Difference between semi-active, passive and active radar homing missile
This page compares semi-active radar homing vs passive radar homing vs active radar homing and mentions difference between semi-active, passive and active radar homing missile systems.
Radar homing guidance is most common form of guidance system used for anti-air missiles. Based on their working operation there are three types of radar homing missile systems viz. semi-active, passive and active.
Semi-active Radar Homing
Figure-1 depicts Semi-active Radar Homing working operation.
Following are the features of Semi-active Radar Homing.
• It uses only receiver where as target is illuminated by near by radar or some other external source.
• The reflected energy from the target is received by the receiver mounted on the missile.
• The computer connected with the receiver is used to determine relative trajectory of the target. This information is used by the missile system in order to intercept the target accurately.
• It is used for long air to air and ground to air missile systems.
• It is used for "all weather" guidance system as anti-aircraft system.
1st generation SAM used by the RSAF
Active Radar Homing
Figure-2 depicts Active Radar Homing working operation.
Following are the features of Active Radar Homing.
• It transmits the energy and receives the reflected energy. Unlike semi-active, above is done by missile itself as it houses both transmitter and receiver parts.
• No external source is needed in this radar homing system.
• AMRAAM air-to-air missile
• Exocet anti ship missile
AMRAAM AIM-120 is combination of both active and semi-active homing. It supports medium range of about 50 Km.
Passive Radar Homing
Figure-3 depicts Passive Radar Homing working operation.
Following are the features of Passive Radar Homing.
• It uses heat radiations from the target. The heat energy is being used by the missile to determine target's parameters.
• It is independent of any external guidance system.
• It only receives the signal and can not transmit the signal similar to semi-active radar homing system.
• Mistral deployed by the RSAF is a passive infrared homing guidance system.
• AIM9L/M passive IR homing guidance seeker
• Semi-active and active homing missiles can be detected easily.
• Passive homing missile is difficult to detect and easier to break lock.