Active radar homing

Active radar homing (ARH) is a missile guidance method in which a missile contains a radar transceiver (in contrast to semi-active radar homing, which uses only a receiver) and the electronics necessary for it to find and track its target autonomously. The NATO brevity code for an air-to-air active radar homing missile launch is fox three. There are two major advantages to active radar homing: As the missile is tracking the target it is going to be much closer to the target than the launching platform during the terminal phase, thus the missile's tracking can be much more accurate and better resistant to electronic countermeasures. Active radar homing missiles have some of the best kill probabilities, along with missiles employing track-via-missile guidance. Because the missile is totally autonomous during the terminal phase, the launch platform does not need to have its radar enabled at all during this phase, and in the case of a mobile launching platform like an aircraft, can actually exit the scene or undertake other actions while the missile homes in on its target. This is often referred to as fire-and-forget capability and is a significant advantage that modern air-to-air missiles have over their predecessors. Because most missiles are powered by rocket motors, they have no on-board electricity generation capability. This means that active radar-guided missiles usually rely on battery power for the radar transmitter, significantly limiting its power - although this can be mitigated by employing the designs described below. Because a complete radar system is implemented, an active system will be more expensive than a semi-active system if all other factors are equal. Many missiles employing passive homing have an additional capability: if the target does attempt to use noise jamming, the missile can home in on the target's radiation passively (home-on-jam). This gives such missiles improved performance against noise jamming targets and allows anti-aircraft munitions to attack targets they would not otherwise be able to fire on effectively.