August 14, 2003 (by Stefaan Vanhastel) - U.S. Air Force leaders are close to a decision on a sweeping, short-term upgrade to the smart bomb inventory that would equip the weapons with simple data links to allow them to track moving targets.
Under the Affordable Moving Surface Target Engagement (AMSTE) program, an AMSTE-equiped JDAM test-fired from an F-16 and guided by an E-8C JSTARS struck within three meters of a moving truck.
The Affordable Moving Surface Target Engagement (AMSTE) program aims to show that a remote ground moving target indicator (GMTI) radar and a synthetic aperture radar (SAR
) can feed tracking data on moving targets to smart bombs equipped with relatively low-technology data links. The AMSTE is a nearly $50 million program led by the Defense Advanced Research Projects Agency (DARPA) and the Air Force Research Laboratory (AFRL) in Rome, N.Y. with Northrop Grumman as main contractor.
Now that the program is nearing the end of a three-year demonstration phase, the Air Force is seeking to include AMSTE in the baseline or spiral requirements for things like Small Diameter Bomb (SDB) and next-generation JDAM
(Joint Direct Attack Munition).
However, the AMSTE concept requires investing in a communications architecture that could be difficult to expand as the Joint Tactical Radio System (JTRS) is developed over the next decade. The long-term goal under the JTRS program is to create a system that would allow, for example, a ground controller tracking a moving target to upload new coordinates directly to a falling smart bomb. The architecture for a weapons data link system remains undefined under the JTRS program, which could mean that AMSTE could be uncompatible with the JTRS network. So far, the government has resisted defining an architecture for weapons data links partly because it's not clear if the technology has matured enough.
On August 12, 2003, Northrop Grumman announced that AMSTE provides adequate performance even without the benefit of a SAR. The company showed in a July 24 flight test that it could obtain adequate targeting accuracy using a single GMTI radar track on a moving target. The demonstration involved a GMTI-equipped E-8C Joint Surveillance Target Attack Radar System (JSTARS) providing targetting data data to an F-16 equipped with an inert, 2,000-pound, seeker-less, data link-equipped JDAM. The F-16, flying at 20,000 feet, released the weapon nearly six miles away from the target. Joint STARS directed the JDAM to a point where it engaged the truck, which was traveling at 23 mph, shortly after the truck passed another vehicle at an intersection. The weapon struck within three meters of the target, well inside the lethal zone of a live JDAM.