Anti-Fighter Missile Acoustic Homing Device

From PDI

Preface

The weapon-vs-protective measures race has never ceased. To date, anti-aircraft missiles have employed a variety of homing devices to successfully aim at and chase the airplane being attacked, namely, radar-based and infrared; in their turn, the airplanes have achieved sufficiently good rates of counteracting such homing devices, by confusing them, respectively, with radar-reflective chaff (which creates a radiowave-reflecting cloud obscuring the airplane) and infrared flares (which mimic the heat signature of the airplane's engines, luring the missile away from the actual airplane).

However, it should be noted that modern aircraft possess one more distinctive signature; namely, the acoustic one. Rapidly maneuvering jet fighter has no choice but to keep its engines revved up, producing noise over 140db in loudness, easily the loudest sustained sound that can be heard in battle conditions. And while it is sufficiently easy to produce a continuous false radar or infrared signature, it is nearly impossible to reasonably produce any more than a fleeting false acoustic signature.

Claims

1. A homing device for anti-aircraft missile utilizing an acoustic signature as a primary method for homing on the target aircraft.
2. An acoustic homing device as claimed in claim 1, specifically designed to target the aircraft with most prominent audio signatures, in particular, maneuvering jet fighters.
3. An acoustic homing device as claimed in claim 1, employing additional homing methods, such as infrared signature, during long range approach to the target, switching to the acoustic method in the vicinity of the target aircraft in order to minimize the possibility of false positives on the ground
4. An acoustic homing device as claimed in claim 1, consisting of a phased audio receiver array with a coupled computing device, capable of analyzing the incoming sound waves, filtering out the unwanted distractions such as those generated by the turbulence caused by the flight of the missile itself, and detecting the direction of the most loud sound source.

In layman's terms

Currently, the anti-aircraft missiles seek out the enemy planes in the sky using the fact that jet engines are, in fact, very hot. So they go for the hottest point in the sky. Which, unfortunately (for the missile) can be, in fact, the infrared flare jettisoned by the evasive aircraft. Well, if you ever had a jet fighter flying over your head, you should have noticed that the damn thing is VERY VERY LOUD! And, while it is easy to create a flare that will be hotter than the airplane, it is impossible to design the distraction that would be louder than the airplane, at least for a substantial time (yes you can make a louder sound with a sufficiently large "firecracker", yet only for a brief second, while the jet engine roars continuously).