Australian SSR Capability Due For Upgrade

The recent announcement of the teaming follows completion and handover of Australia’s first Cossor monopulse secondary surveillance radar (SSR) at Brisbane’s new airport. Cossor is one of the UK’s leading suppliers of ATC systems and the advanced monopulse SSR system being offered for the RASPP programme has now been sold in nine countries. In the UK, Cossor’s monopulse SSR is being installed by both the CAA at 22 sites in addition to being standard fit at all Royal Navy and RAF airfields. Additionally, forty one systems have been contracted for installation across Canada, many of which are in very remote and environmentally severe locations, while the system is also in use in Saudi Arabia, China, Greece, Dubai, Bahrain and Switzerland.

Secondary Surveillance Radar is rapidly becoming the most essential element in overall ATC control. SSR operates differently though from Primary Radar, which, located at airfields and strategic points, merely transmits a radar pulse and records its return on a screen. No other information is available on the target other than its apparent relative bearing and speed estimate. Furthermore, Primary Radar is range-limited and subject to environmental problems such as clutter and can also be affected adversely by terrain, etc. Basically, it is used in terminal control areas with a range of between 50nm and 80nm being the order of the day.

Secondary Surveillance Radar, on the other hand, actually sends out a pulse (a single or ‘monopulse’ in the case of Cossor’s equipment) that interrogates the aircraft’s transponder unit. The transponder is encoded with specific data which is then bounced back from the aircraft to the ATC screens and effectively reveals the aircraft coding (identity), its heading, speed and altitude. Previously ATC had to rely purely upon pilot altitude call backs to obtain vital altitude data. In a busy control zone with dozens of aircraft within a confined area, some of which are in multi-layered holding orbits, it is imperative to have accurate and real-time hard data on the height of each aircraft in the stack. SSA thus has become the de facto king of airways radar monitoring and with the RASPP programme, its widespread introduction into Australia will no doubt greatly improve ATC procedures and operational efficiency.

In addition to bidding for RASPP, the Hawker Pacific/AWA/ Cossor combine will also be promoting its capabilities throughout the SE Asian and Pacific region. The group have already had favourable feedback from their October Beijing airshow presence and consequently hope to be able to have a comprehensive system operational in China before the end of the decade.

A definitive Request For Tender (RFT) for RASPP is due to be released this February with a purchase decision hoped for by year end. It is then envisaged that the first of the new units will become operational at Cairns during late 1989 with the total package of 11 SSRs and 6 new primary control radars (located at all the capital cities except Hobart) fully integrated by 1993.