The Australian Defence Force (ADF) today signed two contracts worth $393 million to maintain its 'over the horizon' radar capability for the next five years.
The contracts have been awarded to two Australian companies and are expected to provide ongoing employment for more than 300 people.
More than half of these jobs will be located at the Edinburgh Defence Precinct, Adelaide.
The contract with RLM Pty Ltd, worth $262 million, will provide support for the two Jindalee Operational Radar Networks sites at Laverton in Western Australia and Longreach in Queensland.
The second contract with BAE Systems Australia is to the value of $131 million and provides for the support of the Jindalee Facility Alice Springs radar site.
Both contracts will also support the Over the Horizon Radar, Centre of Excellence and the Systems Program Office, in Adelaide, South Australia.
The new contracts will standardise engineering, logistics and maintenance support procedures across both contractors and the Commonwealth, and consolidate the maintenance of specialist transmitter and receiver equipment.
Additionally, the new contracts contain an acquisition development component which provides for the future capability development of the Over the Horizon Radar network.
Jindalee Operational Radar Network, or JORN, conducts 24-hour all weather detection of north and northwest air and surface approaches up to 2000 kilometres away from Australia's coastline.
JORN is an early warning trip-wire in the defence and protection of Australia and our national interests, able to detect surface vessels and low-flying aircraft.
JORN also assists Coastwatch, Customs and Immigration in the detection and prevention of illegal entry, smuggling and unlicensed fishing as well as helping with search and rescue efforts and early storm warnings.
The radar network can also detect stealth bombers and has taken more than 30 years to complete at a cost of $A1.8 billion.
JORN uses two high frequency radio transmitters located 2300 kilometres apart, at Longreach and Laverton. The transmitter arrays are about one kilometre long and can generate a 20 kilowatt signal, which is stronger than most radio station signals.
Signals are aimed at the ionosphere, where the beam is reflected over the horizon to targets up to 3000km away.
A weak return signal from over the horizon is captured by a highly sensitive receiver that uses advanced software to separate background "clutter" from selected targets.
The receivers consist of two "arms", each 3.4 kilometers long, and each site consists of 960 individual antenna masts that must not be more than 10mm out of line along the whole length.
Transmitter and receiver sites near Longreach and Laverton are located about 100km apart to prevent electronic interference.