Information I had years ago from friends in the RAAF was that it was "bloody amazing" to quote them directly. Yes it works....
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Operation and uses[edit]
The JORN network is operated by No. 1 Radar Surveillance Unit RAAF (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 all air and sea activity north of Australia to distances of 3000 km. This encompasses all of Java, Irian Jaya, Papua New Guinea and the Solomon Islands, and halfway across the Indian Ocean. Other sources put the range at 4000 km from the Australian coastline,[17] as far away as Singapore[18]
The 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. Current research is anticipated to increase its sensitivity by a factor of ten beyond this level. It is also reportedly able to detect stealth aircraft, as typically these are designed only to avoid detection by microwave radar.[4] Project DUNDEE[19] was a cooperative research project, with American missile defence research, into using JORN to detect missiles.[20] The JORN is anticipated to play a role in future Missile Defense Agency initiatives, detecting and tracking missile launches in Asia.[21]