Project Jindalee

But strange lights were part of it. For the launchings, in­itially with the British Black Knight rocket and later the American Redstone, involved lifting so-called re-entry bodies into space which would then be driven back meteor-like through the atmosphere.

Penetrating the official obfuscation, aided in some degree by American and British aerospace journals, one was able to speculate that the “re-entry bodies” were, in fact, simulated ICBM warheads and that the tests were to ‘do with developing anti-ballistic missile defences, particularly ways of detecting and discriminating between real and decoy warheads. In the best traditions of military obscurantism the speculation was never confirmed or denied, and with the conclusion of the trials in 1967 the journalistic interest declin­ed.

Ten years later, in 1977, it was re-awoken with a sugges­tion that we make a film about the Jindalee over-the-horizon radar project. The suggestion came from the then Chief Defence Scientist, Dr John Farrands (now secretary Depart­ment of Science). We had just finished a film called “The 200 Mile Moat”, about Australian defence scientists work in anti­ submarine warfare (ASW) and the development of projects like the Barra sonobuoy. It had been a long and rather ar­duous exercise in terms of almost literally tippy-toeing around the Official Secrets Act. But once the inherent nervousness of the defence establishment was overcome it was accepted that there was, indeed, merit in showing to the general public the pre-eminence of Australian defence scien­tists in certain areas.

At the time the link between Jindalee and the 1960s ac­tivities at Woomera wasn’t clear. In fact, it was only a chance remark by a defence official that alerted us to the idea that there was any link at all. But having been alerted we then proceeded to wrestle – and the word is used, advisedly – the story out of the system.

Although this may appear a somewhat discursive ap­proach into the Jindalee Project (and there’s more to come), I think its important that the story be told. For two reasons: one, it nicely demonstrates how technology can evolve for Jindalee is a product, albeit an accidental one, of those Woomera rocket trials; secondly, the contribution Australian defence scientists made to the global balance of power by vir­tue of discoveries made during those trials gained Australia full membership of the advanced defence science and technology “club”.

Variously code-named Project Gaslight, Project Dazzle and Project Sparta, the Woomera trials were conducted un­der the so-called ABCA (America, Britain, Canada, Australia) defence science agreement. The heavy hardware, rockets and payloads, etc. came from Britain and the US. Australia by providing the facilities of a secure and conveniently remote range, was ostensibly low man on the totem pole. But what Australia, through the Weapons Research Establishment, had going for it, was considerable expertise in long-range radio wave propagation, and it was this that was to lead to a crucial discovery early in the trials.

The discovery was this: as rocket, after launching, passes through the ionosphere, the ionised layer in the upper atmosphere on which long range or high-frequency radio is dependent, it literally punches a hole. In so doing it creates shock waves. The shock waves create turbulence in the “sea” of ions and electrons. The turbulence, in turn, disturbs the ionosphere’s reflecting- layers. Radio waves bouncing off those reflecting layers are changed.

The implication of this discovery was that if radio waves were selectively beamed in the area where rocket launchings occur it should be possible to detect such launchings at very long range by detecting any changes occurring in the nature of the radio waves.

The Americans and the British were quick to capitalise on the discovery, and so was born the first effective over-the­ horizon radar system in the guise of what was known as Pro­ject 440-L. In Japan the Americans built a very high powered transmitter which radiated high-frequency radio waves out over China and southern Russia, the regions where rocket launchings were most likely to occur. These transmissions were picked up in Europe and the Middle East – one station was on Cyprus. If a rocket launching occurred analysts at the receiver sites would be able to infer the occurrences from changes in the radio waves.

The effect of the system was that the Russians, in par­ticular, lost the strategic element of surprise. The balance of power or terror underwent one of those subtle shifts.

The technique was called over-the-horizon radar in the forward scatter mode. It was basically a fairly crude techni­que; and, as radar, in the true sense, it was not, for no signals were being returned to sender.

The development of a true form of over-the-horizon radar would require the exploitation of another phenomenon associated with high frequency radio transmissions. This phenomenon is called back-scatter.

It had first been observed in the 1920s by radio workers engaged in radio photo-transmissions between England and America. They found that some of their transmissions were bouncing back to them. At the time this spurious feed-back had more nuisance value than anything.

In the context of the cold war, however, with the impelling need for ever more effective techniques of surveillance, the phenomenon took on a new significance. For if signals could be bounced to targets thousands of kilometres across the horizon and returned to sender in real time early warning capacity would be greatly enhanced. But how to exploit back­-scattered signals which were invariably weak – and also buried in a lot of other radio noise? The solution, in part, came from the Woomera trials.

Their ostensible primary purpose had been the detection of incoming warheads. In the passage of the re-entry bodies back lo earth, the friction of re-entry turned them into fiery gaseous blobs trailing a long ionised wake: a kind of space­ age sm0kescreen which obscured the real targets. It was determined that the only way that the “smokescreen” could be penetrated was by having the (conventional microwave) radar signals aimed at and returned from “the blob”, processed in real time by very powerful computers.

What the Australians, and the Americans, engaged in the projects realised was that high-speed signal processing was also the solution to the back-scatter problem with high fre­quency radio. By marrying the two technologies of radio and of computer processing it should be possible to produce an effective and true form of over-the-horizon radar. And, so, more or less, was born, as it is now known, OTH-B – over-the horizon radar in the back-scatter mode.

The Americans, drawing to no small extent on Australian inspiration, have gone ahead with quite extensive developments in OTH-B systems.

In Australia the proposal to build such a surveillance system formally emerged from the Weapons Research Establishment in 1969. The soubriquet “Jindalee”, reflecting WRE:s penchant for giving its home-grown projects aboriginal names (e. g., Nangana, Mulloka, Barra, Jindivik, Jabiru, etc. ) was chosen by some joker because, in one inter­pretation, it stands for “bare bones”, and that was thought to be an appropriate description of the level of the funding the project got ($6 million to date). Adopting some licence this writer has also defined it as “scarecrow” as being appropriate to the concept of defensive surveillance which the defence science people are promoting through their work in OTH radar and also in sonar systems: to make an intruder aware that he’s being watched, or listened to, and therefore, perhaps, wary of intruding further.

The idea behind the Jindalee Project (before it came to be named as such) was that a single over-the-horizon radar system operating from the centre of Australia would be capable of providing surveillance over comparatively enormous distances and volumes of air – and sea – space. In cost-effectiveness terms, alone, it would make nonsense of ideas of having a picket of line-of-sight radars around the coast. Whereas conventional radar might give several minutes warning of an incursion, 0TH radar could give several hours, allowing for any repelling action to be fought outside Australia.

(The essential difference between 0TH and conventional radar is that whereas 0TH uses comparatively long wavelength or high frequency transmissions which bounce off the ionosphere the much shorter wavelength microwave or very high frequency signals of line-of-sight radar tend to go straight through the ionosphere at the horizon and on into space, the 0TH transmissions bouncing off the ionosphere also can “illuminate” a vast area.)

The attraction of the OTH-B concept for a country ner­vous about its northern neighbours is quite obvious, and the Jindalee radar is now operating experimentally in the Alice Springs region. The emphasis, incidentally, will remain on the “experimental” for some time to come, for, as we’ll see, there are “bugs” to be ironed out before it can be said to be effec­tive. The same applies with the systems the Americans have developed, and, also no doubt, with those that the Russians have developed.

There are two main elements in the Jindalee system: the transmitter and the receiver.

The Jindalee transmitter sits in the Harts Range about 160 kilometres north of Alice Springs. The receiver, with an array of whip-type antennae, is 100 kilometres away, closer to the Alice at Mt Everard. The distance between the two sites is dic­tated by the need to prevent interference between the transmitted and received or back-scattered signals from dis­tant targets.

It’s a measure of the contribution the Australians have made to the concept of over-the-horizon radar that the Americans have provided much of the hardware – transmitters, antennas, etc. – for Jindalee. The Americans are also providing obsolescent transmitters (presumably from the former Project 440-L facility in Japan) to boost transmission strength in Jindalee’s next experimental phase.

(Under the terms of the agreement by which our film was made, this writer is not at liberty to discuss transmission strengths nor the range of the system – except in the very broadest terms of several thousand kilometres.)

The major problem for the Jindalee system, and, for any over-the-horizon radar system, for that matter, is the ionosphere, the reflecting mirror on which it depends. The problem is that the ionosphere is highly unstable, susceptible to storms on the sun with their great outpourings of protons which increase and disturb levels of ionisation. Auroras appear to generate winds in the ionosphere which blow ions around in great invisible clouds. Eclipses produce a cooling effect, which as the eclipse shadow moves along at supersonic speeds creates a cold shock-wave effect in the ionosphere. Gravity waves arising from irregularities in earth’s surface can produce valleys 100 kilometres or more long in the bottom­ side layers in which signals can get lost or thrown back from a completely wrong direction, as though looking through a glass badly.

In fact, as a mirror for over-the-horizon radar the ionosphere is more like a collection of those Luna Park variety mirrors.

In coming to grips with the perturbations of the ionosphere Jindalee presently relies on an ionospheric sounder to determine the state of the ionosphere’s weather. Sounder signals are analysed by a computer at the receiver site, which in turn tells the transmitter the best frequency to operate on. All this is done in real time.

Ultimately, Jindalee will require access to more elaborate information, to data coming from systems which maintain surveillance not only on the ionosphere but also on the sun. In the east of Australia such a facility operates at the CSIRO – Ionospheric Prediction Service observatory near Narrabri, NSW. A facility to be established at Learmonth, WA by the IPS and the US Air Force is also expected to contribute.

For the time being, however, the net effect of the vagaries of the ionosphere on the Jindalee system, as it presently operates, is that it is not particularly accurate in terms of position fixing, which means that it can’t yet be ex­pected to do the kind of vectoring that might be expected of it in some future tactical or combat situation.

Target resolution may be improved by the use of forward monitoring stations – off-shore – to provide differential fix­es. It may also improve as the system goes to higher transmission powers with a concomitant increase in the sophistication of the signal processing system.

(The signal processor – the proverbial “black box” – is the real heart of Jindalee. A micro-miniaturised computer embodying a large number of micro-processors, it was designed and built at WRE. In fact, the requirement for the kind of micro-electronics technology on which Jindalee relies was, as it turns out, a principal factor in the decision in 1967 to foster, by way of Government subsidies, the development of a local self-sufficiency in the design and fabrication of micro­ electronic devices – a move ‘. which was not greeted with much enthusiasm by the electronics industry at the time, but which would appear to have paid off.)

For the time being, Jindalee tracks “targets of oppor­tunity”: commercial aircraft on the Singapore to Sydney route. Data on aircraft movements relayed through Air Traffic Control at Alice Springs Airport are used to check the perfor­mance of the system. (The main reason for the present siting of the Jindalee system is that it straddles the A-76 air-route. )

Following on American experiments in which OTH-B radar has successfully tracked ships at sea, Jindalee is also be­ing engaged in experiments to track ships off the north-west coast.

It is doubtful that it will be capable of tracking small vessels such as fishing trawlers operating illegally in Australian waters simply because such vessels have neither the velocity nor the mass to produce a detectable Doppler shift in the radar signal. On the other hand, light aircraft engaged, say, in drug-running, would have the velocity to produce a detec­table frequency shift.

One thing Jindalee may also be able to do is to provide early warnings of cyclones. With signals back-scattered off a mass of turbulent sea it is possible to infer wind directions and velocities, and from this provide more up to date information on the genesis and movement of cyclones than is possible with present meteorological warning systems, including satellites. 0TH radar has, in fact, been used experimentally as a meteorological device for some years by physicists at James Cook University, Townsville.

On a more sensitive note, it will also undoubtedly have potential for gathering ELINT – electronic intelligence – simply by nature of the radio system that it is. That, however, is matter that is not spoken about in unrestricted circles.

For long distance aerial and coastal surveillance Jindalee promises to be the key element in a centralised command and control system – something Australia has never really had. Defence’s Central Studies Establishment has already done studies on its role in continental air defence, and the question of compatibility between Jindalee and contending aircraft to replace the Mirage has also been engaged by the Tactical Fighter Force committee.

Whether there will be ultimately one or two “Jindalees” has yet to be determined. The WRE people talk of two systems, working in overlap – one, as now, covering the north-western approaches, the second covering the north­ eastern approaches. Perhaps they might also consider a third, southerly-looking for the event that the resources battle for Antarctica “hots up”.

How all the data deriving from Jindalee type systems and other surveillance systems, such as sea-bed sonar, will ul­timately be used and displayed remains also to be deter­mined. Perhaps eventually there may be some vast electronic war-game room operating in a bunker somewhere – a la NORAD in Colorado. Jindalee, after all, is predicated on the circumvention of some future “battle for Australia”.

By now Jindalee is perhaps beginning to sound like some electronic guardian angel for all that worries Australia. It’s not, of course. But Jindalee is one of the most significant developments to come out of defence science and technology down under – significant not only in the scien­ tific and technological sense but also in the sense that it, and related developments, are forcing a more scientific approach to defence planning and strategy.

This writer’s only regret is that he didn’t know about it 10 years ago when it was all just beginning to happen. It would have made a good story!