The Jindalee over-the-horizon radar network has now achieved final operational capability after a technology upgrade.

We don’t know much about the Jindalee radar network – because it’s top secret – but we now know that whatever it does it’s doing it better.

The over-the-horizon system, developed from uniquely Australian research, has now achieved final operational capability after a technology update.

The Jindalee project was launched in 1974, with the system officially switched on in 2003 after long delays and technical problems.

It gives Defence the ability to monitor a vast area of Australia and its northern approaches as far as Indonesia.

It can observe air and surface targets in an arc from Geraldton to Cairns with stations at Longreach (Queensland) and Laverton (Western Australia) and a control centre in South Australia.

It can detect aircraft and vessels 3000 kilometres away.

Under good conditions it can see much further but full details remain top secret.

It can certainly detect missile launches but its performance against wooden asylum seeker boats is unclear.

Jindalee operates by bouncing radio signals off the atmospheric layer known as the ionosphere, to follow the earth’s curvature.

It provides a far greater range than conventional line-of-sight radar.

Defence Minister David Johnston also announced the RAAF’s joint air-to-surface stand-off missile had achieved final operational capability.

The US-made missile can be launched from RAAF Hornet and Super Hornet aircraft to hit targets 300km away.

It can also be launched from the new jet fighters Australia is planning to acquire.