The UK is following the USA's drive towards network-centric warfare with moves to link its Apaches into a digital communications system

Late in September, a British Army Air Corps (AAC) Westland Apache AH1 attack helicopter hovering on the edge of Salisbury Plain was hunting for tanks moving across the British Army's largest training area. A few minutes later officers in a command post on the North Yorkshire Moors, 320km (200 miles) to the north, were looking at the radar "target sweep" imagery downloaded from the Apache and transmitted to a laptop computer over a high-frequency radio link. The officers quickly generated a fire-control order and in minutes had sent it back to the helicopter.

High overhead "somewhere over the Midlands", on a Royal Air Force BAE Nimrod R1 electronic intelligence platform, an operator was monitoring a Joint Tactical Information Distribution System (JTIDS) Link 16 datalink display and picked up the Apaches. The operator was reportedly "very surprised" to see the helicopters because they do not normally have Link 16.

"The Project JENYSIS [Joint Effects Network Integration System] trial was a toe in the water of digitisation," says Col David Husband, deputy director equipment capability-air manoeuvre at the UK Ministry of Defence, who leads the Apache effort. "It was an advanced concept demonstration - a proof-of-principle exercise to see what could be done with existing equipment, with a small investment in high commercial-off-the-shelf [COTS] technology. The aim was to demonstrate the benefits of integration."

UK defence secretary Geoff Hoon this year announced the results of studies into the New Chapter of the Strategic Defence Review. His proposals were peppered with references to network-centric warfare or the linking of sensors to precision-guided weapons, via high-speed digital links.

For British Army officers and MoD procurement officials charged with translating this vision into reality in a cost-effective way, the UK's Apache programme has thrown into high relief the opportunities and challenges involved in fielding network-centric technology. The Apache programme has been the subject of recent criticism from the UK's National Audit Office, particularly concerning training and the operation of some systems (Flight International, 5-11 November).

The UK launched its £2.5 billion ($1.57 billion) Apache project in July 1995. A high off-the-shelf element was a key part of the procurement and the British Army bought its Apaches with ITT Industries Sincgars ARC-201D radios, standard fit for the US Army's AH-64Ds. That these radios could not transmit data into the British Army's planned digital Bowman radio network was not seen as a major problem. The programme to field Bowman was far from complete and other issues were more pressing.

When General Dynamics UK (GDUK) was selected as Bowman prime contractor last year, the issue of how the AAC's 67 Apaches would share digital data with the rest of the British Army rose up the agenda. How to share and fuse the data from the Apache's millimetric Longbow radar became a pressing issue.

One possible answer is the Improved Data Modem (IDM) with the protocols hosted on PCMCIA cards - the IDM is a standard AH-64D fit. It is a PCMCIA card-size modem that allows conventional radios to transmit compressed high-quality data using a pre-selected protocol. It is available in several configurations from at least four manufacturers.

"We had previously only considered the IDM as a way to communicate within the Apache fleet," says Husband. "Two years ago we discussed with Aerosystems International [AeI] future development of its Apache Mission Planning Station [MPS]. "This basically programs the Apache with a variety of mission-specific data, including a map overlay for multipurpose displays, in a format it understands. We asked AeI to demonstrate if it could do it the other way around and make the MPS part of the Bowman network."

Text messages

AeI proved the concept of linking an MPS on laptop PC via standard military radio to an Apache. The MPS was able to generate a present-position request from an airborne Apache and track its movement in real time, displaying the result as an icon on the MPS map. Free text messages could also be transmitted between the helicopter and ground station. "This gave a possible route to Apache data functionality ahead of Bowman," says Husband.

The IDM was attracting interest within the UK and US armed services in the late 1990s and it led to the launch of joint Project Extender trials. These linked fast attack aircraft with ground forward air controllers, via an IDM rebroadcast package mounted on a General Atomics RQ-1 Predator unmanned air vehicle. The UK Apache programme then piggybacked on to Phase 3 of the Extender trials to launch Project JENYSIS.

"We were interested in spreading sensor-to-shooter networks," says Husband. "We demonstrated a number of critical links. The first things we linked were an MPS on Salisbury Plain with 16 Air Assault Brigade's headquarters at Catterick. We were able to send files of different sizes. This demonstrated to 16 Brigade's commander a live picture of radar imagery of Salisbury Plain. We did this on HF radio and also UHF rebroadcast via Extender gateways on the ground and airborne in Qinetiq's [BAC] One-Eleven using IDM technology. A ground forward air controller then located a target, passed it to an Apache in the form of a digitised nine-line brief, which then relayed it to a [Sepecat] Jaguar, where it was passed directly into its weapon-aiming computer and it dropped live ordnance on the target. A nine-line brief can take up to two minutes using voice and authentication, but we did it in milliseconds. Perhaps most significant was the ability of the Extender payload to interface the IDM network with a Link 16 network," he says.

While current-generation IDM technology is a near-term answer to the Apache digitisation gap, the British Army is looking to improve links between its attack helicopter fleet and the wider Bowman network. The Apache computer architecture and software, particularly its moving-map system, cannot cope with full Bowman digitisation, so the Army is looking to a "gateway" solution using modified modems to allow data to flow across IDM and Bowman networks. GDUK, Innovative Concepts and AeI are offering a solution based on this concept as their Apache Bowman Connectivity (ABC) proposal.

The ABC ground stations will in effect be communication nodes or access units that use software to translate data so it can flow across networks. This will allow a wide range of ground forces headquarters to tap into the Apache's radar picture and other data. It will not, however, offer the full functionality of the ground Bowman network. This will have to wait for the Apache mid-life upgrade, due after 2012.

The MoD is expected to decide on ABC go-ahead by year-end. Final evaluation is under way, but senior programme managers say a decision "must" be made soon or a key opportunity to procure the modified Bowman radios for the access units will be missed. "If we don't do this now we won't be able to do it until 2008-09," says one source. Described as "affordable", ABC could be ready for 2005-06 when 3 Commando and 16 Air Assault brigades, the UK's rapid reaction units, are due to be "Bowmanised". This will coincide with the first Apache regiment being declared operational, if plans stay on schedule.

ABC savings

While the ABC saves huge amounts of money because aircraft do not need to be modified, it makes the UK Apache fleet dependent on ground-based gateways. "IDM networking does feed into GDUK-led ABC solution, but it is not quite the same thing," says Husband. "We are keeping the door open to both solutions. The problem is that 16 Brigade's task force may operate at ranges between 100km [55nm] and 200km ahead of our own troops. It will, in effect, outrun the Bowman network, even if Apache is fully Bowmanised. There is a requirement for beyond-line-of-sight communications. High-frequency radio, satcom and rebroadcast are all possible solutions. We need to find a system that is robust across all three domains."

Husband views links into the main JTIDS networks maintained by UK and allied air forces as particularly important. "This may be a way indirectly to pass the locations of attack helicopters to our air defence batteries, via gateways. Air defenders [who are all to have JTIDS datalinks] will already know a target is a friend without having to interrogate it [with IFF systems]."

The US origins of the UK Apache's communications equipment, however, means that for the near-term interoperability with US forces is achievable. Longer-term US digitisation efforts are being closely monitored by the UK. Future experiments being considered by the UK include loading the Extender IDM rebroadcast package into a battlefield helicopter, perhaps to carry a number of rebroadcast and data-conversion tasks.

"We hope to try to join up sensor to shooter networks using narrowband data pathways which may not be as capable as the full Bowman [system], and certainly not JTIDS/Link 16, but are as affordable and achievable in the near term," says Husband.

Use of experiments to prove digitisation technology is seen as the way forward and frontline units are more likely to find themselves involved in this process. Husband says: "It is easy to teach young people how to use a data communications systems if it looks like Microsoft Windows. It is no more difficult to understand than their home computer connected to the internet."

Source: Flight International