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By Adam Baddeley, Deputy Editor, BATTLESPACE

The Air Mobile Recognised Air Picture programme (AM-RAP) is a rack mounted, transit case portable version of the Ground Recognised Air Picture (G-RAP) and one of a number of procurements that has come directly out of experience in the Gulf that is boosting the UK network Enabled Capability (NEC). Rockwell Collins UK is responsible for both systems which enhance the UK air defence capabilities as a precursor to the Land Environment Air picture Provision programme due later this decade.

Both G-RAP and the subsequent AM-RAP are data forwarding systems, designed to receive the air situational awareness picture feed from airborne Link 16 terminals such as the Royal Air Force’s (RAF) E-3D Sentry. The information is received on the ground via a URC-138 terminal in the ground and then transmitting that using HF and now VHF links to Rapier and High Velocity Missile air defence units tagging each track in detail and allowing users to interrogate the information regarding each, Resolution is better than one mile. Information can be received and displayed at the same resolution as the Link 16 picture which can have an accuracy of better than 50ft.

GRAP deployed successfully to Operation Telic in 2003, explained Stuart McCullouch, Business Development Manager for Tactical Data links at Rockwell Collins UK. “GRAP saw good service in the Gulf and was very popular with the troops. A number of lessons learned came out of the conflict and it has become part of NEC. We are quite pleased that we are on the ground floor of NEC as we move forward.”

Designed to provide the air picture to air defence assets G-RAPs role has now expanded and is beginning to be used in new ways McCullouch explained.
“The users found that it wasn’t just useful for air defence but it could also be used for offensive forces, giving them more freedom to operate by providing enhanced situational awareness – knowing when they are likely to be attacked by enemy air assets for example.”

The G-RAP is based on a RB44 truck, too heavy to be airlifted and inappropriate to light forces, particularly 16 Air Assault brigade who arguably had greater need for the air picture, not least to better monitor their own organic helicopter fleet in flight, providing they can be seen by a Link 16 platform for instance. To provide this capability, the transit case based AM-RAP was delivered in December 2003 under a follow on contract although it has not yet seen operational service.

The AM – RAP capability consists of a single URC-138 equipped JTIDS Link Crate (JLC) –known as the JTIDS Link Vehicle in the G-RAP – a seven two man portable, 44Kg transit case configuration in which the URC-138 SHAR link 16 terminal is placed. The JLC then transmits the air picture over its own bespoke VHF and HF links to the three AM-RAP Distributed Situation Awareness Picture (DSAP) stations. Three DSAPs were delivered with the systems; there is no specific limit on the number of DSAPs that are used. GRAP and AMRAP DSAPs are compatible and as such training has been conducted with more than 3 DSAPs.

These consist of a receive station and rugged computer screen and power supply in a four transit case load. Each DSAP has a crew of four allowing two-on-two-off shifts although a single soldier can operate the system if necessary. Unlike the RAP troop in which the Army predominates, the AM-RAP troop is exclusively RAF personnel. To cope with the vibration regime of deployment by helicopter further ruggedisation has been necessary.

While the G-RAP Troop deploys across the Army the AM-RAP is closely tied with the 16 Brigade although it is envisaged that it could be used to support 3 Commando or the UK’s third and newly formed 19 Light Brigade.

Communication in the G-RAP is provided using a Micom 2RS HF radio using a fan tail aerial for transmission using Near Vertical Incidence Skywave signal. The requirement is

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