GPS bombing a moving target

Ground Moving Target Engagement System Hits Tank With JDAM

In October, an F-16 armed with a Joint Direct Attack Mission bomb (guided by GPS) destroyed a moving, remotely-controlled M-60 tank. Just before weapon release, the tank crossed paths with several other vehicles, but the tacking system, called the Affordable Moving Surface Target Engagement (AMSTE) system, stayed on the scent.

The test team used two radar systems developed by Northrop Grumman Electronic Systems to track the tank. An APY-7 system installed on a Joint Surveillance Target Attack Radar System (Joint STARS) test-bed aircraft flew 100 kilometers from the target.

A prototype Joint Strike Fighter active electronically scanned array aboard a BAC 1-11 flew 35 kilometers from the target. The F-16, flying at 20,000 feet, was more than 11 kilometers from the target when it dropped the GPS-guided weapon.

As the JDAM fell, it received location information on the tank from the Joint STARS that was so precise that the live bomb hit the tank directly on its turret completely destroying the tank.

The system uses two seperate radars to track the target, calculates the coordinates, and continuously beams the updated target location to the JDAM unit on the bomb, which adjusts its flight path accordingly. Then the target goes ‘boom.’

The JDAM is going to be bomb-guidance system of choice for years, if not decades. There’s concern about jamming and attacks against the GPS sats that transmit to the recievers on the bomb units, of course, but the ability to hit a moving target with a coordinate-guided weapon is a major boost for our military.

For a PDF summary with diagrams and illustrations, check this DTIC site out.