Australia’s Jindalee Radar System Gets Performance Boost

The Jindalee over-the-horizon radars are substantially improved
Sep 22, 2014 Bradley Perrett | Aviation Week & Space Technology

Australia has to choose its defense technology programs carefully. While the country expects to field advanced armed forces, with a population of 24 million it lacks the money and depth of engineering expertise for much domestic development.

But for decades Australia has tirelessly pursued one particularly difficult program: Jindalee, an over-the-horizon radar system that answers the national problem of how to economically monitor the vast maritime approaches of a continent.

With little publicity, the defense department and its contractors have completed a major upgrade of Jindalee, whose three enormous antenna installations, ranged across the Outback, bounce high-frequency radio beams off the ionosphere to observe aircraft and ships at least 3,000 km (1,900 mi.) away, perhaps as far as the South China Sea. The upgrade has increased the speed, sensitivity and precision of the sensors, and knitted them into the national command and control system of the Royal Australian Air Force (RAAF).

The department plans to seek preliminary approval for further enhancements by June 2015, although the focus of development effort is now moving to ensuring that the RAAF can operate the system, formally known as the Jindalee Operational Radar Network, until around 2040.

Australia does not disclose much about Jindalee, usually describing little more than its operating principles. But in an interview with Aviation Week the department’s acquisition agency, the Defense Material Organization (DMO), has detailed the achievements of the latest upgrade and the aims of the next, while still withholding most numerical measures of performance.


The upgrade was Phase 5 of the Jindalee program, Joint Project 2025. Defense Minister David Johnston revealed completion of Phase 5 on May 28, saying it had reached final operational capability. That level was in fact attained late last year, says Air Commo. Mike Walkington of the DMO.

The upgrade was delivered two years late, partly because of a skills shortage, but achieved almost all the -specifications and came in under budget, says Walkington. The work was performed by the Australian operations of Lockheed Martin and BAE Systems, with support and advice from the Defense Science & Technology Organization. The budget has not been disclosed.

Thanks to Phase 5, the radars at Laverton, Western Australia, and Longreach, Queensland, have been bought up to the standard of the original installation in the center of the continent, at Alice Springs, Northern Territory. As a developmental system benefiting from constant tinkering, the Alice Springs radar was more advanced. Now they are the same and the Alice Springs radar is integrated as an operational installation. It no longer has a special status; any of the three can be used for further development work, says Walkington.

As is usual with major improvements to defense systems, Phase 5 relied on faster electronics. The arrays now collect much more data, which are sent in basically raw form to RAAF Edinburgh, a base near Adelaide, South Australia, where the radars are controlled. Bandwidth between the arrays and the base had to be greatly enlarged.

Edinburgh processes the raw information to extract track data that go to RAAF Williamtown at Newcastle, New South Wales. There it is fed into Vigilare, a Boeing command-and-control system that integrates tracks from various sources to create the national tactical air picture. Jindalee was linked to Vigilare before Phase 5 was completed. It is now “well integrated” with the command-and-control system, says Walkington.

The data going into Vigilare are also improved. Jindalee is now more sensitive, better able to extract targets from noise and to classify them by size. The system also determines their locations, and presumably speeds and headings, more precisely.

“We didn’t necessarily get a big improvement in the size of the target” that can be detected, says Walkington. Detectable target size has decreased, but the gain was nothing like an order of magnitude. The department is not changing its guidance that the system can detect targets as small as jet trainers or 300-ton patrol boats. The actual performance may be somewhat better, but the RAAF has long been adamant that these radars cannot detect, for example, a slow wooden boat, even one with the metal of its engine exposed.

Such sensors detect targets by Doppler, the slight shift in frequency of the reflected radio waves caused by a target’s motion toward or away from the radar. They are challenged not only by the vagaries of the ionosphere, which acts as a blurry, unstable mirror for bouncing the beam, but also by the colossal ranges at which they are operating: The returned energy from a target thousands of kilometers away is minuscule. The arrays are necessarily huge. The transmission array at Alice Springs is 2.8 km (1.7 mi.) long.


A key advance in Phase 5 is processing speed. Radars such as Jindalee do not smoothly sweep their fields of view but, rather, dwell on patches, called tiles. Following the upgrade, the three Jindalee installations “can look at larger tiles in less time,” says Walkington. He will not say whether the dwell time is tens of seconds, minutes or tens of minutes for each tile, but it is clear that faster radars can better scan large areas by shifting from tile to tile. Phase 5 has made Jindalee more digital but not fully so, says Walkington. Analog-to-digital conversion of the signal is not done immediately at the array. The antennas are phased arrays, so the beam is steered electronically in azimuth, but each radar can apparently dwell on only one tile at a time. Asked whether more than one could be observed simultaneously, Walkington says: “We have three radars.”

Solar flares and coronal mass ejections disrupt the ionosphere, and this remains a problem. But the radars can better handle changing ionosphere conditions. Altogether, Phase 5 implemented every intended improvement except one based on artificial intelligence.

Walkington will not specify Jindalee’s performance, except to say that the range of the system has not changed from a minimum of 1,000 km to a maximum of 3,000 km, the figures that the department and RAAF have previously stated. Australian defense analysts believe that under suitable ionospheric conditions it can see much farther.

There are signs that improvements in sensitivity and precision in Phase 5 have been considerable. One indication is that the department does not expect the next phase to achieve as much. Progress is increasingly difficult, although Walkington adds: “We will constantly work on detection accuracy. We will constantly work on monitoring the ionosphere,” a key issue in extracting sharper data.

Another sign of a hefty gain in performance is that the sensitivity has improved enough to meaningfully cut costs. Depending on the conditions, the radars now operate at reduced power, accounting for much of an expected saving of AUS$100 million ($93 million) over 10 years. Unsurprisingly, then, Phase 5 did not replace the high-frequency power amplifiers; the original output is clearly sufficient.

The RAAF does not operate Jindalee continuously, because of cost and the lack of a peacetime need to do so. But the low-power modes now available clearly raise the possibility of using the radars more often.

A few days after the disappearance of Malaysia Airlines Flight 370 early on the morning of March 8, Aviation Week asked whether Jindalee had tracked it. The chance was never high, because reflections from the ionosphere are weak at night, discouraging over-the-horizon radar operation then, and because the Boeing 777 would have had to have flown through a tile that a Jindalee radar had for some reason been cued to observe. The aircraft also would have needed to follow a course that created a detectable Doppler shift. Typifying its reluctance to discuss Jindalee, the department replied by saying it was passing any information it had to Malaysia; it did not refer to the over-the-horizon radars.

The Phase 5 upgrade followed the much-delayed delivery in 2003 of the operational Jindalee system, including the Laverton and Longreach installations. The first contractors for the operational systems, including the telecoms company Telstra, failed to deliver on time, so Canberra called in a joint venture that included Lockheed Martin.

So potentially valuable was the system that the government never seems to have considered giving up. Jindalee’s key advantage is that it allows Australia to better deploy its limited number of aircraft and ships, says Andrew Davies of the Australian Strategic Policy Institute. The system’s data are too imprecise for targeting, but it can cue other surveillance systems, such as the Boeing Wedgetail radar aircraft and Lockheed P-3 Orions. It is itself presumably cued by other data sources, including information from allies.

An important but unanswered question is whether Jindalee is precise enough to direct fighters relying on their own radars to find an air target; 24 years ago, very early in its development, it was far from being able to do so, a U.S. Air Force statement at the time suggested.

Over-the-horizon radars have the key advantage of defeating stealth. Igor Sutyagin, Russian studies fellow at Britain’s Royal United Services Institute, pointed to such capabilities of very-long-wave radars in a paper released this month. “Longer wavelength, decameter-band radars” such as the Russian Rezonans-NE could be effective against the Northrop Grumman B-2 and other targets designed to evade detection by very-high-frequency (meter-band) radars, Sutyagin says.

Jindalee operates in a similar band. According to one U.S. technical paper, at very long wavelengths that are close to the physical size of the target, conventional radar cross-section measurement and reduction techniques do not apply, and the target’s detectability is a matter of its physical size.

The just-completed upgrade of Jindalee got off to a slow start. About two years was lost at the beginning, leading to the two-year delay in delivery, largely because of the departure of people who had worked on building the operational system. This is emblematic of Australia’s challenges in developing advanced defense systems alone: It lacks a deep pool of skills. And, although various countries have built such radars since the 1950s, the Australians believe they are on the leading edge of the technology, so they cannot turn to allies, such as the U.S., for help.

The next upgrade, Phase 6, was also in danger of an exodus of essential workers. “As we were coming to the end of Phase 5 we could see the same thing happening,” says Walkington. So the department is implementing an interim effort, Phase 7, with the main objective of keeping 60 or so key people engaged.

Their tasks will include improving or developing radar performance-analysis tools, working on wave-form generator and receiver technology for Phase 6, developing multichannel digital receivers that will reduce component count, improving ionosphere sounders and developing software tools suitable for long-term sustainment.

Phase 6 will be aimed mainly at dealing with obsolescence. The department hopes to gain government approval in the first half of 2015 to begin soliciting contractor bids. Two years later it will seek approval to issue contracts, subject to intervening reviews of defense policy.

Apart from general performance improvements, Phase 6 will give operators the ability to vary tile sizes, which are currently fixed. Networking may be improved as well.

–With Bill Sweetman in Washington.

The RAAF does not operate Jindalee continuously, because of cost and the lack of a peacetime need to do so. But the low-power modes now available clearly raise the possibility of using the radars more often.