What Is Signals Intelligence? Understanding SIGINT (2024)

By Dr. David James Kritz|07/23/2024

Signals intelligence (SIGINT) is one of the central intelligence disciplines, focusing on collecting and analyzing signals that contain data or information. These signals can include communications (such as phone calls and emails) and electronic emissions (such as radar and telemetry).

Through sophisticated analytic techniques, this information is then converted into actionable intelligence. For example, SIGINT is used to determine the geolocation of a signal's origin, which helps in identifying the location and movements of adversaries.

SIGINT Capabilities and Its Application to Intelligence Gathering

Signals intelligence, although its application has been shrouded in secrecy with some of the nation's highest classification levels, is a form of intelligence gathering that has been crucial throughout history. For instance, the U.S. collected foreign communications information from the Soviet Union by targeting East German airbases during the Cold War.

In modern warfare, SIGINT relies on technology to gain access to communications such as voice interception. By using special equipment and technology for signals intelligence, a nation can gain a better understanding of an opponent's military by recognizing and analyzing intentions and threats.

SIGINTis a powerful tool that enables passive listening to communications, allowing for the gathering of intelligence at various levels. At the strategic level, it helps determine the enemy’s intentions and foreign adversaries' capabilities. At the operational and tactical levels, it identifies the locations of enemy forces and their military equipment during military operations.

Subsets of SIGINT

As SIGINT is one of the more expansive intelligence disciplines, there are several subsets that focus on electronic intelligence:

• Communications Intelligence (COMINT)
• Electronics Intelligence (ELINT)
• Foreign Instrumentation Intelligence (FISINT)

It is important to note that signals intelligence is different than signature intelligence. Signature intelligence is a specialized subset of signal intelligence that focuses specifically on identifying and analyzing unique characteristics or "signatures" of these signals.

COMINT

Communications intelligence is an essential tool that focuses on communications between people. COMINT is used for gathering information from communication tools such as:

• Radio traffic, including Citizen Band (CBs) radios on trucks and walkie-talkies
• Communications occurring online or in online social platforms
• Telephone communications, including texting

ELINT

ELINT is information gathered from electronic signals that are non-communication signals in nature. According to Trenton Systems, ELINT “signals include radio or electromagnetic pulses and signals that are emitted from radars, missiles, guidance systems, and aircrafts.”

ELINT as a subset of SIGINT also has subsets, including:

• Technical ELINT (TechELINT)
• Operational ELINT (OpELINT)
• Telemetry ELINT (TELELINT)

The National Security Agency (NSA) says that TechELINT “describes the signal structure, emission characteristics, modes of operation, emitter functions, and weapons systems associations of such emitters as radars, beacons, jammers, and navigational signals.” TechELINT is vital as it helps determine the intentions and capabilities of the emitters.

OpELINT centers on supporting operational planners within the battlefield. OpELINT focuses on “locating specific ELINT targets and determining the operational patterns of the systems,” Trenton Systems observes.

FISINT

Foreign instrumentation signals intelligence was previously labeled telemetry intelligence (TelELINT). It concerns the monitoring of foreign communications and testing of ballistic missiles, beacons, satellites, space vehicles launches and weapon systems, and video data links, according to Trenton Systems.

Foreign instrumentation signals come from beacons, missile and satellite command systems, and telemetry, according to the NSA. Telemetry collects technical information from foreign instruments’ signals onsatellites and missiles that analysts may use to determine an adversary’s intentions and improvements of weapons systems.

The NSA and Its Role in Signals Intelligence

Established in 1952, the NSA is responsible for the collection of U.S. SIGINT and safeguarding U.S. communications from being intercepted. The NSA “provides foreign signals intelligence to our nation's policymakers and military forces. SIGINT plays a vital role in our national security by providing America's leaders with critical information they need to defend our country, save lives, and advance U.S. goals and alliances globally.”

As SIGINT intercepts private communications, protecting the rights and civil liberties of a U.S. citizen is paramount when balancing national security concerns with privacy concerns. As with the other intelligence disciplines,signals must be collectedethically and within the constraints of state and national laws.

The NSA takes into accountcivil liberties, privacy, and transparencyas they are “held accountable for upholding the laws of the land while providing critical foreign intelligence information to keep America and its allies safe and secure…NSAis requiredby law to protectthefreedoms, civil liberties, and privacy rightsof Americanswhile accomplishing important national security missions.”

Why SIGINT Is Important to National Security

The information collected from SIGINT is recorded right from the source, which is an advantage because human intelligence (HUMINT) is prone to bias, poor analyses, or even lies. As a result, the information gained directly from the target is more often truthful.

SIGINT collection is also faster than human intelligence (HUMINT). It allows intelligence customers to more quickly receive answers to their priority intelligence requirements – essentially their critical questions – in regard to threats posed by internal organizations as well as adversarial countries.

Also, SIGINT is important to protecting the security of our nation. It enables intelligence agencies to thwart threats and find opportunities due to SIGINT’s ability to help determine an adversary’s intentions through intelligence gathering (commonly referred to as collection).

SIGINT acts as a conduit for indications and early warnings of trouble, which is useful for ensuring national defense. The data and information collected from SIGINT can help senior leaders make more informed decisions by using the data gathered by analysts to predict probable future events.

Intelligence derived from signals intelligence is complimentary to other intelligence agencies and disciplines such as human intelligence, geospatial intelligence, and open-source intelligence. This combination adds credibility and depth to intelligence reports by delivering a more comprehensive depiction of a situation to help intelligence analysts better analyze and anticipate potential threats and determine counterintelligence purposes. Since signals intelligence is passive, the target is often unaware that collection is occurring.

Jamming

Jamming is a standard part of electronic warfare and is one of the obstacles that impede SIGINT operations. Jamming occurs when foreign powers use interfering signals, which are highly concentrated energy, that are directed at another's radio detection and ranging (RADAR) equipment. This interference blocks the receiver's electronic systems, disrupting their ability to function properly.

The emphasis of jamming is to block the receiver and not the transmitter. During times of conflict, jamming can negatively affect SIGINT missions on the battlefield, including air and ground SIGINT sensors.

To mitigate jamming, technological advances and specialized equipment such as what is used in the MC-12W Liberty aircraft, employ countermeasures such as frequency hopping. It may be difficult for SIGINT operators to know when jamming is occurring or if it is from unintentional interference, atmospheric conditions, faulty equipment, or a combination of factors.

Intelligence Studies Degrees at AMU

American Military University (AMU) offers various intelligence studies degrees, including an online bachelor’s degree in intelligence studies and an online master’s degree in intelligence studies. The courses for these programs are taught by faculty with extensive backgrounds in intelligence and national security.

Courses in these degree programs are intended to provide adult learners with a deep understanding of intelligence operations, analysis, and application. Students in these programs will also learn the critical thinking and analytical skills needed to seek various roles in intelligence.

In addition, AMU’s flexible online format allows students to balance their studies with professional and personal commitments.

Bachelor of Arts in Intelligence Studies

The online bachelor’s degree in intelligence studies is designed to broaden students' knowledge of the Intelligence Community. The program's learning objectives include understanding the intelligence cycle and applying ethical standards to intelligence work.

Students will have the chance to gain hands-on experience by evaluating data, producing comprehensive intelligence reports, and utilizing advanced analytical techniques to solve complex problems. This practical approach helps to prepare students to effectively support decision-making processes when they seek roles in various intelligence and national security agencies.

Master of Arts in Intelligence Studies

The online master’s degree in intelligence studies is intended to provide an advanced understanding of strategic intelligence analysis, collection, and operations. This program focuses on examining the evolution, structures, functions, capabilities, and activities of the U.S. Intelligence Community.

Students can learn about the intelligence cycle, including planning, data collection, analysis, production, and dissemination. They will also assess traditional and nontraditional threats to national and international security in order to gain the knowledge to pursue leadership roles in the intelligence field.

For more information about our intelligence studies degrees, visit our program page.