Raytheon Systems revealed a series of planned upgrades to the Paveway IV “smart” 500-pound bomb for the UK Royal Air Force (RAF). In British service since 2008, the weapon has been dropped more than 1,000 times, said T.J. Marsden, chief engineer of weapons systems for Raytheon’s UK subsidiary. He described Paveway IV as the UK’s primary air-to-ground weapon.

The upgrades form part of the UK Ministry of Defence’s Selected Precision Effects At Range (Spear) program to provide various new and improved air-launched weapons. The potential Paveway IV developments form Capability 1 of the Spear program and are threefold, Marsden explained. The first is a low-collateral-damage warhead. “We have investigated more than a dozen designs, making extensive using of hydrocode modeling. Now we will build a prototype,” he said. Marsden said that the design work has benefitted from input by Cranfield University, QinetiQ and a couple of smaller companies.

Raytheon Systems has also teamed with QinetiQ on a penetrator warhead for the Paveway IV. Such warheads have previously been associated with larger weapons, but Marsden said that the pair has done risk reduction studies on “a novel, discarding-shroud design.” It is ready for development.

Paveway IV features a dual-mode semi-active laser/GPS seeker, and Marsden noted that the GPS seeker had already been improved in the second production lot. Now Raytheon Systems is ready to adapt its GPS anti-jam technology to the weapon, and to others in the Paveway series, using a tail-mounted installation. But the third development being pursued for the Spear program concerns the laser seeker, which has been digitized and provided with a wider field of view, so that the weapon can be employed against high-value targets moving and maneuvering at speed, Marsden explained. “We have introduced proportional navigation during the laser guidance portion of [the bomb’s] flight. This will allow aircrew to put a laser spot on the target and leave it there,” he added.

Prototype seekers are now in flight-test by Raytheon Missile Systems in the U.S., which is also adapting it to the larger Enhanced Paveway II bomb.