US Air Force to bomb NT, test JORN radar
Monday July 24th 2006, 11:44 am

30mm depleted uranium bullet (image: to journalist Brendan Nicholson in The Age, the US Air Force is scheduled to practise bombing on a gunnery range in the Northern Territory, using B-1 and B-2 stealth bombers and B-52 heavy bomber aircraft. The Jindalee over-the-horizon radar system (Jindalee Operational Radar Network or JORN) is also to be tested during the exercise to see how well it performs detecting steath bomber aircraft.

Unfortunately, Nicholson fails to ask some important questions about this cooperative military exercise.

* Will the USAF be testing munitions containing depleted uranium (DU)? If so, how will they clean up the radioactive debris?

* Nicholson writes, “This week’s exercise will also give Australia the opportunity to see how effectively its revolutionary Jindalee over-the-horizon radar (JORN) system picks up stealth aircraft.” JORN has been known for some time to be flawed and massively over-budget. There was a big scandal in the media about this some years ago. Why did Nicholson refer to the radar system as “revolutionary” without questioning the known problems with JORN?

      Normal radar systems operate at UHF through to microwave frequencies. Radio signals above about 30MHz pass directly through the ionosphere into space, limiting the range of conventional radar to line-of-sight to the horizon. JORN relies upon lower frequency signals which, under certain conditions, can bounce off of the ionosphere to detect objects beyond the horizon. Typical Jindalee radar antenna array (image: are tuned to the frequency of operation by way of the length of the conductive elements in the antenna. The lower the frequency, the bigger the antenna. The massive JORN system installations, some with curtain-array antennas up to 10 kilometres long, are visible from space in Google Maps satellite photos here, here, here, here, here and here.

      Despite having some of the largest antennas ever constructed, JORN goes blind at certain times of day, particularly in pre-dawn hours. This insensitivity is most likely related to normal changes in radio wave reflectivity characteristics in the ionosphere, which occur every day. The ionosphere is more or less reflective of radio signals depending upon whether it is exposed to solar radiation at the time. At night, longer wavelengths repeatedly bounce off the ionosphere and back to the surface of the earth, travelling thousands of kilometres before the signals diminish in strength below the level of usability. In the daytime, long waves travel straight through the ionosphere into space. This is why you can often hear distant stations on AM broadcast radio late at night but not during the daytime. If JORN has blindness problems just before sunrise, most likely to the east of the radar, it will also have problems seeing to the west just after sunset.

      JORN was the subject of a Channel Nine Sunday story on huge military cost overruns back in 1997. The project was awarded to the UK’s GEC Marconi and Telstra, depsite the fact that neither Marconi nor Telstra had any expertise in over-the-horizon radar systems. Telstra is reported to have written down up to $1.2 billion in losses related to their participation in the project.

      The US military uses depleted uranium (DU) both in armour plating in tanks and in armour-piercing munitions due to the extreme hardness and density of the material. The World Health Orgaisation describes the hazards of human exposure to DU, particularly in cases where the material has been fragmented or pulverised, as might happen in discharge of DU munitions or in a crash of an aircraft carrying the material. Inhalation of radioactive dust (from any source) can cause a much higher than normal incidence of lung cancers in particular. The ‘Poison DUst‘ project describes these hazards as well as contamination of Iraqi cities which have come under fire by the US military. See also the Campaign Against Depleted Uranium (CADU).

      The Australian Defence Forces should be more forthcoming about effects on public health related to the use of DU in live-fire military exercises in Australia. A bit of realism from the Defence Department regarding the billions dumped into the flawed JORN system would be nice, too. Not going to hold my breath while I’m waiting for such clarity from the Government, but journalists at least should be poking them with some harder questions on these topics.


      4 Comments so far
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      Since publishing this item, I’ve spoken to a person who works for the Australian Government about JORN and how it is employed.

      JORN is apparently best suited for detection of ships, not missiles or aircraft. The blindness problems are not as crucial when detecting slow moving objects.

      JORN is used for initial detection of unauthorised vessels in and near Australian territorial waters. Ships are then pinpointed by long-range P3 Orion aircraft and then may be intercepted by ANZAC-class frigates, which can carry Sea Sprite helicopters.

      Comment by weez 07.28.06 @ 11:14 am

      “Will the USAF be testing munitions containing depleted uranium (DU)? If so, how will they clean up the radioactive debris?”

      Well if the USAF is only using bombers in NT depleted uranium use is very unlikely.

      Airborne depleted uranuim is mainly (perhaps only?) used for the cannon of ground attack aircraft. In the US armoury this is principally the A-10 “Warthog” which has a huge 30mm cannon.


      Comment by Pete 07.31.06 @ 12:07 pm

      when is this proposed bombing planned for?
      why is john howard allowing this?

      Comment by rae 08.04.06 @ 12:51 pm

      Pete, thanks for the detail.

      rae, the exercise should already have been completed. According to the story in The Age, it was to have taken place in the last week of July.

      I’m not sure what you mean by your query, ‘why is John Howard allowing this’? He’s almost sure to have invited them.

      Comment by weez 08.04.06 @ 2:47 pm

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