A series of enhancements to Raytheon's Paveway IV precision-guided bomb are being readied for test, with a version carrying its own GPS anti-jammer likely to fly late this year or early in 2014.
The anti-jamming equipment will be retrofitable to Paveway II bombs and other munitions.
Other new Paveway IV upgrades will expand the weapon's launch acceptance region, allowing the bomb to be released earlier in a mission, along with a wider field-of-view laser seeker which is already in flight testing, and a new penetrating warhead. The Paveway IV will also be capable of striking moving targets.
Outlining its upgrade programme for one of the Royal Air Force's mainstay weapons at a London technology presentation for representatives of Raytheon UK, the UK Royal Air Force and the US military, Raytheon UK's Paveway IV chief engineer Terence Marsden stressed that all the new features will be made available without altering the weapon's mass, centre of gravity or external profile. The Paveway IV will remain in the 226kg (500lb) weight class and versions will be interchangeable with no change to aircraft integration. Crews in theatre will be able to break down weapons and interchange features.
Raytheon cannot comment further on the in-service timetable for any of its Paveway developments, but the updated weapon is believed to be earmarked for flight from 2018, when the UK is to introduce its first Lockheed Martin F-35B Joint Strike Fighters.
Already integrated with the RAF's Panavia Tornado GR4 force, the Paveway IV has been used during combat operations in Afghanistan and Libya. It is expected to enter service soon with RAF Eurofighter Typhoons.
The Paveway project highlights the urgency of developing technologies to counter inexpensive GPS jammers.
Units capable of jamming GPS signals over a 200m (650ft) to 300m radius are widely available online for as little as £20 ($30) - and are widely used on UK roads, by criminals or individuals who do not want to be tracked by their companies. Raytheon's Andy Proctor says examples of UK military facilities being inadvertently denied GPS service by passing motorists are not unknown.
GPS jamming equipment is clearly a threat to US, UK and NATO operations. Raytheon's latest anti-jammer devices have been miniaturised enough to be carried on any platform, and what Proctor describes as the "building blocks" of a future system to protect forces from navigation signal jamming are being developed. But, he stresses, the jammers have a relatively easy target; GPS signals are very weak, on the order of 25W, so can be overwhelmed locally by equipment built from cheap electronic components. Battery-powered jamming units scattered about an operational area could be hugely disruptive and very difficult to find and disable.
Raytheon's John Craib notes that jammers capable of operating over several kilometres are more expensive but available. But, he says, when units capable of jamming GPS signals - or those of other navigation services including Europe's soon-to-be-operational Galileo constellation - over a few thousand kilometres are available, the availability of satellite signals themselves will be in question.
At that point, says Craib, satellite makers will be looking to incorporate anti-jamming technology like that made by Raytheon. But denial of service, for example to prevent targeting, need only be achieved temporarily and locally.