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).
