Active radar homing is a type of missile guidance where a guided missile contains a radar transceiver and the electronics necessary for it to find and track its target autonomously. There are two major advantages to active radar homing: This article or section should be merged with Guided missile Military missile systems use a variety of methods to guide the missile to its intended target. ... A guided missile is a military rocket that can be directed in flight to change its flight path. ... This long range radar antenna (approximately 40m (130ft) in diameter) rotates on a track to observe activities near the horizon. ... In computer networking, the term transceiver (sometimes abbreviated to TCVR) is a device that performs, within one chassis, both transmitting and receiving functions that is in a common housing, sometimes designed for portable or mobile use, uses common circuit components for both transmitting and receiving which provides half-duplex operation. ...

• Because the missile is tracking the target, and the missile is typically going to be much closer to the target than the launching platform during the terminal phase, the tracking can be much more accurate and also have better resistance to ECM (jamming). Active radar homing missiles have some of the best kill probabillities, along with missiles employing track-via-missile guidance.
• Because the missile is totally autonomous during the terminal phease, the launch platform doesn't 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 great advantage that modern air-to-air missiles have over their predecessors.

Also, two major disadvantages: ECM is an abbreviation of: Electret condenser microphone Electro chemical machining Electronic countermeasures Electronic control module Elliptic curve method (integer factorization) Enterprise content management Error correction mode (fax protocol) Extracellular matrix See also: ECM (record label) This is a disambiguation page — a navigational aid which lists other pages that might... Jamming is an electronic warfare (EW) technique to limit the effectiveness of an opponents communications and/or detection equipment. ... Computer games, simulations, models, and operations research programs often require a mechanism to determine statistically whether the engagement between a weapon and a target resulted in a kill. ... Track-via-missile (or TVM) refers to a missile guidance technique which combines many of the best features of semi-active radar homing (SARH) and radio command guidance. ... Fire and forget is the military term for a type of missile which does not require further guidance after launch such as illumination of the target, and can hit its target without the launcher being in line of sight of the target. ... A US Navy VF-103 Jolly Rogers F-14 Tomcat fighter launchers an AIM-54 Phoenix long-range air-to-air missile. ...

• Since the missile has to contain an entire radar transceiver and electronics, it was until recently difficult to jam all of this into a missile without increasing its size and weight. Even with today's miniaturisation making this possible, it's quite expensive to make these missiles since all that sophisticated electronics gets blown up when the missile explodes.
• There is very little chance that a target with any sort of decent radar warning receiver won't know that a missile is about to hit them. This gives them sufficient time to take evasive action. However, given the accuracy of this homing method, unless the target is especially maneuverable or the missile is not, there may not be much they can do to avoid being intercepted.

Many missiles employing this type of guidance have an extra trick up their sleeves; if the target does attempt to jam them using some kind of ECM, they can in effect turn into an anti-radiation missile and home in on the target's radiation passively. This makes such missiles practically immune to ECM, in addition to removing the second disadvantage. Since they already have the radar receiver on board, this should not be a terribly difficult feature to add (at least, it requires extra processing logic but little extra hardware). Typically fitted to military aircraft, radar warning receivers (RWR) detect the radio emmissions of radar systems, whether ground-based or on-board other aircraft. ... ECM is an abbreviation of: Electret condenser microphone Electro chemical machining Electronic countermeasures Electronic control module Elliptic curve method (integer factorization) Enterprise content management Error correction mode (fax protocol) Extracellular matrix See also: ECM (record label) This is a disambiguation page — a navigational aid which lists other pages that might... An anti-radiation missile is a missile which is designed to detect and home in on the emissions of an enemy radar installation. ...

Active radar homing is rarely employed as the only guidance method of a missile. It is most often used during the terminal phases of the engagement, mainly because since the radar transceiver has to be small enough to fit inside a missile and has to be powered from batteries, its range is limited. To overcome this, most such missiles use a combination of command guidance with an inertial navigation system (INS) in order to fly from the launch point until the target is close enough to be detected and tracked by the missile. The missile therefore requires guidance updates via a datalink from the launching platform up until this point, incase the target is maneuvering, otherwise the missile may get to the projected interception point and find that the target is not there. Sometimes the launching platform (especially if it's an aircraft) may be in danger continuing to guide the missile in this way until it 'goes active'; in this case it may turn around and leave it to luck that the target ends up in the projected acquisition 'basket' when the missile goes active. It is possible for a vehicle other than the launching platform to provide guidance to ths missile before it switches its radar on; this may be other, similar fighter jets or perhaps an AWACS. Command guidance is a type of missile guidance where a ground station or aircraft relay signals to a guided missile via radio (or possibly through a wire connecting the missile to the launcher) and tell the missile where to steer in order to intercept its target. ... An inertial navigation system measures the position and altitude of a vehicle by measuring the accelerations and rotations applied to the systems inertial frame. ... In telecommunication, the term data link has the following meanings: The means of connecting one location to another for the purpose of transmitting and receiving data. ... A fighter aircraft is a military aircraft designed primarily for attacking other aircraft, as opposed to a bomber, which is designed to attack ground targets, primarily by dropping bombs. ... US Air Force E-3 Sentry AWACS aircraft is prepared for flight in November 1997 Cockpit of RAF E-3 Sentry undergoing upgrades Airborne Warning and Control System (AWACS) is a radar-based electronic system designed to carry out airborne surveillance, and C3 (command, control and communications) functions for both...

Examples of missiles which use active radar homing (all in their terminal phase) include:

• Russia - SA-5 'Gammon' (Almaz NPO S-200 'Volga')
• Russia - AA-12 'Adder' (Vympel R-77 'AMRAAMSKI')
• USA - AIM-120 AMRAAM

An S-200 missile on its launcher. ... The Russian R-77RVV-AE Missile (NATO designation: AA-12 Adder) is a medium range, air-to-air, radar-guided missile system. ... The AIM-120 Advanced Medium-Range, Air-to-Air Missile, or AMRAAM (pronounced am-ram), commonly known to air crews as the Slammer, is a new generation air-to-air missile, developed as the result of an agreement between the United States and other NATO countries (see below). ...