A poor target hit rate over Kosovo is driving development of the RAF's intelligence, surveillance and target acquisition capabilities


Stewart Penney/LONDON

The findings of a UK Ministry of Defence report into the success rate of Royal Air Force bombing during Operation Allied Force against Yugoslavia last year is driving the development of the nation's intelligence, surveillance, target acquisition and reconnaissance (ISTAR) capability.

Revealed exclusively by Flight International (15-21 August), the classified report indicates that only 40% of the weapons dropped by Royal Air Force BAE Systems Harrier GR7s and Panavia Tornado GR1s in Allied Force can be confirmed as hitting their targets. Most of the remaining weapons cannot be accounted for because the impact point could not be seen, mainly due to heavy cloud cover.

The report's findings underpin ongoing concerns within the RAF and MoD that without accurate target acquisition data and the ability to discern targets in difficult operating conditions - as well as designate and destroy targets in all weathers - air power will remain hampered.

Explaining the report's findings, MoD and RAF officials said last week that ISTAR is a priority for the RAF.

Range of Assets

ISTAR - referred to by the MoD as ISR, intelligence, surveillance and reconnaissance - covers the collection of data on enemy targets. Assets deployed can range from tactical unmanned air vehicles (UAVs), operating close to the front line, to manned airborne assets such as tactical reconnaissance fast jets, electronic intelligence (ELINT) platforms and air-to-ground surveillance systems up to reconnaissance satellites.

Information retrieved ranges from the distribution of enemy forces and location of mobile targets to identification of key logistics points and the location of radar and air defence centres, and command and control points.

ISTAR also permits battle, or bomb, damage assessment (BDA), the evaluation of the success of an attack. Use of pre- and post-strike data can aid the determination of where weapons fell.

Around 30% of the weapons used in Allied Force by the UK could not be accounted for using the recording systems on board the strike aircraft, the report reveals. But with the greater use of standoff weapons, such as the Matra BAe Dynamics Storm Shadow, and lock-on-after-launch munitions, such as the Alenia Marconi Systems Brimstone, the need for more sophisticated BDA will increase.

The UK Defence Evaluation and Research Agency (DERA) has been studying a better match between ISTAR capabilities and weapons and other systems.

Use of synthetic aperture radar (SAR), which generates high resolution images and is unaffected by weather, is being scrutinised as a means of giving commanders improved information.

Several UK programmes will lead to the fielding of SAR systems. The Raytheon Airborne Standoff Radar (ASTOR) air-to-ground surveillance radar system will have a SAR mode as well as a moving target indicator capability. When it enters service in late 2005,ASTOR will be one leg of a triumvirate of ISTAR assets based at RAF Waddington in Lincolnshire. The other elements will be the ELINT-dedicated BAE Systems Nimrod R1 and the Boeing E-3D Sentry AEW1 airborne warning and control systems (AWACS).

An invitation to tender for the so-called Pod SAR programme should be released next month to BAE Systems, Israel's Elta and Thomson Racal Defence. Pod SAR will provide fast jets with a tactical, but standoff, SAR capability to support traditional tactical reconnaissance capabilities.

W Vinten, the UK reconnaissance equipment specialist, is also improving the capabilities of the low-level reconnaissance pods, while Raytheon is due to deliver shortly the Raptor pod for medium to high altitude missions.


The Watchkeeper UAV programme - which combines the Sender and Spectator projects that started as part of the UK/US Tracer future combat vehicle requirement - is likely to be equipped with a SAR as part of its sensor suite. Watchkeeper's size, shape and full capabilities are yet to be determined, with teams led by BAE, Lockheed Martin UK Government Systems, Northrop Grumman and Racal about to begin one-year study programmes.


Sender and Spectator had a planned in-service date of 2008, but Watchkeeper should be fielded in 2006. Industry observers suggest that the demise of US funding for Tracer could mean Watchkeeper will enter service with more capabilities than army-only ISTAR, becoming a larger UAV capable of target designation and equipped with systems to shorten the sensor-to-shooter, and potentially the sensor-to-weapon link. One industry source suggests that the RAF will try to accelerate the programme once the link to Tracer is broken.

Range of Capabilities

An MoD source says, however, that SAR is not the "whole story", for BDA or ISTAR. "It should be part of a range of capabilities", likely to encompass ASTOR, ELINT, electronic support measures (ESM), overhead reconnaissance, signals intelligence and tactical reconnaissance. SAR cannot distinguish the extent of damage to bunkers or small amounts of damage - as smart weapons develop, warhead sizes will diminish in size, making post-strike analysis more difficult.

A significant level of international attention has been focused on improving sensor-to-shooter links following the Kosovo action. The time from an ISTAR asset detecting a target to the start of an attack needs to be reduced, particularly for mobile targets. Allowing the sensor to pass GPS satellite navigation data directly to a weapon - so-called sensor-to-weapon capability - will further reduce reaction times.

Towards the end of the Kosovo campaign, the USA used a General Atomics RQ-1A Predator UAV to designate a target for a laser guided bomb (LGB), although an attack did not take place because of problems with the manned aircraft. Later this year the USAF will drop weapons from an RQ-1A while the company plans to fly a turboprop-powered Predator later this year which will have a greater capability to carry weapons and additional sensors.

A larger UAV could designate a target for LGBs with embedded GPSsatellite navigation in areas affected by cloud cover. A manned aircraft would drop the weapon using GPS through the cloud. The LGB would be steered initially using GPS but would pop out into the laser "basket" created by the UAV, flying beneath the cloud, and use the laser guidance to steer towards the target. If the bomb missed the basket, it would be guided onto the target using GPS.

The combination of laser and satellite guidance provides a back-up which can be useful when the weather over the target is unsuitable for visual guidance, although the GPS-guided weapon does not have the same accuracy as the LGB. The UAVwould also record the impact and damage for BDA.

Improved BDA will also eliminate the need to revisit some targets to ensure the job has been done. One of the earliest lessons of air warfare is that not returning to a target reduces the likelihood of being shot down - important when political necessities require a zero casualty rate.

Improving BDA

Improving BDA will undoubtedly reduce the number of unaccounted-for weapons. This is particularly true for environments faced in Yugoslavia in April-June last year which had 50% or greater cloud cover for more than 70% of the time, says a senior defence source.

Cloud cover affects the use of LGBs that have to be tracked and guided all the way to the target by the BAE Systems TIALD pod. The MoD report reveals that 65% of the 454kg (1,000lb) Paveway IIs dropped hit the target, with the others declared as misses. It is believed that some of the latter fell outside the small area for classification as a hit, yet may still have struck the target. There is also a problem when launching two LGBs at the same target in that the fall of the second bomb is obscured by the impact/explosion of the first.

Before Kosovo, a senior defence source says, the RAF had dropped limited numbers of the larger 905kg (2,000lb) Paveway III: "Paveway II, we're pretty familiar with. Paveway III is relatively new." The initial operational use was from Tornados over Iraq in 1998, but the Harrier had little experience with the weapon and a now-rectified integration problem meant that the weapon was not dropped successfully.

Success Rate

The source accounts for the difference between the 85% Paveway II/TIALD success rate during Operation Deliberate Force (over Bosnia in 1995), as a difference in the type of operation and the luxury of selecting which days to operate. He says Deliberate Force was "coercive" and the drops were made on only 12 days of the operation's 22 and the air defence environment was less heated.

The high number of unaccounted-for weapons is understandable as most unguided weapons drops were through cloud and the impact of the bomb could not be recorded. Attacking unseen targets calls for a high level of skill by the crew - which take the final decision whether or not to proceed with the attack - when politicians demand minimum collateral damage.

The senior source says: "The ideal is to drop PGMs [Precision Guided Munitions] as it reduces risk to a minimum. Because of the weather there were large periods of time when we couldn't drop [PGMs], but we had to maintain the operational tempo. The USAF had GPS-guided weapons and we said 'can we drop unguided bombs with confidence against suitable targets'." Such targets were large area targets where the potential collateral damage risk was regarded as minimal. In some cases risk was reduced, he says, by dictating which approach to the target should be taken to avoid dropping weapons towards sensitive areas.

The capability has been developed because of the sophistication of the bomb aiming system in the Harrier and the use of engineering tools such as computational fluid dynamics to improve the understanding of a weapon's ballistics. Although the circular area of probability - the measure of accuracy - will not be as good as LGBs or GPS guided weapons, it will be suitable for large area targets such as encamped troops, and ammunition dumps. "We know it is not pinpoint accuracy and that it is of little use against bridges," says the official.

The likelihood, says the source, is that many of the unaccounted for weapons landed within the target area, because when NATO advanced into the disputed territory "there were not many craters all over Kosovo".

Much criticism has been levelled at the MoD by the UK National Audit Office and various key House of Commons committees on the delay in replacing the unguided RBL755 anti-armour cluster bomb. If the RBL755's replacement - Brimstone - had been available, the number of successful strikes may have been higher. But, Brimstone's lock-on-after-launch operating mode and autonomous target selection would have made it equally difficult in poor weather to determine where the missile went once launched. The lock-on-before-launch Raytheon AGM-65G Maverick, ordered for the Harrier as a result of Allied Force, uses an infrared seeker and is regarded as a line-of-sight weapon requiring reasonable weather although it does provide a standoff and "turn away" ability, eliminating the need to overfly the target which is required to drop an RBL755.

Key Lessons

The report also says six Matra BAe Dynamics Alarm anti-radiation missile were fired but all were unaccounted for, although it is generally accepted that if an air defence radar is switched off after launch of an anti-radiation missile, it has been successful. This underlines the need for better BDA capabilities with stand-off weapons. While SAR would be of limited use to establish whether a radar site was "permanently off-air", other ISTAR assets such as ELINT and ESM would be suitable.

The UK MoD has already identified ISR/ISTAR as a key lesson of the Kosovo campaign. It has already actioned other lessons, acquiring new weapons and secure communications. Now it is time to seriously develop ISTAR.

Source: Flight International