Ferranti radars - Blue Falcon / Blue Hawk / Blue Vixen

Mike Pryce

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Does anyone have any details of the Blue Vixen radar? I have some old Jane's/Flight articles, and the 1994 GEC Review one, but I am curious as to its modes of operation as well as any updates it received in service. As it is the basis for Captor, similar to PS-05, and now out of service, it is strange that it is so mysterious. And is it true that Blue Falcon was simply the breadboard version?

In addition, what happened to Blue Hawk? I have a Janes Defence Weekly article from 1992 on it, and web refs saying it was COTS based, but did any get built beyond rigs? And how did it compare to Blue Vixen (were they related?)?

Seems Blue Vixen was a real success story. Is that why it is little known???!!!
 
It was certainly an extremely successful radar design. In fact, you have to go back to Blue Fox Mk 2 to get the full picture.

Blue Fox (ARI 5982) was largely an adaptation of the Seaspray radar to form an "off the shelf" fighter radar. Design was prematurely frozen in 1982 for the Falklands War. In 1984, upgrades (Blue Fox B?) were made to the processor, scanner and receiver which significantly improved it. The radar was extremely reliable; some Blue Foxes operated right through to the MLU in 1992 without repair. The next stage in development was Blue Fox Mk 2; essentially this was mostly pre-development work which fed into Blue Vixen and CAPTOR because Blue Fox was withdrawn soon after upgrading to Mk 2 was completed. Blue Fox Mk 2 incorporated two ECCM technologies, ILIC (In Loop Interpretative (or Integration) Control) and Anderwave (after the designers, Anderson & Waverley) which were subsequently used on Blue Vixen and ECR-90. This system was top secret; after Blue Fox Mk 2 was withdrawn from service, all systems had to be physically scrapped, despite intense overseas interest. All drawings were burnt.

Blue Vixen (ARI 50019) was a superb radar design. It hadn't been possible to make Blue Fox a lookdown/shootdown pulse doppler radar due to time constraints and a lack of suitable industrial and knowledge base. Armed with money and experience from Blue Fox, Ferranti started the Blue Falcon demonstrator program. This became the prototype for Blue Vixen.

For Blue Vixen, Ferranti eschewed the simpler high PRF route which Marconi were following with AI24 Foxhunter and went full speed into medium PRF pulse doppler radar. This gave excellent all-aspect lookdown performance. In terms of rival radar designs, it is ahead of APG-65, more comparable to the (heavier, larger) APG-73. While Blue Vixen was initially required to track 12 targets, Ferranti aimed (and achieved) for an internal target of 28.

Don't have anything on Blue Falcon unfortunately.

Regarding Blue Vixen modes, it depends a lot on how you classify between mode and submode. 11 major modes sounds about right.
 
Very interesting. I knew Blue Fox had some post-Falklands updates, using some of the experience from the conflict (bombing from IP mode and others IIRC) but was unaware of a Mk.2. Seems a pity they were scrapped - surely one or two were kept somewhere?

For Blue Vixen, I read online it got added A-G capability beyond its initial real beam mapping, with a fair SAR capability added. Is that the case?

The 1994 GEC paper says Blue Falcon was renamed Blue Vixen as the RN wanted to keep the Vixen name going, although I have found references to Blue Vixen as XR201 (UK project code) 'based on Blue Falcon', which appears to indicate a less direct link.

Is it the case that John Roulston was the key person behind all this? He seems to be one of those all-round engineers with leadership and management skills that such projects need.

Pity Blue Vixen's technical success was not reflected in sales to Australia etc.

BTW, tried to PM you back Overscan but the verification image/sound does not work, on either computer I use. Any tips? I can read yours though - thanks for that. I will send the full reply when it works.
 
Found Blue Hawk info, from International Defense Review, 8&9 1992.

X-band, high, medium and low PRF pulse-Doppler radar. 44nm look up range, 27nm look down. Ground mapping 120 degree sector to 80nm. Air cooled, 107kg weight, 2.5kVA prime power output, waveforms transmitted at 8kW peak and 160W mean from ring bar TWT, PRF 800Hz-90KHz. Four LRUs, plus planar antenna with three direct drive DC motors. Separate programmable signal, data and display processors (RDP 68020) using 'C' language for data and display processing and assembler for signal processing. 1553B databus and HOTAS compatible.

Modes - look up, look down, velocity search, HUD FOV, single target track, DBS, freeze display, surface track, two sea search modes. Could be expanded to include AMRAAM, TWS, GMTI, NCTR and TA.

Aimed mainly at retrofits, no antenna size given but seems similar to Grifo/Elta 2032 so I assume it could be tailored to fit applications. I assume it was aimed at the same market Ferranti's 4510 HUD, MED 2060 and FINAS sytems were aimed at - Mirage III/V, F-5, Mig-21, Skyhawk etc, plus new light aircraft such as Hawk 200. Expected to be ready for service in 1995 - the articles include pictures of a space model and an antenna on test.

Also found a recent online mention of it being currently considered for Pakistan's FC-1 fighters, but assume the new Selex Vixen 500E is more relevant.

So, it seems to fill the gap between Blue Fox and Blue Vixen, but no sales it seems.
 

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Here's info from Jane's Avionics 1999

Blue Hawk radar
The Blue Hawk is a new I-band lightweight, coherent, multimode pulse Doppler radar designed for both new lightweight fighters and for the upgrade market. It employs low-, medium- and high-PRF waveforms and offers multiple functions for air interception, close air combat, air-to-ground and anti-ship operation. Aimed at today's typical threats, Blue Hawk has substantial processing capacity to allow it to be matched to a customer's particular requirements, and to adapt to future changes in the threat.
Blue Hawk weighs 107 kg and consists of four main elements; transmitter, receiver/exciter, combined display and data/signal processor, and the antenna. The modular design allows flexibility of installation, especially in platforms where space may be restricted. Blue Hawk is fully compatible with MIL-STD-1553B databus and may be integrated readily with a total avionic system. It is compatible with a wide range of current weapons and ordnance. A major feature of the design philosophy is the wide use of standard components and conventional manufacturing technologies. Blue Hawk employs a fully programmable digital unit comprising signal, data and display processing, with 50 per cent spare throughput and 50 per cent spare memory capacity for growth. It is optimised for HOTAS control. A number of inherent design features minimise the effects of ECM.


Specifications
Frequency: I-band (9.6-9.9 GHz) frequency agile over multiple channels
Antenna: planar-array mechanically scanned +60º in azimuth and +60º in elevation. Antenna size can be varied to suit installation
Receiver/exciter: 2-channel receiver plus frequency generator
PRF: wide range from (low PRF) 800 Hz to (high PRF) 120 kHz
Power output: 8 kW peak; 160 W mean, a 400 W option is available
Detection performance: 51 n miles in look-up mode; 30 n miles in look-down mode; out to 80 n miles in ground-mapping mode
CW illuminator: can be offered as an integrated option for MRAAM control
Weight: 107 kg
Power requirements: 2.5 kW, 400 Hz, 3 phase


Operational status
Blue Hawk has completed the ground proving stage of development and has undergone a flight trials programme within the UK.

Contractor
Marconi Electronic Systems, Marconi Avionics Limited.
 
Interesting to hear it flew, and with only a few changes it seems.

I assume it had all the best 'bits' omitted for export, e.g. on Blue Vixen the antenna was scanned electronically in roll, but Blue Hawk seems to use 3 axis mechanical scan. I would expect an amalgam of Blue Fox/Vixen/Captor technology plus COTS.

I wonder if Blue Vixen was updated in service to make it 'Super' (e.g. SAR modes)?
 
Overscan mentions a 1984 update of Blue Fox and a Blue Fox Mk2. A repackaged Blue Fox known as Red Fox was proposed for the JF-17 Thunder in the early stages of the programme. Most intriguing. Does anybody have any further information on these Blue Fox variants? Also, what does IP stand for in relation to radar mode? Is it Initial Point?

Nova
 
Aah, my first ever post and thread on the forum come back to life...

Red Fox was simply Blue Fox re-packaged for aircraft other than the Sea Harrier.

IP does mean initial point.

Attached is an old document (a bit squirly due to several computer changes) I did in 2007 when trying to sort this all out. Has errors and omissions no doubt, but may be useful for some.
 

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Most interesting. I always thought PS/05A was a development of Blue Vixen rather than Blue Falcon.
 
Blue Falcon history seems to be all over the place, I have seen it said that the programme started in 1975 and 1980 though the latter seems to be the consensus. Apparently it was never built as a complete set but rather it seems to have been an evolving engineering prototype core that became the grand-daddy of the latter Ferranti family with technology apparently being used in Blue Kestrel as well as ECR-90, Blue Vixen and the Ericsson PS-05. Super Vixen is said to have been a developed Blue Vixen as a fall-back solution for ECR-90 rather than a direct predecessor to it and thus a Blue Falcon grand-child? Work on Blue Hawk, based on the fact that when it was announced in 1992 was said to have been going on for three years, must have begun in 1988-89 and I would suggest that there is little if any Blue Fox in it- likely almost all Blue Falcon in it's lineage. Blue Hawk, along with the Marconi Apollo EW system and the Alenia ASPIDE was supposedly chosen at one point (around 1992) for the Chengdu Super-7. The GEC-Marconi Super-Skyranger was eventually chosen for Pakistani J-7Es with the original Skyranger used in earlier variants. Blue Falcon seems to have started as a private venture though there was certainly some government research contracts given along the way and Blue Hawk was also a private venture.
 
Medium PRF systems offered the possibility of avoiding the problems with high PRF sets very limited range discrimination, limited capability against retreating targets and relatively high probability of transmitter pulses obscuring or eclipsing target returns.
MEASL and Ferranti both proposed lightwieght PD AI radars for a successor to the Jaguar and Harrier in '76-'77. Trials ran from May '82 to start of '84 and where fed into Blue Vixen.
 
zen said:
Medium PRF systems offered the possibility of avoiding the problems with high PRF sets very limited range discrimination, limited capability against retreating targets and relatively high probability of transmitter pulses obscuring or eclipsing target returns.

chapter 4 on "Pulse Doppler Radar" in Skolnik's "Radar Handbook, 3rd ed" has a pretty good treatment on medium vs. high prf pros and cons:

medium prf advantages:

- performance at all target aspects
- good ground rejection
- measures radial velocity
- less range eclipsing than high prf

medium prf disadvantages:

- performance limited by sidelobe clutter
- range and velocity (radial) ambiguity resolution required
- low antenna sidelobes necessary
- ground target sidelobe returns rejection needed

high prf advantages:

- allows thermal noise-limited detection of targets with high radial velocity
- single doppler blind zone near zero velocity
- good ground rejection
- measures radial velocity (unambigious doppler)

high prf disadvantages:

- limited low radial velocity target detection
- range eclipsing
- range ambiguities preclude pulse delay ranging
- high stability required due to range folding

in radars with the requisite mixed prf capability the chapter describes the advantage of the use of high prfs for forward-aspect search at extended ranges for closing targets, while using medium prfs for all-aspect search, and doing them in an interleaved fashion in order to use the advantages of one prf to complement the other prf...
 
After the Falklands war, the U.K. Navy, driven by the fighting record of the Sea Harrier, decided to upgrade its weapons system. At FRS-1 standard the aircraft carried two AIM 9L missiles and the Blue Fox radar was competent only for engagements over sea where the clutter situation was fairly benign. The navy’s ambition stretched to four AMRAAM and full look-down, shoot-down targeting performance. Ferranti won the contract against competition in the U.K. and the U.S. and the result was Blue Vixen, a compact, multi-mode air interception radar with a range of new features, previously untried in this type of radar. In Blue Vixen, high, medium and low PRF modes were scheduled automatically in track-while-search, the radar deciding on which waveform would give the tracker the most useful information on an instant by instant basis. The design held many breakthrough features, among them constant mean power on the three PRF modes, extremely high levels of automation, high clutter rejection and the ability to launch and provide accurate mid-course guidance to AMRAAM with high covertness. The Harrier (designated now, F.A. 2) with Blue Vixen and AMRAAM can outperform much more modern platforms as shown by trials against the Australian navy F-18 fleet. One Sea Harrier pilot has commented that with Blue Vixen performing an intercept was "down to selecting 'air to air', pointing the aircraft in roughly the right direction, and leaving the radar to it." It is regarded as state of the art among fighter radars.
The post-war development of fighter radar in Europe - A British perspective - John Roulston.

 

A little bit on blue vixen’s DBS
 

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Edinburgh's first line of defence​

IT WAS the mid-1980s. The Berlin Wall had yet to fall. And the Royal Navy, determined after the Falklands War to improve the performance of its Sea Harrier - Britain’s home-bred fighter aircraft - was conducting an air-to-air combat exercise in the Australian desert.

By The Newsroom
23rd Jul 2004, 2:33am

The F-18, the Americans’ equivalent of the navy’s flier, was regarded by the US military as the superior plane. "A better airframe," as they put it. But the navy had recently asked British Aerospace, to upgrade the Sea Harrier’s air-to-air missiles. And to guide its launches they had commissioned and installed a radar system that was "technologically impossible" - or so said the Americans.

On hand in Australia to witness the improved Sea Harrier’s early trials were several top brass from the US military, and a number of their British counterparts. Eagerly awaiting the results back home, in Edinburgh, was the man who had designed that impossible radar - Professor John Roulston.

Flying against a swarm of F-18s, the Sea Harriers deployed their new missile and radar systems to devastating effect. The American planes were defeated time and time again. The exercise over, a US general conceded the Royal Navy’s new-found superiority. Lowering his field glasses, he announced his grudging admiration. "So it’s the poofy jet with the big stick," he drawled, to Roulston’s great delight.

Roulston has spent the past 37 years living and working in Edinburgh, designing groundbreaking systems like the Blue Vixen radar in the Sea Harrier. One of the world’s top three radar experts, he has brought billions of pounds of business to Scotland since joining Ferranti, the electronics firm that is now part of BAE Systems. In September he will become chief executive of one of BAE’s core suppliers - Yorkshire-based Filtronics. But he will keep his home in Edinburgh, and says his new role will let him mastermind the next wave of technology needed to underpin BAE’s radars of the future - boosting its Scottish business.

Ferranti’s operation in Scotland dated back to the 1940s, and the nucleus of the post-war Scottish electronics industry. By the late 1960s it had become Edinburgh’s top defence sector employer. Roulston, attending university, saw two attractions of living and working in the capital in the summer of 1967.

There was the Festival, and there was a local girlfriend who happened to work at Ferranti.

Roulston wanted to work in hi-tech, and in those days that meant defence. Ferranti was not only the premier name, it also had several exciting sidelines including the first digi-TV for the London Stock Exchange, and high speed printing peripherals for computers - unheard of in those days.

"So I knocked on their door," says Roulston, "and at first they said, ‘We don’t take first-year students.’ But fortunately the HR officer in those days was a physicist. It wasn’t too difficult to draw him into a technical conversation..."

Awarded one of two placements, Roulston earned 9 that summer. He came back for the internship - and the Festival and his girlfriend - for the next two years. In 1970, he landed a full-time post after graduating, receiving an engineer’s starting salary of 1,300, with a possible bonus of 50.

By that time huge changes were afoot in the UK defence industry. The Wilson government had scrapped the TSR2 project - the last aircraft program that was truly British, rather than an international collaboration - in 1966. Ferranti had built a terrain-following radar for the TSR2, allowing it to fly "knap of the earth". But when the project was scrapped, the technology died with it. By the early 1970s Ferranti was looking to develop a new radar without any apparent hope of a contractor.

It lost out on the system for the GR4 Tornado after the Americans pressured the Germans to install a US-built radar- an early lesson, Roulston says, that political and commercial nouse would be as important as his engineering skills. There was more bad news to follow. With the second breed of Tornado, Ferranti was made 40 per cent subcontractor to Marconi - awarded the lead role by the government.
"The company drew me aside. They said: ‘We don’t want you involved in that project. The way to respond is with technology. Keep the good ideas to ourselves.’ And that’s how the Harrier came to be."

Roulston was asked to lead a small team of mathematicians and engineers to design a revolutionary new radar, based on research ideas concocted as early as 1973. The arrival of digital information and microprocessing had opened up huge opportunities to translate mathematical ideas into electronics. As late as 1981 the project was still without a contractor. But eventually it was bought by the Swedes for their Gripen. Then came the Sea Harrier.
"It was a period where engineering preceded everything," says Roulston. "It was an era before Cadbury, before corporate governance and shareholder interest. Every project went over budget, often by a factor of three. Ferranti was still a family business, just interested in engineering. When the Harrier opportunity came along, we were way ahead of Marconi. They had nothing to offer technologically."

Eventually Ferranti took over Marconi’s radar business. "But there is no point in looking back nostalgically at times past," Roulston stresses. "The competition comes in on budget these days and you’ve got to do the same. Let’s not forget the company hit a cash flow crisis and Wedgie Benn had to bail us out with 15m from the Labour government." The company floated, its shares recovered, and the government got its money back at a huge premium.

After the Sea Harrier’s success, Ferranti was ready for fresh opportunities, and Roulston turned his attention to the next great project already on the horizon in the 1980s: the Eurofighter. It was here he did some of his best work on the commercial side of the business, rather than in engineering. The radar contract won, Roulston began tackling the huge new challenges it created. "The risk was making it with European partners who’d never done that work before - to satisfy the political agenda - while still making a business out of it.

"So I focussed myself on learning to do business that way. Learning the languages, for example. We found the idiomatic nature of English got in the way. An engineer who was a little bit nervous in a presentation would use imaginative language rather than simplicity and repetition. He’d say, ‘Do you understand’, and everyone would nod. But later it would transpire that no-one had understood at all."

Once those problems were ironed out, "we began to respect the engineers we were working with - we realised there were very good engineers working outside the UK". Another skill was mastering the colossal length of the project cycle, and planning product obsolescence and development despite the fixed-price regime introduced under Margaret Thatcher.

"The Eurofighter bid pegged its prices in 1990 [when GEC took over Ferranti’s radar business]", Roulston explains. "I remember the business case I put forward to [GEC chairman Lord] Weinstock. I told him we’d be cash neutral in about 2015. And I think that’s still right. But when people heard me say it would take 25 years, they said I’d be out of a job. Well... they were wrong. Weinstock took the view that it was the price of being in the business. And he was right."

BAE, which later took over GEC’s radar business, got its production contract in 1998, and the first radar shipped in 2000. At 2m a piece, 120 have been sold to date. The Eurofighter order is expected to total 620 - about 1.25 billion of business.

It marked another huge leap in innovation. "We made a supreme product that took us into the next generation, which is what you’re always aiming to do," says Roulston. And true to form, Roulston has since been leading BAE’s "blue-sky thinking" for the next generation of radar, done in Edinburgh. The technology pioneered in the Eurofighter will take a new twist, with a transmitter located on one vehicle and the receiver on another. With covert communication it will be impossible to detect the radar is operating. BAE has already flown experiments with prototypes.

Roulston says he will keep two achievements at the front of his mind after he leaves BAE Systems. "Commercially, I think my peak was leading the Eurofighter consortium, particularly the concept of the Single Equivalent Company - the idea we’d better behave like an SEC, because our competitors, typically in the US, usually are. Meaning we had to get our efficiency to a point where we could compete. That single thought - a bit of homespun philosophy - has solved so many arguments!

"In engineering, the zenith for me was the Blue Vixen in the Sea Harrier. It looked technically impossible. It achieved world accolades. I don’t think I’ll better that."
 

A pretty good review of Blue Vixen!
 
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Blue Falcon history seems to be all over the place, I have seen it said that the programme started in 1975 and 1980 though the latter seems to be the consensus. Apparently it was never built as a complete set but rather it seems to have been an evolving engineering prototype core that became the grand-daddy of the latter Ferranti family with technology apparently being used in Blue Kestrel as well as ECR-90, Blue Vixen and the Ericsson PS-05. Super Vixen is said to have been a developed Blue Vixen as a fall-back solution for ECR-90 rather than a direct predecessor to it and thus a Blue Falcon grand-child? Work on Blue Hawk, based on the fact that when it was announced in 1992 was said to have been going on for three years, must have begun in 1988-89 and I would suggest that there is little if any Blue Fox in it- likely almost all Blue Falcon in it's lineage. Blue Hawk, along with the Marconi Apollo EW system and the Alenia ASPIDE was supposedly chosen at one point (around 1992) for the Chengdu Super-7. The GEC-Marconi Super-Skyranger was eventually chosen for Pakistani J-7Es with the original Skyranger used in earlier variants. Blue Falcon seems to have started as a private venture though there was certainly some government research contracts given along the way and Blue Hawk was also a private venture.
Any information on how Super Vixen differed from Blue Vixen and Captor?
 
From 'Review of United Kingdom Radar' by J. Clarke (Royal Signals and Radar Establishment), D.E.N. Davies (University College, London), M.F. Radford (Marconi Research Centre) published in the Institute of Electrical and Electronics Engineers 'Transactions on Aerospace and Electronic Systems Vol.AES-20, No.5', September 1984 (Link). It covers most areas of UK radar at the time and in relation to airborne radar it generally talks about Blue Fox, Blue Falcon and ongoing research for future radars. However, one piece did stick out:

Marconi Avionics also manufacture a lightweight X-band airborne ranging radar consisting of only 3 line replaceable units (LRUs); it is suited to small airframes and is especially suited for retrofit into MIG21 [Mig-21]. The radar provides range and range-rate measurements for gun and missile fire control. The radar exhibits pulse-to-pulse random frequency agility over more than a 5 percent RF range. Range resolution achieved is 150 in. Output is by way ot an ARINC 429 highway. The equipiment weight is 37 kg and the cooling is by conduction and radiation;power consumed is about 400 W.

Is this Red Fox? Or an earlier incarnation of it?
 

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The attachments, as the text etc says, is the Blue Fox radar for the Sea Harrier FRS.1, which entered service in 1978.

What you are asking about in the quoted paragraph above the attachments, does indeed seem likely to be Red Fox.
Red Fox (which I posted a short entry {with photo} on in this thread back in 2015 in post #13) was a later repackaging of Blue Fox into a smaller-diameter package (the electronics - the dish remained the same size) for aircraft with smaller noses.
 
From 'Review of United Kingdom Radar' by J. Clarke (Royal Signals and Radar Establishment), D.E.N. Davies (University College, London), M.F. Radford (Marconi Research Centre) published in the Institute of Electrical and Electronics Engineers 'Transactions on Aerospace and Electronic Systems Vol.AES-20, No.5', September 1984 (Link). It covers most areas of UK radar at the time and in relation to airborne radar it generally talks about Blue Fox, Blue Falcon and ongoing research for future radars. However, one piece did stick out:



Is this Red Fox? Or an earlier incarnation of it?
I think it is Skyranger. See https://cdn.rochesteravionicarchives.co.uk/img/catalog/ZZ_1395091157_DDBR0114+(O&A-1b).pdf
 
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