The discipline of collecting, analyzing, and utilizing information, or intelligence, gathered from an enemy state or region. This kind of information gathering and analysis has existed since antiquity, but it was not until the advent of computers, unmanned planes, radar, and satellite imagery that intelligence gathering became the huge undertaking it is today. In the United States there are 17 intelligence gathering agencies, most notably the Central Intelligence Agency (CIA), the National Security Administration (NSA), and the Federal Bureau of Investigation (FBI). These agencies are all members of the United States Intelligence Community, founded in 1981.
"COBRA DANE, an intelligence-gathering phased-array RADAR system specially constructed to monitor Soviet ballisitc missile testing, June 1977" by Sgt. Robert S. Thompson is licensed under Public Domain.
Encyclopædia Britannica Online
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http://www.britannica.com/EBchecked/topic/289765/intelligence, accessed February 04, 2015.
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intelligence.gov
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http://www.intelligence.gov/mission/member-agencies.html, accessed February 4, 2015.
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