Signals intelligence in the context of "Human intelligence (intelligence gathering)"

Akrotiri and Dhekelia (/ˌækroʊˈtɪəri ənd diˈkeɪliə/), officially the Sovereign Base Areas of Akrotiri and Dhekelia (SBA), is a British Overseas Territory that consists of two separate areas on the island of Cyprus. The areas, which include British military bases and installations that were formerly part of the Crown colony of Cyprus, were retained by the British under the 1960 treaty of independence signed by the United Kingdom, Greece, Turkey, the President of Cyprus and the representative of the Turkish Cypriot community. The territory serves as a station for signals intelligence and is thereby part of the United Kingdom's surveillance-gathering work in the Mediterranean and the Middle East.

Despite being under British control, Akrotiri and Dhekelia are integrated with the surrounding Cypriot communities and economies. The areas are notable for their strategic geopolitical value and rich environmental features, including the Akrotiri Salt Lake, a protected wetland. Education, policing, and healthcare services are provided in coordination with the Republic of Cyprus. The SBAs also play a significant role in intelligence and communications operations across the Eastern Mediterranean. Although not part of the European Union post-Brexit, the areas continue to be governed by protocols that align with certain EU laws to avoid disrupting the daily lives of residents.

The National Security Agency (NSA) is an intelligence agency of the United States Department of Defense, under the authority of the director of national intelligence (DNI). The NSA is responsible for global monitoring, collection, and processing of information and data for global intelligence and counterintelligence purposes, specializing in a discipline known as signals intelligence (SIGINT). The NSA is also tasked with the protection of U.S. communications networks and information systems. The NSA relies on a variety of measures to accomplish its mission, the majority of which are clandestine. The NSA has roughly 32,000 employees.

Originating as a unit to decipher coded communications in World War II, it was officially formed as the NSA by President Harry S. Truman in 1952. Between then and the end of the Cold War, it became the largest of the U.S. intelligence organizations in terms of personnel and budget. Still, information available as of 2013 indicates that the Central Intelligence Agency (CIA) pulled ahead in this regard, with a budget of $14.7 billion. The NSA currently conducts worldwide mass data collection and has been known to physically bug electronic systems as one method to this end. The NSA is also alleged to have been behind such attack software as Stuxnet, which severely damaged Iran's nuclear program. The NSA, alongside the CIA, maintains a physical presence in many countries across the globe; the CIA/NSA joint Special Collection Service (a highly classified intelligence team) inserts eavesdropping devices in high-value targets (such as presidential palaces or embassies). SCS collection tactics allegedly encompass "close surveillance, burglary, wiretapping, [and] breaking".

The National Reconnaissance Office (NRO) is a member of the United States Intelligence Community and an agency of the United States Department of Defense which designs, builds, launches, and operates the reconnaissance satellites of the U.S. federal government. It provides satellite intelligence to several government agencies, particularly signals intelligence (SIGINT) to the National Security Agency (NSA), imagery intelligence (IMINT) to the National Geospatial-Intelligence Agency (NGA), and measurement and signature intelligence (MASINT) to the Defense Intelligence Agency (DIA). The NRO announced in 2023 that it plans within the following decade to quadruple the number of satellites it operates and increase the number of signals and images it delivers by a factor of ten.

NRO is considered, along with the Central Intelligence Agency (CIA), NSA, DIA, and NGA, to be one of the "big five" U.S. intelligence agencies. The NRO is headquartered in Chantilly, Virginia, 2 miles (3.2 km) south of Washington Dulles International Airport.

An intelligence agency is a government agency responsible for the collection, analysis, and exploitation of information in support of law enforcement, national security, military, public safety, and foreign policy objectives.

Means of information gathering are both overt and covert and may include espionage, communication interception, cryptanalysis, cooperation with other institutions, and evaluation of public sources. The assembly and propagation of this information is known as intelligence analysis or intelligence assessment.

A reconnaissance aircraft (colloquially, a spy plane) is a military aircraft designed or adapted to perform aerial reconnaissance with roles including collection of imagery intelligence (including using photography), signals intelligence, as well as measurement and signature intelligence. Modern technology has also enabled some aircraft and UAVs to carry out real-time surveillance in addition to general intelligence gathering.

Before the development of devices such as radar, military forces relied on reconnaissance aircraft for visual observation and scouting of enemy movement. An example is the PBY Catalina maritime patrol flying boat used by the Allies in World War II: a flight of U.S. Navy Catalinas spotted part of the Japanese fleet approaching Midway Island, beginning the Battle of Midway.

Surveillance aircraft or observation aircraft are aircraft used for aerial surveillance. They are primarily operated by military forces and government agencies in roles including intelligence gathering, maritime patrol, battlefield and airspace surveillance, observation (e.g. artillery spotting), and law enforcement.

Surveillance aircraft usually carry limited defensive armament, if any. They do not require high-performance capability or stealth characteristics and may be modified civilian aircraft. Surveillance aircraft have also included moored balloons (e.g. TARS) and unmanned aerial vehicles (UAVs).

The Five Eyes (FVEY) is an Anglosphere intelligence alliance comprising Australia, Canada, New Zealand, the United Kingdom, and the United States. These countries are party to the multilateral UKUSA Agreement, a treaty for joint cooperation in signals intelligence. Informally, "Five Eyes" can refer to the group of intelligence agencies of these countries. The term "Five Eyes" originated as shorthand for a "AUS/CAN/NZ/UK/US Eyes Only" (AUSCANNZUKUS) releasability caveat.

The origins of the FVEY can be traced to informal, secret meetings during World War II between British and American code-breakers that took place before the US formally entered the war. The alliance was formalized in the post-war era by the UKUSA Agreement in 1946. As the Cold War deepened, the intelligence sharing arrangement was formalised under the ECHELON surveillance system in the 1960s. This system was developed by the FVEY to monitor the communications of the Soviet Union and Eastern Bloc; it is now used to monitor communications worldwide. The FVEY expanded its surveillance capabilities during the course of the "war on terror", with much emphasis placed on monitoring the Internet. The alliance has grown into a robust global surveillance mechanism, adapting to new domains such as international terrorism, cyberattacks, and contemporary regional conflicts.