknesses, to be able to neutralize an adversary’s technological advantages, plan operations, and the necessary countermeasures, and avoid that the troops are taken by surprise. Information is therefore collected on the research and development of the enemy’s equipment, on its technical-scientific capabilities, on the weapon systems it possesses, and on the materials it can use. TECHINT includes elements of IMINT, MASINT, and SIGINT and it may also intersect with HUMINT.

Closely related to TECHINT is scientific intelligence, or intelligence on the development of new weapons and techniques. This discipline was already used during World War II when the two rival factions conducted technical and scientific intelligence operations against one another. It then proliferated during the Cold War, thanks to the scientific developments that improved weapons and surveillance technology.

8. Source’s reliability and information credibility

Failure to evaluate and verify the sources and information characteristics may contribute to intelligence failure, whether we are referring to a human source or an automatic sensor. As a result, the need for rating sources and the information they provide. Evaluating sources helps in recognizing whether the information included in the research is credible. Sources can be divided into primary and secondary, based on the factor of proximity. A primary source conveys direct knowledge of an event or activity to the analyst. A secondary source uses information doubly extrapolated. The more steps there are between the information and the source, the greater the probability that errors or distortions will occur. Following the evaluation of the sources is important to assess the substance of the report. The factors of plausibility and accuracy should always be taken into account. In addition, the parameter of deception has also to be considered to recognize activities conducted to mislead.

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The most widely used model to classify the sources from which the information received comes, in particular in NATO context, is the one in which the sources are classified in order of decreasing reliability, from A to E, where F is intended for the case where evaluation cannot be made. The information is ranked in decreasing order as well, from 1 to 5, where 6 is used to depict judgment that cannot be made. A fully trusted source, such as a COMINT operation, can be rated as A. However, if other intelligence has determined this information to be false, it may be rated as 5, meaning notably false. The report will therefore be classified as A-5. When it comes to a human source, if the person refers to a technically complex topic, and the expertise of the subject in question is unknown, it may be the case to reduce the reliability of the source. In addition, sources might be habitual liars. In this case, its reliability rating may be E, but if the reports are confirmed by other independent sources, the overall rating would be E-1. In general, most intelligence reports that are rated in the middle, meaning B-2, are considered.

9. Conclusions

Intelligence-driven decisions are at the heart of many operations across the government, military, and critical infrastructure sectors, allowing the collection, process, and analysis of all forms of signals and information useful for operational success. After having analyzed in detail every discipline, it can be said that merging data from multiple sources, such as satellite imagery, ground-based sensors, and human sources reports is the best approach to provide a comprehensive understanding of a given situation or threat. In the past, less technologically capable nations have been unable to gain access to certain types of information. Even though the situation is changing, and products are becoming more readily available, due to the high cost of some technologies, HUMINT is still the discipline prioritized by many less-developed countries. However, overall, all disciplines often depend on HUMINT to be effective. MASINT needs it to gather evidence and samples, and SIGINT to acquire codes from the field or to place technical monitoring devices in a certain location.

Thanks to the incredible advances in technology and communication systems is it easy to be exposed to a large amount of information. It’s the task of the analyst to select the most reliable information to be trusted and considered for influencing decision-making processes.

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An introduction to the main Intelligence Collection Disciplines
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  • Mirco Lapi, Open Source Intelligence: metodologie e strumenti per investigare il web, Edizioni Themis, 2021 p. 13-26.

  • Mark M. Lowenthal, Robert M. Clark, The five disciplines of intelligence collection, 2016.


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