ASKAP - Phased Array Receiver scoops engineering awards

[madbadgalaxyman]

The impressive engineering physics credentials of the CSIRO Radiophysics people are once again demonstrated through the granting of an award for a Phased Array Feed that enables radio telescopes to obtain a very much wider field of view than is normal.

https://www.engineersaustralia.org.au/engineering-excellence-awards-sydney-division/2013-winners#INNOVATIONS

http://www.atnf.csiro.au/projects/askap/ASKAP_Technical_Update_5.pdf

http://www.atnf.csiro.au/projects/askap/ASKAP_Technical_Update_8.pdf

The Australian government funds radio astronomy at a high level, no doubt because of the fact that these people know how to produce useful high technology.

Any of you radio people care to explain how this receiver works??
___________________

Personal opinion piece:

I can't understand why a large slab of the SKA was awarded to South Africa.........

S.A:
- High technical risk.
- Funding difficulties possible, as S.A. is a relatively poor country.
- Significant political risk.
- S.A has a significant background in optical astronomy but little real experience with radio astronomy. Consider for example that SALT had a major optical problem that took a couple of years to diagnose; multiply this sort of problem by a hundred for the case of the SKA.

VS.

Aus:
- Low technical risk; Aus already operates the ATCA, Parkes dish, ASKAP, MWA, and the Tidbinbilla dish.
- Already funded.
- Low political risk
- Demonstrated ability to produce and maintain and operate the technology
- Aus is now equal to the USA or the ESO in radio Astronomy

Therefore.....
My Prediction is:

The SKA will never be built!

Comparison:
The Atacama Large Millimeter/Submillimeter Array, which cost 1.5 billion dollars, almost didn't get completed, because it was a technical and organizational and funding stretch, despite the fact that it was developed by a giant consortium of rich countries including Japan and the United States and the ESO.

[renormalised]

Australia has always been "up" with the US and the ESO in radio astronomy. As a matter of fact, they came to us to learn how to be good radio astronomers, not the other way around. Australia pioneered the field and still leads in it. The only thing that they have over us is funding and the willingness of government and private organisations to put their money where their mouth is. Over here, they spend more on sports teams and digging more holes in the ground than on science and science education. The fact that we punch so high with so little real help is a testament to the quality of our scientists. It's just a pity that so many have to go overseas in order to keep their careers going (or even start).

[Camelopardalis]

Hats off to the guys at CSIRO for ASKAP, and astronomy as a whole here as far as I'm concerned.

From what I understand, the award to SA was part of some developing world benefit, the idea being that if SA does something scientifically significant, it encourages its own scientists and those of nearby nations to aim high.

While it's a nice gesture and all that, I don't feel that major scientific projects should be politically motivated or biased. It should be built by those who can make it work and get results quickly and efficiently. Ultimately the astronomers just want to get their hands on the new instruments and get their research going.

[madbadgalaxyman]

It would be a pity if SKA failed, or ran into serious difficulties, due to the desire to be "charitable" overriding the usual need in science to get the best people on the job and to get the project done in the best way.

S.A. has always had some first rate optical astronomers:
For instance, the late Anthony Fairall was an authority on the large-scale structures, and David Block is a first-rate authority on galaxies. Michael Feast is a very good stellar astronomer and Ian Glass is a well-known infrared astronomer.
So, while I feel that giving a large part of the SKA to S.A. is an unnecessary risk, I do point out, in counterpoint, that S.A. has always been good at astronomy.

P.S.
On a related subject, while Australia does have the right technology for frontier-level radio astronomy, does it have the right people to do radio astronomy with these instruments?
Have a look at the list of research scientists associated with CSIRO radiophysics:
http://www.atnf.csiro.au/people/astro_people.html
My personal opinion regarding the standard of many of the papers that these people have written is .....Hmmmmm.........and Hmmmmm again....
(yes, I have read some of their papers, after searching for them at ADS)( these papers happen to be in personal areas of interest such as the HI properties and kinematics of galaxies, and the disk-halo interface in spiral galaxies)

It is surprising, in my view, for all the efforts of these radio astronomers, how little some of these people have actually discovered!! (I don't think that some of them are the right people for the job)

However, the new bloke at ATNF, Paolo Serra, does have some important discoveries to his credit:
http://www.atnf.csiro.au/people/Paolo.Serra/

Now I could "name names" regarding those people I regard as having a weak record of discoveries.....but I won't. If you want to know who, I can email you their names!!

[gary]

This is not, however, borne out by the facts contained in the SKA Site Advisory
Committee (SSAC) Report and Recommendation of 16 February 2012,

Indeed, one of the considerations was "Factor 8: Political, Socioeconomic, and
Financial". Since South Africa was deemed to have lower rankings in political
and socioeconomic indicators than Australia & New Zealand
and since the other African partner countries had even lower rankings, the
SSAC vote on that factor was actually 14.5 for Australia/New Zealand
and only 5.5 for South Africa.

When the report was made, the SSAC noted that they considered the SKA
as a single instrument and made no evaluation of splitting it.

In the report, the SSAC stated that there were two critical factors that largely
determined the recommendation in favour of South Africa. Though there
were geographic constraints both in Australia and South Africa, the resulting
array configuration was judged to be significantly better in South Africa.
It achieved higher resolution in the North-South directions and better dynamic
range for short observations (less than four hours).

Secondly, the cost of electrical power strongly favoured the South African proposal.
The SKA is estimated to consume 110MW and the South Africans had an existing
power grid in the site area.

In fact five of the seven Technical and Scientific Factors considered favoured
South Africa. For example, the higher elevations of the Karoo gave less
tropospheric turbulence.

Report here - http://www.skatelescope.org/wp-content/uploads/2012/06/117_SSAC.Report.pdf

Other reports here -
http://www.skatelescope.org/the-location/site-documentation/

Best Regards

Gary Kopff
Mount Kuring-Gai
Phone 02 9457 9049

[Camelopardalis]

Both interesting reads, thanks for that!

[madbadgalaxyman]

Thank you very much, Gary, for providing the information from the report about the SKA decision.

The abovequoted conclusion made in the report sounds to me like the sort of off-balance and "pre-prejudiced" conclusion that you would arrive at if you had already made up your mind to give the project to the underdog before you did the so called "evaluation"

Things like tropospheric turbulence and the exact array configuration are not really major issues in the evaluation, but they are being given great weight.

It is obviously much less risky to give the SKA project to a first world country which has capabilities in radio astronomy that are the equal of the very best in the world (= Australia).
(Australia has remarkable numbers of electronic & electrical Engineering Physicists/Astronomers with extensive experience in radio telescopes. In fact, someone once said, a little unkindly, that Australian radio astronomers are - in reality - electrical engineers! )

There are some damn good professional astronomers in S.A, as I freely admit. But technically, organizationally, and politically, I fear that the SKA project may turn out to be too much of a stretch for South Africa.

Whatever happens with the SKA, Australia got ASKAP out of the project, and ASKAP is absolutely a state-of-the-art radio telescope. If I ever get round to it, I might post in IIS about ASKAP's scientific capabilities.

cheers,
Robert

[mswhin63]

To consider the answer for the initial question in this thread, how it works. I do not know the full details but I was given a quick run down while I was working up there on the MWA. In simple terms the individual elements can be phased differently to capture either a broad angle or a narrow angle. I have been too busy with my studies to follow it up.

It seems to be similar to the principle of the phased array for the MWA. Each MWA element can be phased electronically to remain flat on the ground and yet steer it reception based on the rotation of the earth.

It takes approx 8 seconds to acquire an single image, but that information was digested just over a year ago.

[Barrykgerdes]

I have had a glance at the references and can see that the adaptation of the phased array for radio astronomy is quite interesting.

The principle of steering a radio beam using a multi-element array of "sensors" and distorting the phase of the feed to each element of the sensor or radiator has been around for a long time. It is used in TV transmitters to tilt the beam so that the signal does not waste power in an unwanted direction.

It was used in the SPS52 radar fitted to the DDG's of the US and RAN to steer the beam electronically in the vertical direction with mechanical scanning in azimuth. The phase of the elements in the vertical direction was computer controlled (1960's computers with racks of equipment and tape drums).

Radio astronomy aerials are massive devices using very large base line pick up areas to get the sensitivity and narrow beam width required. This means that the mechanical steering at high rate is not practical. However electronic steering by phasing can open up real possibilities, particularly involved with interferometry.

Barry

[mswhin63]

Agreed this is the way to go, although we can't resolve the long wavelengths for radio astronomy at least we can carry out fast switching and phasing to do a more with the signal.

[madbadgalaxyman]

Hey Malcolm and Barry,

Thanks for your explanatory notes!

I am sure I am not alone amongst optical astronomers in finding radio astronomical equipment to be slightly confusing. Just making interferometric radio observations of a single object seems to me to be a difficult and extremely complex and very-time-consuming task, making even an imaging run with a Very Large Optical Telescope seem simple in comparison.

I also have trouble with intuitively conceptualizing frequency;

like most optical astronomers, I do have a real gut feeling for "so many nanometers" or "so many microns" in wavelength, but my mind starts to reel when people talk about GHz and MHz !

cheers,
Robert

[madbadgalaxyman]

A South African point of view about the SKA can be found in a fine set of slides of a presentation by Claude Carignan (see his bio at: http://craq-astro.ca/un_membre_en.php?id=claudecarignan) which was made at the ngCFHT conference in Hawaii in March 2013 :

http://ngcfht.cfht.hawaii.edu/presentations.php

Look for the presentation by Claude Carignan with the title "SKA pathfinders". It is a 31MB .pdf file.

Carignan is a very capable northern hemisphere (Canadian?) astronomer who also used to do a lot of radio astronomy in Australia.

[[ For instance, a lot of the pioneering work on the Neutral Atomic Hydrogen content and the mass distribution within the various Sculptor Group galaxies was done by Carignan. Also, Carignan was important in carrying forward the Galaxy Rotation Curve analyses that helped to characterize the dark matter distribution in the outer regions of disk galaxies. Refer to the search results after googling on the search terms "Carignan + HI + sculptor + group". .]]

No surprises for guessing why Carignan recently moved to South Africa!!
All of a sudden, well known extragalactic astronomers have started to flock to the University of Cape Town.......
(though I might add here that UCT has always punched well above its weight in astronomy)

[[ One of those things that pro astronomers often have to do, just to get a job, is to be willing to hang out in some of the less developed countries that are nonetheless able to access significant amounts of telescope time (Mexico and Brazil and South Africa spring to mind.) ]]
________________________

Madbadgalaxyman's very opinionated opinion of the day:

" If the SKA project can 'civilize' Namibia, which not long ago had a decades long civil war, perhaps it will become safe enough for all of us to move there..... Namibia may have the Best skies on planet Earth"
- R.L.

[mswhin63]

No worries Robert,

Although radio astronomy has been around for a while, the long wavelengths have been difficult to manipulate to get easily readable data. I personally think Radio Astronomy is more an engineering solution in the effort to get data that is usable enough to place in visual form. After it has reached that point then the real science can begin.

This is a place where engineering and science can easily co-exist together without the current snobby attitude I see with most engineering practices.

Anyway the technology is very difficult to intermix with the science and therefore difficult to understand. I originally started to do a double degree in Electronics Engineering and Physics but had to go back to a single degree as the content was too hard to fathom at the same time. So I suspect Radio Astronomy is difficult to take up at the best of times.

I have now recently heard of a relatively unknown option for Radio Astronomy degree at Curtin University where I am so I hope to do that instead of the full Physics degree.

I hope in later times both the science and engineering aspect can be more easily understood than in its current form.

[madbadgalaxyman]

An interesting Perspective, Malcolm, and much more of an "insider's" view than mine (which was arrived at by reading scientific papers written by radio astronomers.)

You confirm, in my mind, the very great complexity and cost of the process of actually making the observations in radio astronomy. It is a long way from what comes in at the receiver to the actually useable data of the sort that an astronomer might publish!

Making discoveries in astronomy is always hard to do, and I suspect that the added complexity of the technology & physics & engineering of radio telescopes may have the effect of reducing the amount of time that radio astronomers actually have to pore over their data. (radio astronomers will struggle mightily sometimes, just to produce data about a single galaxy; so radio astronomy must be a harder game than optical astronomy!)

[gary]

Hi Robert,

Well they find themselves in good company in that, globally, many who are now
or who have been radio astronomers came there via electrical engineering.

And I suspect many who started out as radio astronomers quickly became press
ganged into either hardware or software engineering for radio astronomy
telescope building and instrumentation. :lol:

Historically, many of the pioneers of radio astronomy had strong links
with electrical engineering.

In the U.S., Karl Jansky was Professor of Electrical Engineering at Wisconsin
University.

John Kraus was an Emeritus Professor of Electrical Engineering and Astronomy.

Grote Reber had a degree in Electrical Engineering.
Born in the US, he began experimenting in the late 1930's and there
was a period of a decade where it is said he was the world's only radio astronomer.
In the 1950's he moved to Tasmania where he continued to work.
The University of Tasmania runs a museum in his honor.
See http://www.groterebermuseum.org.au/

Likewise pioneer Bernard Mills who was born here in Sydney did engineering at
Sydney University and was instrumental in the design and operation of the
Mills Cross Telescope with what was then the CSIR.
Obituary here in the Sydney Morning Herald on his passing in 2011 under the heading
"Engineer a star of astronomy" -
http://www.smh.com.au/comment/obituaries/engineer-a-star-of-astronomy-20110520-1ewo0.html

Here is a CSIRO Division of Radiophysics documentary from 1949 -
Part 1: https://www.youtube.com/watch?v=BIhs3yp6zSI
Part 2: https://www.youtube.com/watch?v=DCbbKjOJ1zc
It showcases how the division began just before WWII and designed special purpose
RADARs. After the war, peacetime activities turned to areas such as radio
astronomy.

Here is another made by CSIRO in 1958 -
Part 1: https://www.youtube.com/watch?v=-NVD6tUurVw
Part 2: https://www.youtube.com/watch?v=p1c1LMWCQ_Q

Engineering is applied science. Therefore I am somewhat surprised to hear Malcolm's
comment that radio astronomy is a field where "science and engineering can
easily co-exist together without the current snobby attitude I see with most
engineering practices."

The successful engineering organizations I have come into contact with over my
own career all fully embrace science.

In the case of astronomy, whether at optical or radio wavelengths, the engineer's
"clients", the astronomers, are embedded within the same organization.
The astronomers and engineers are involved in a highly collaborative enterprise starting
from specification all the way through to commissioning and day to day
operation, maintenance and upgrading.

It is no coincidence that radio astronomy has such intimate ties with electrical
engineering. The telescopes are highly sensitive radio receivers after all.

Today, with interferometry commonly employed on long baseline radio telescope
antenna arrays, digital back-ends are all the go. For example, the SKA's realtime
frequency-based cross multiplier correlators have to crunch in the order of
10**15 complex accumulate and multiply operations per second to perform the
required fast Fourier transforms (FFTs). The astronomers have specified the
science requirements and there is so much interdisciplinary overlap that
they are also cognizant of the techniques employed but it is typically the
role of the engineer to recommend and design the architecture and to
deliver the implementation.

In this example. both the astronomer and engineer have the requisite backgrounds in
mathematics and both understand what an FFT is. The mathematics and the power
it provides in many ways form a common language. But typically it will be
the engineers who are best across designing the hardware itself and making
decisions on what type of components would be most suitable.

For example, they will have done a cost benefit analysis between designing their
own full custom integrated circuits or using programmable semi-custom devices.

At the speeds these circuits will operate at, most of the interconnects will be
treated as transmission lines. For digital designers these days, the
speed of light is annoyingly slow to the point that the interconnect delay
through the dielectric of a circuit board, which is typically in the order of
180 picoseconds/inch, is a major pain in the backside. I have been joking to
colleagues lately that if this speed is the best that God can do, he has a lot to answer for. :)
In any case, the black art of dealing with these issues, which themselves are
firmly rooted in Maxwell's equations, is the domain of the electrical engineer
and the astronomer need not bother themselves with this low a level of detail.
Suffice to say that unless they want to roll up their own sleeves and get involved,
the astronomer simply needs to know it is challenging. There is enough specialist
work for everyone.

A few years back, Wildcard Innovations had the privilege of being a contractor
to the Anglo Australian Observatory and we contributed our small part to
some of the embedded software used in the IRIS 2 Infrared camera.

That instrument too went onto win a couple of Institute of Engineers Australia
awards and we were thankful to be mentioned in the AAO's submission.

Whilst working at the AAO offices here in Sydney, which is also on the same
campus as CSIRO radio physics, at times the then head of the AAO, an astrophysicist
by profession, would come down to the lab and inquire as to whether we
were comfortable and was there anything we needed to aid our task.
Wearing the hat of an astronomer, administrator and project manager, he clearly
understood that everyone was on the same team with a common goal. That the
process of successfully engineering the instrument was part of a continuum that
eventually results in the science. Today that same individual is the
SKA CSIRO Director.

Best regards

Gary Kopff
Mt Kuring-Gai NSW

[mswhin63]

Engineering is an applied science, but for some that is forgotten.

It is a different story when the industry is closely related to the science. That is why I feel the close association will remove the snobbishness . In my industry life, I have come across too many technicians and engineers that pile on the I know better attitude.

As a Radio Technician and now a student engineer, I have had some experience in the area. I was during my early years very much like a snob. I now after 30 years in the industry completely grown out of that stage.

[madbadgalaxyman]

Gary,
Thanks for your very interesting Engineering perspective on radio astronomy.
I merely read the papers that radio astronomers write, so I am spared the extreme complexity of the process by which they get their observational results.

I sometimes find that radio astronomers are strange people; there are some I have corresponded with who were so "radio specialized" that they were apparently unaware of very relevant observational data from other wavelength regimes!

I happened upon the 26 meter Mt Pleasant Radio Telescope and the nearby Grote Reber Museum (the location is not far from Hobart), just by chance. The museum is usually closed, unless you make a special arrangement.
A lot of the time I was in cloudy Tasmania, I remember thinking "what a good climate for radio astronomy!"

As you have indicated, the popular story is:
that Reber built a 9-meter paraboloidal radio dish in his back yard in 1937 at his own expense, thus making him the first real radio astronomer, and the only radio astronomer at that time.
There must have been someone else as well (because There always is in science!), but the story is a good one.

((this sort of "great old scientific story" sometimes unravels; for instance, witness our remorseless pulling apart of "Hubble's discovery of the expansion the universe" elsewhere in this science forum ))

Best Regards, Robert Lang