Anti-Radiation Missile (ARM)

In modern day warfare, air supremacy is critical to accomplish battlefield objectives. The suppression of an enemy's air defenses is of paramount importance if air supremacy is to be achieved. A number of individual weapons have been developed for this purpose. There are two types of defensive surface-to-air missile sites that require surveillance and suppression: non-radiating sites and intermittently radiating sites. Also, the present High Speed Anti-Radiation Missile (HARM) is designed for the destruction of a radiating radar antenna only, and is not therefore effective for the destruction of an entire missile site or other sites of military interest. No existing weapon system is capable of concurrently searching for, surveying, identifying, and destroying radar antennas, missile launchers, and support equipment and facilities for both types of missile sites.

In the field of missile guidance there are many known tracking systems for directing a warhead to a selected target. The known systems rely on guidance techniques which range from programmed guidance, to in-flight target search, detection, and selection. However, none of the known systems comprise passive systems capable of tracking a pulsed radiation source by receiving emitted pulse radiation and determining and angular co-ordinates of the source, through the use of closed loop monopulse techniques. Tracking systems which receive and utilize emitted radiaton for target tracking purposes are particularly useful in anti-radiation missile guidance.

One type of missile utilized as an anti-radiation device is a warhead bearing, rocket propelled missile which is initially launched ballistically from a piloted aircraft, or other suitable means, into a field of radiation, with missile guidance and directional control being subsequently imposed for the terminal portion of the missile's trajectory in order that the missile may "home" on the radiation source to a miss distance compatible with a given kill radius of the missile's warhead.

It is well known in the art that an anti-radiation missile (ARM) is adapted to home on radio frequency (RF) signals radiated so that an explosive charge carried by such a missile may destroy a radar. To accomplish such homing, the guidance system in an ARM missile may be designed to lock onto the leading or trailing edge of radar interrogating pulses, as well as midpulse samples of such pulses. It is therefore desirable that, in order to increase the chance of survivability of a radar attacked by an ARM missile, decoys located in the vicinity of the radar be actuated to generate RF signals to cause the guidance system in an attacking ARM missile to home on an apparent source spaced from the radar.

Thus, RF signals from the decoys are synchronized with the interrogating signals from the radar so that the RF signals from the decoys produce pulses overlapping (in power and time) the interrogating pulses produced by sidelobes of the antenna in the radar. Consequently, the guidance system in an attacking ARM missile is inhibited from using the leading or trailing edges or midpulse samples of the radar's interrogating pulses to accurately derive guidance commands. Further, the decoys are caused to "blink". That is to say, the position in time, relative to the defended radar of each of the decoys is periodically altered. As a result of such "blinking" the aim point of the ARM is caused to wander, thereby preventing the ARM from homing on the radar or any one of the decoys.

There existed a significant need for an improved air defense destruction missile weapon system which is fully integrated and specifically designed to accomplish the destruction of an entire missile site of an enemy's air defenses. The present invention fulfills these needs and provides further related advantages such as high attitude surveillance and interoperability capability with other combat aircraft performing air defense suppression missions.