Surveillance

In a military context, surveillance is the process of observation of aerospace, surface, or subsurface areas, places, persons, or things. This process may use technical sensors, native human abilities or both. Surveillance differs from reconnaissance in that surveillance is a continuing process, where reconnaissance is carried out by specific missions.

For example, a surveillance system might use a ground surveillance radar to detect, on a 24-hour basis, activity along a border. Reconnaissance of the same border would involve a ground patrol or overflight along it.

Intelligence, in the context of intelligence, surveillance, and reconnaissance is the synthesis and analysis of information produced by surveillance and reconnaissance.