JORN: a world leading OTHR capability - Australian Defence Magazine

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JORN: a world leading OTHR capability - Australian Defence Magazine

By Julian Kerr | Sydney | 23 June 2018

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With antecedents stretching back to the UK’s Chain Home radar system of WWII, Australia’s world-leading Jindalee Over-The-Horizon Radar Network (JORN) is embarking on a major upgrade to combat future threats, including those likely to be posed by hypersonic missiles.

This is being carried out under Project Air 2025 Phase 6, a $1.2 billion undertaking for which BAE Systems Australia (BAES) was named preferred tenderer in March, beating off competition from Lockheed Martin Australia. Phase 6 includes a separate 10-year support contract.

Both companies have had lengthy associations with JORN. Lockheed Martin in association with then-partner Tenix successfully resuscitated JORN construction and in April 2003 delivered the operational system to the Commonwealth. Lockheed Martin subsequently managed and supported Radar One at Longreach in Queensland and Radar Two at Laverton in Western Australia.
For its part, BAES was involved in the development of high frequency (HF) radar and associated software for JORN initially through its acquisition in 1996 of AWA Defence Industries, and subsequently through legacy company GEC-Marconi. This company’s ill-fated joint venture with then-JORN systems integrator Telstra ran into technical problems and was supplanted in 1997 by the Lockheed Martin-Tenix partnership.

BAES has also managed the original Jindalee Radar 3 near Alice Springs primarily as a Defence Science and Technology Group (DSTG) testbed for JORN’s long-range detection capability. Until it was fully integrated into the JORN network in 2012, Radar 3 also acted as a separate operational radar when required.

Work under Phase 6 implementing the handover of support activities from Lockheed Martin officially began on 4 April, drawing on a 280-strong workforce that will grow later in the year.

BAES will assume full responsibility in September for the JORN Joint Coordination Centre (JCC) at RAAF Edinburgh (work previously shared with Lockheed Martin); for Radar One in October; for Radar Two in November; and for remote ionosphere sounders and transponders in December.

BAES is teaming with RCR Infrastructure, part of RCR Tomlinson, which is providing remote site facilities management. Other partners include Daronmont Technologies who will upgrade the sounders and transponders and assist with several builds of upgraded software at the JCC, and Raytheon who will provide systems engineering expertise and niche software skills.

Steve Wynd, the company’s JORN Program Director, says the transition is being handled by tripartite working parties from BAES, Lockheed Martin, and the Commonwealth.

Wynd praises Lockheed Martin site staff as dedicated and highly-skilled.

“Quite a number will come across supplemented by some of our people; they’re passionate about the capability and we’re keen to retain that capability and the investment that has been made by the Commonwealth in developing that over the years,” he commented to ADM.

Wynd anticipates increasing automation within JORN and installing additional performance measurement diagnostics to enhance the ability of JCC operators to undertake more maintenance and diagnostic functions remotely; the long-term objective being to reduce manning levels at all three sites.

At present Lockheed Martin operates Radars One and Two with two fly-in fly-out rotations of about 20 staff for the Transmit and Receive facilities at each site.

BAES intends introducing a common operating model for all three radars to facilitate the movement of personnel between sites and maximise efficiency, particularly when a radar is offline for maintenance or upgrading, Wynd says.

Although JORN operational support contracts are understood to specify 98 per cent availability and the ability for each of the three radars to operate 24/7, the system’s overlapping coverage means an individual radar can be taken offline for maintenance, research and development, and upgrade without disrupting surveillance. The system does not usually operate on a 24-hour basis.

Instead, the operating schedule is advised by the JCC at the request of Air Force through 41 Wing at RAAF Williamstown. Transmit is turned on first at each site followed by Receive, a process that with fault-checking, atmospheric analysis and determining what transmit channels are available (JORN is always a secondary user of the HF spectrum) takes about two hours.

The JCC then takes over operation of the system and 41 Wing decides on areas of interest (each of which is referred to as a ‘tile’) on which the system will focus (referred to as a ‘dwell’).

As set out in a 1987 technical specification, the system is configured to detect and track either aircraft the same size or larger than the RAAF’s Hawk Lead-in Fighter Trainer, or maritime vessels the same size or larger than the RAN’s long-decommissioned 41-metre, 220 tonne Fremantle-class patrol boats – so long as they have a metal hull or a metal structure encased in wood. It is not possible to search for both air and maritime targets at the same time.

Officially JORN allows the ADF to monitor air and sea activity north of Australia up to 3,000 km from a radar site. This takes in parts of Java, all of Papua New Guinea, and halfway across the Indian Ocean.

It would be an unusual defence establishment that was upfront about the performance of a strategic asset such as JORN, and anecdotal evidence suggests a range of at least 4,000 km from the Australian coastline depending on atmospheric conditions, with some capability as far north as the Korean peninsula.

Phase 6 upgrade scope
Project Air 2025 Phase 6 is in essence a mid-life upgrade that will move JORN into a new era with digital waveform transmitters and digital receivers, enhanced frequency management, communications and information systems, and better supportability.

As summarised by Dr Gordon Frazer, DST’s Research Leader High Frequency Radar, the project will enable the system to do more things at the same time. It will also significantly advance JORN’s ability to detect – although not necessarily to identify – targets in more difficult ionospheric conditions.

The system currently provides target type, speed, heading and position accurate at best to about 7.5km (at worst about 75km) but not target height which is furnished by other more precise sensors, when available.

Planning for the Phase 6 upgrade and maintaining what Dr Frazer categorically affirms is Australia’s global lead in OTHR technology began in 2012 on completion of the rolling improvements delivered by Project Air 2025 Phase 5, which incorporated the so-called Jindalee Facility Alice Springs (FAS) integration upgrade.

This created a common user interface across the Queensland and WA radars and the more advanced capabilities of the Alice Springs facility, which was integrated into the overall JORN network.

These advances and enhancements to the radars’ sensitivity have enabled JORN to surveil a specific area over a larger geographical region and move more quickly from one area of interest to another. Additionally, new signal processing algorithms have improved detection performance.

Following two years of extensive Phase 5 verification activities, JORN was declared fully operational in 2014 for the first time in its 25-year history amid wide-ranging discussion on the next stage of its development.

Dr Frazer says he had long made the point that a project scheduled to take five or six years was doomed to failure from Day One if it took four years to teach the workforce what to do.

“That was the experience we went through with Telstra/Marconi; they had no prior experience, they simply didn’t know enough about the business to do it and six years later they were selling out to Lockheed Martin/Tenix with a $600 million loss,” he commented to ADM. “When somebody joins my group in DST it takes them three or four years to have enough knowledge of the OTH radar and become useful in terms of thinking and acting independently – and that is post-PhD.

“We knew we had a few years after Phase 5 to do some things in advance to ensure that when the Phase 6 contract was ultimately signed the project would emerge as a success rather than another drama,” Dr Frazer said.

“Clearly there would be a gap during which we would lose the industrial workforce, so we proposed a program of work under the Priority Industry Capability program for designated sectors of strategic sovereign importance.

“We initially called that JORN Phase 7, since Phase 6 had already been agreed. A decision was subsequently taken to convert the requested funding from major project status to a sustainment-type arrangement and the Phase 7 title was then changed to the JORN Priority Industry Capability Support Program (JPSP).

“Our objective was to deliver all the technical solutions, with minimal technical risk, to the competing contractors prior to them bidding for the contract. Some of those solutions were very demanding. And although my group would not be constructing the radars, we’ve had enormous experience in building lots of stuff and we had somehow to impart that knowledge to the new workforce,” Dr Frazer explained.

This was achieved by targeting younger individuals in both companies in order to establish experienced leadership cadres, one of which in several years’ time would be instrumental in implementing the successful tender.

The idea of selecting a single contractor from a tender process restricted to BAES and Lockheed Martin was first raised within Air Force as part of strategic reform discussions, and was agreed after the completion of Phase 5.

“So the acquisition strategy was 90 per cent-10 per cent; roughly 90 per cent of the money goes to one contractor to do 100 per cent of the work and 10 per cent of the money goes to the second contractor as an engineering support contract to help the Commonwealth test and verify some performance obligations, and to pursue activities beyond Phase 6,” Dr Frazer outlined.

Understandably, the mass of technical material released to both companies as part of the JPSP and after first pass approval late in 2015 necessitated a comprehensive probity management plan to ensure each contender received identical information.
This data flow had a specific purpose – to ensure the existence of an educated workforce prior to tender, and to reduce major risks prior to tender through significant engagement with both companies in developing specifications.

“We had enormous numbers of meetings where we’d put forward a specification for a particular area to each contractor independently; they’d go away and say this is what we think you’ve asked for, we’d say no, this isn’t what we want at all,” Dr Frazer said.

“So there was this great sophistication in both contractors when they received the tender because they’d seen it before and had been able to critique it. We were focused on getting what we wanted, not what we might have asked for.”

Tender testing
Testing the practical ability of the contenders to fulfil Phase 6 requirements, and providing valuable experience along the way, revolved during the JPSP around the so-called ‘Big Four’.

These required each contender to construct a radar concept demonstrator, albeit a small one, successfully integrate it with examples of the proposed receive and transmit systems, and demonstrate that their concept could scale.

“Both contenders therefore had a sophisticated workforce underpinning their tender response, a really clear understanding of what the specification was, full knowledge that all the major risks had been dealt with, and that the competitor knew exactly the same,” Dr Frazer said. “So they were able to price their risks accordingly, and I think the Commonwealth got very good value for money in both the tender responses.”

Fundamental to the Phase 6 improvements – and as such to JORN’s ongoing capabilities through to the 2040s – are the digital receivers and transmitters developed by DST with assistance from BAES, and for which DST assumed the technical risk.

Depending on the target sector and atmospheric conditions, JORN radars operate somewhere between 5-32 MHz, transmitting a very powerful signal whose faint return over several thousand kilometres in a busy bandwidth restricted the capability of receivers to one radar function at a time.

“We’ve spent a decade developing a receiver with the technical performance to receive very weak signals in the presence of other very strong signals and do many things at the same time, and that’s a game changer,” Dr Frazer said to ADM.

“It’s specifically built around the challenge of common aperture in achieving the ability to see the whole HF band at once, and to do so with a satisfactory level of performance.

“Nobody in the Western world is close to it, we have a massive lead. We don’t get to see other countries’ receivers but looking at their transmitted signals I think they’re still behind.”

By implication this includes China’s Xiangfan skywave OTH radar in Hubei province, and Russian Kontainer system OTHRs looking into Western Europe.

World leading tech
Experiments undertaken with the Longreach and Alice Springs radars since 2012 helped prove the performance of the new digital transmit and receiver chains while new software concepts were prototyped through the radar concept demonstrators.

“The digital receiver substantially enhances the performance of the radar, as does the digital waveform generator,” BAES’ Wynd said to ADM. “We digitally construct those waveforms and then pump them out through high-powered amplifiers to create the signals that will go out to the target and reflect back.

“The common aperture receiver gives more opportunity to operate things concurrently, you can take a lot more data in and that improves the performance and the coverage of the radar.”

This attribute particularly enhances frequency management, which uses small arrays separate from the main radar to garner information on ionospheric conditions. JORN operators then use this information to determine how best to configure the main radar.

“Common aperture means we can do all of those functions on the main radar at the same time, you can automate part of that and also run the radar better,” DST’s Dr Frazer explained.

A further benefit will be the ability for each of the three radars to operate in different configurations and combinations.

“Instead of using the transmitter array and all the power for one mission at a time you can split each radar into half-radar mode which can then perform two missions at the same time,” Dr Frazer said. “Currently you’re forced to divide the receiving array as well, so a lot of sensitivity is lost and it’s not a mode the operators particularly want to use. With common aperture you don’t have to divide up the receiving array, it can run multiple radar functions at the same time.”

The importance of this digital capability is reinforced by statistics. Radar One at Longreach, a 90deg coverage radar, at its Transmit site has 28 drive chains each comprising a digital waveform generator, a high-power amplifier, and an antenna element within the transmit array.

Radar Two at Laverton doubles this since it has two faces giving 180deg coverage, although there is some multi-use of equipment. Radar Three at Alice Springs, also providing 90deg coverage, has 16 drive chains rather than 28 which reflects its earlier vintage.

For Receive, Radar One has 480 digital receivers – one per bipole antenna in the receiving array; Radar Two has 960 receivers, and Radar Three has 462.

Achieving a 20dB, 100-fold increase in sensitivity was a self-imposed technology challenge; Phase 6 will achieve a 10-fold increase in performance although an expensive technological solution for the higher end figure is available if it’s ever required.

Timeline
Upgrade activities started in April with the JCC, where improved algorithms, mainly developed by DST, and a series of software builds will enhance the command and control system.

The JCC will also receive an open architecture Distributed Data System (DDS) that was prototyped in the radar concept demonstrators constructed during the JFSP. The DDS will ease the introduction of new applications into JORN and provide opportunities for SMEs to develop new capability.

BAES is also working with Adelaide University on human factors engineering in the JCC and how to focus operators’ attention on value-added tasks.

“The fundamental concepts behind a lot of these user interfaces have not changed significantly over the years so we’re looking at things like eye tracking and thought processes,” Wynd said. “There’s a lot of nuances about how you operate an HF radar in terms of how you interact with the ionosphere and how the data comes back in that space.”

The radars’ upgrades will be undertaken sequentially, starting with Longreach. This site will be taken offline in 2022 with Initial Operating Capability scheduled to coincide with that of the upgraded JCC in the first quarter of 2024 following initial material release and an extensive program of operational test and evaluation.

Laverton will then be taken out of service for slightly less than two years, followed by Alice Springs, where $30 million of new facilities are also programmed, and which will be offline for a full two years.

“It’s vital that we reduce the integration risk as much as possible. We’re looking to install most of the new system at a radar in parallel with the existing system,” Wynd said. “Before we take the radar down we’ll have a modification readiness review that makes sure everyone is lined up and it’s the right time to proceed with Radar One, we’ll parallel-install equipment in the bunkers and in the control room, and that will allow us to do a lot of pre-set to work and integration before we take the system offline which will increase everybody’s confidence in the timeframe to bring it back online.”

R&D history
Research and development on over-the-horizon radar undertaken by DST and its precursor organisations can be traced back to work on HF radar undertaken in the 1950s by immigrants who had earlier been involved with the UK’s Chain Home and Chain Home Low radar systems.

Even at that time it had been noted from time to time that distortion suggested the signal was no longer line-of-sight but was bouncing off the ionosphere.

A range of studies in the mid-to-late 1960s under Project Gebung moved to a core OTHR research project in 1970, culminating in the commissioning of the Jindalee A OTHR at Alice Springs in 1974, Jindalee B in the early 1980s, and approval in 1986 for the design and development of the OTHR network.

After more than six decades of cutting-edge OTHR research, DST scientists are now progressing capabilities beyond those intended for Phase 6.

Project Coorong, a joint activity with Lockheed Martin, recently resulted in a ‘minimum viable demonstration’ at Woomera of a new DST-developed OTHR receiver antenna architecture technically described as a Regular Over-sampled Sparse Array (ROSA) that provides significant improvement in total sensitivity – presumably the expensive technical solution referred to earlier by Dr Fraser.
A full-size ROSA array would enable JORN to detect and track small, fast-moving targets at extremely long ranges and at night. OTHRs typically operate at lower frequencies at night due to a diminished ionosphere, and this significantly reduces the radar cross section of small targets such as cruise missiles.

“This has verified an idea that is now ready to go if Air Force wants to take it to the next step,” according to Dr Frazer.
A further future capability is mode selective radar (MSR) that utilises four separate propagation paths through the ionosphere to and from a target. This will improve the detection of slow-moving surface ships using multi-input multi-output radar waveforms and an innovative Skewfire transmitting array that is located at an unusual angle to the receive array. DST describes the technology as a world first.

Following the success of a low-powered demonstration system in 2014, a full-scale MSR test will take place next year using a Skewfire array now under construction at Radar Two.

The ability to evolve JORN post-Phase 6 to handle new challenges will be more straightforward than with the present system, Dr Frazer believes.

Hypersonic challenge
Chief among his future concerns is the threat posed by hypersonics – “I think people have lost sight of how profoundly hypersonic weapons have changed the game, but OTH radars can play a role”.

Whereas ballistic missiles fly very high on a predictable trajectory and can be easily seen by traditional line-of-sight radars, hypersonics fly lower and at more than Mach 6, offer propulsion in the atmosphere and can manoeuvre far more readily than current manoeuvrable missile warheads.

“We think there’s an opportunity to see hypersonic missiles at much longer ranges than line of sight radars, however advanced, and this gives you more opportunity to do something about them,” he said.

In more general terms, Dr Frazer points out that space-based surveillance assets are likely to be destroyed in a serious war, restricting surveillance to what can be physically seen.

“In terms of the wavelengths we use, target classes are very different from the wavelengths other radars use so perhaps you’ll see things you might not otherwise see. If you’re not able to rely on anything to do with space, you’ve also got the standoff distance.

“Secondly, smart weapons and smart autonomous systems mean that the inherent location inaccuracy of an OTH radar is less of an issue if you’re trying to guide something to a place; you can reasonably do that now with an OTH radar.

This article first appeared in the June 2018 edition of ADM.