An upgrade to AGM-88 High-Speed Anti-Radiation Missiles, the HARM Control Section Modification, has been tested by the U.S. Air Force and Raytheon.

The modification features a new GPS/inertial measurement unit capability and increased resistance to counter-HARM tactics.

Raytheon said in the flight test, an AGM-88F with the modification --was fired by an F-16 against an emitter located outside a pre-planned zone of exclusion while a similar radiating emitter within the zone attempted to lure the missile to the decoy target.

The Harm missile ignored the decoy and successfully impacted where it was supposed to.

"HCSM provides the warfighter an effective, affordable solution that improves the probability of hit, defeats counter-HARM tactics and controls where the missile can and cannot fly," said Mike Jarrett, vice president of Raytheon's Air Warfare Systems.

Tests on the upgrade are continuing. Once completed, the Air Force will make a decision on fielding the new HCSM capability.

The AGM-88 is designed for use against surface-to-air missile radars, early warning radars and radar-directed air defense artillery systems. More than 4,000 HARMs have so far been employed in combat.