Jindalee Over-the-horizon Radar
Description
Jindalee is an Aboriginal word for a place [the] eye cannot see, or somewhere beyond where the eye can see, like over the horizon. The original project to develop an over-the-horizon radar in Australia was called Jindalee and the operational outcome of that project called JORN (Jindalee Operational Radar Network) continues the use of the iconic name Jindalee.
Over-the-horizon radar operated in the High Frequency frequency band, unlike conventional radars whivch operate in the microwave band. The signals are bounced off the underside of the ionosphere to the target and back by the same route. Powerful computers analyse the returned signals to provide useable data.
Australia has been a leader in the development of the technology and the JORN system, operated by the Royal Australian Air Force, with a coverage of over thirteen million square kilometres to the north and west of Australia is the most advanced such system now in operation. The radar receives returns from aircraft and ships in its target area.
The Defence Science and Technology Organisation carried out its first research into the system in the early 1950s. The Jindalee Projects (Stages A & B) from 1970 to 1982 demonstrated the success of the Australian technology and research continues to improve the system's performance. The ultimate range and performance of the radars are classified however publically available from the RAAF and otrher sources give an insight into a very powerful surveillance system.
The JORN network is operated by
No. 1 Remote Sensor Unit (1RSU). Data from the JORN sites is fed to the JORN Coordination Centre at
RAAF Base Edinburgh where it is passed on to other agencies and military units. Officially the system allows the
Australian Defence Force to observe air and sea activity north of Australia to distances up to 4000 km. This encompasses all of Java, Irian Jaya, Papua New Guinea and the Solomon Islands, and may include
Singapore. However, in 1997, the prototype was able to detect missile launches by
China over 5,500 kilometres (3,400 mi) away.
JORN is so sensitive it is able to track planes as small as a
Cessna 172 taking off and landing in East Timor 2600 km away.
The development of Jindalee was not subjected to much public scrutinay as the development was so successful, To this day few Australians are aware of the capabilities of JORN and its ever-vigilant surveillance of Australia's Northern Approaches.