One of the most powerful and versatile air-defense radars in the world (the Australian JORN or Jindalee Operational Radar Network) has completed another round of upgrades and has become fully operational. This is a network of two large radars in northern Australia (and a development radar in central Australia) whose data is combined at another air force base.
Australian scientists and engineers designed and built this unique, over the horizon, system using the technique of bouncing radar signals off the ionosphere. This gives the radar a range of over 3,000 kilometers. Development began in the early 1990s. Costing over a billion dollars to build, it became partially operational in 2002. Since then new capabilities were added while all the original capabilities were gradually brought online.
The key to the system is software that enables a weak return signal to be accurately identified. Thus, even stealth aircraft can be spotted by JRON. Many of the systems capabilities are kept secret, but the United States has been working with Australia to integrate JORN into a world-wide anti-ballistic missile defense system. Currently, JORN provides plenty of warning if hostile aircraft should approach Australia.
The system was designed to provide coverage for Australia's northern coast, which is largely uninhabited, but also vulnerable to smugglers, illegal migrants, or armed invaders. JORN can be reconfigured to search for ships as well, and has been used in this way to spot ships trying to bring in illegal migrants. JORN is operated by the Royal Australian Air Force.