Stealth technology is a sub-discipline of military tactics and passive and active electronic countermeasures which covers a range of methods used to make personnel, aircraft, ships, submarines, missiles, satellites, and ground vehicles less visible (ideally invisible) to radar, infrared, sonar and other detection methods. To be called RF stealth technology it is also concerned with reducing infrared and acoustic emissions. A stealth vehicle must avoid radiating any other detectable energy, such as from onboard radars, communications systems, or RF leakage from electronics enclosures.