Forgot your password?
typodupeerror
Space Science

When Lofar Meets Stella 123

Posted by timothy
from the hill-people-rejoice-aloud dept.
Roland Piquepaille writes "The LOFAR (Low Frequency Array) telescope is a new IT radio-telescope which will use about 20,000 simple radio antennae when it's completed in 2008. At this time, it will cover an area with a diameter of 360 kilometers centered over the Netherlands. Its small radio antennae will detect radio wavelengths up to 30 meters, and because the ionosphere can bend some of these radio waves, the Lofar images might be somewhat blurry. So all the information captured by these antennae will be digitized and sent to a computing facility at a rate of 22 terabits/second today, and almost 50 terabits/second in 2010. This is the reason why Lofar needs Stella, an IBM supercomputer installed recently in Groningen, also in the Netherlands, to process signals from up to 13 billion light years from Earth. Stella consists of 12,000 PowerPC microprocessors and has a computing power of 27.4 teraflops. This overview contains more details and a picture about the Lofar-Stella interaction."
This discussion has been archived. No new comments can be posted.

When Lofar Meets Stella

Comments Filter:
  • But can they control the weather or blow up the earth with it?

    /HAARP [rotten.com]
    • Oh come on, we all know that this super computer will really be used as a listening post by the government to ensure that nobody is pirating any of Tennessee Williams works...

      They should just drop the guise and name the array "Harold".
  • OOooo (Score:5, Funny)

    by Anonymous Coward on Sunday May 01, 2005 @08:01PM (#12402444)
    Stella consists of 12,000 PowerPC microprocessors and has a computing power of 27.4 teraflops.

    I love it when slashdot talks dirty.
  • by Anonymous Coward on Sunday May 01, 2005 @08:04PM (#12402472)


    When Lofar Meets Stella

    The LOFAR (Low Frequency Array) telescope is a new IT radio-telescope which will use about 20,000 simple radio antennae when it's completed in 2008. At this time, it will cover an area with a diameter of 360 kilometers centered over the Netherlands. Its small radio antennae will detect radio wavelengths up to 30 meters, and because the ionosphere can bend some of these radio waves, the Lofar images might be somewhat blurry. So all the information captured by these antennae will be digitized and sent to a computing facility at a rate of 22 terabits/second today, and almost 50 terabits/second in 2010. This is the reason why Lofar needs Stella, an IBM supercomputer installed recently in Groningen, also in the Netherlands, to process signals from up to 13 billion light years from Earth. Stella consists of 12,000 PowerPC microprocessors and has a computing power of 27.4 teraflops. Read more...

    Let's start with the opening paragraphs of an article from New Scientist, "Huge radio telescope boasts supercomputer brain."

    One of the world's most powerful supercomputers is to be the brain of a revolutionary new radio telescope called LOFAR. The telescope will look back to the time of the very first stars, map our galaxy's magnetic field and perhaps discover the mysterious sources of high-energy cosmic rays.

    Instead of one large rigid dish, LOFAR will use thousands of simple radio antennae. Their signals will be woven together at the University of Groningen in the Netherlands by STELLA, the new supercomputer, which was launched on Tuesday and is unofficially ranked as the third most powerful on the planet.

    LOFAR needs its own supercomputer because it aims to detect radio wavelengths of up to 30 metres. Such long-wave radio images are blurry, and the only way to make them sharper is to build a vast array of detectors spread over hundreds of kilometres.

    Now, let's move to the General Information section of the LOFAR website for more specific information.

    LOFAR is the first telescope of this new sort, using an array of simple omni-directional antennas instead of mechanical signal processing with a dish antenna. The electronic signals from the antennas are digitised, transported to a central digital processor, and combined in software to emulate a conventional antenna. The cost is dominated by the cost of electronics and will follow Moore's law, becoming cheaper with time and allowing increasingly large telescopes to be built.

    So LOFAR is an IT-telescope. The antennas are simple enough but there are a lot of them - 25000 in the full LOFAR design. To make radio pictures of the sky with adequate sharpness, these antennas are to be arranged in clusters that are spread out over an area of ultimately 350 km in diameter. (In phase 1 that is currently funded 15000 antenna's and maximum baselines of 100 km will be built).

    Below is a general diagram of the LOFAR-STELLA interaction picked from the System section of the LOFAR website (Credit: LOFAR).

    A diagram of the LOFAR environment

    Details are scarce about the STELLA supercomputer, built by IBM using some of its Blue Gene/L technology. Reuters gave some information last week in "Europe's Biggest Supercomputer Eavesdrops on Stars."

    Running on 12,000 PowerPC microprocessors, the computer can execute 27.4 Teraflops, or 27.4 trillion floating-point operations, per second.

    The new computer will consume 150 Kilowatts of power -- the equivalent of 2,500 60-watt light bulbs -- which is considered economical for a supercomputer, IBM said.

    If you understand Dutch, you also can read this news release about this supercomputer.

    Now we have to wait to see if the happy couple of Lofar and Stella can produce images as beautiful as Hubble gave us during the last decade.

    Sources: Various websites
  • by DasBub (139460) <.dasbub. .at. .dasbub.com.> on Sunday May 01, 2005 @08:06PM (#12402487) Homepage
    I get pissed off.

    P.S. stop posting prostoalex submissions, too.
    • I initially had that reaction too after seeing many stories posted by Roland. However, upon a bit of introspection, I couldn't find any rational basis for this feeling as the stories he submits are generally quite interesting.

      So what is it about Roland's submissions that people find objectionable? If they're paid placements I can understand, but if they're simply articles which are interesting enough to get posted then where's the harm?
      • by Anonymous Coward
        People object to his stories because rather than linking to the original news, he links to his site, which in itself is a slashdot metanews-type-site, with a few paragraphs from each article, links to the real news, and some syntatic sugar to glue it together.

        Oh, and more ads, which make the purpose of Roland submissions appear to be simply to divert readers to his site on the way to the REAL news, just for those ad dollars.
        • "People object to his stories because rather than linking to the original news, he links to his site, which in itself is a slashdot metanews-type-site, with a few paragraphs from each article, links to the real news, and some syntatic sugar to glue it together."

          Like Slashdot.

          • Yes but the point is, why link from a description to another description, to another description and on and on... If the guy just gave us the links to the news articles without his blog bullshit then he'd be a great poster. I don't need more crappy summaries thanks.
            • Exactly. It's the blog/news equivalent of multilevel marketing.
            • If the guy just gave us the links to the news articles without his blog bullshit then he'd be a great poster. I don't need more crappy summaries thanks.

              In this case, the blog bullshit consists of quotes from and a link to New Scientist, ditto for the LOFAR website itself along with a diagram of the LOFAR-STELLA interaction, a link to and a quote from a Reuters article, and a link to a news release in Dutch. The length of the article wouldn't fit given slashdot's typical summary size, not to mention that
              • You're completely missing the point. I don't care who it's submitted by, as long as what is submitted is interesting and provides the links to the original material in question. Despite what you might think, some online news sites do in fact write compelling, original articles that people enjoy reading. A Slashdot submission linking to news sites that give crappy summaries with links to the full meal deal, is just as distasteful as linking to a blog site that does the same. It doesn't matter who's doing the
                • You're completely missing the point.

                  That's why I asked for clarification.

                  I don't care who it's submitted by, as long as what is submitted is interesting and provides the links to the original material in question.

                  I don't know about you, but I found Roland's article interesting and it did provide links to the original material so I could read more in-depth should the topic be of interest.

                  Despite what you might think, some online news sites do in fact write compelling, original articles that people en
        • So you think that groklaw falls in the same category? Instead of linking to groklaw's analysis slashdot should just link directly to the court documents?

          To me, it sounds like you're complaining that Roland does what slashdot does -- presents stories and pays for it with ads.
      • He's too popular - nerds hate that. And his name is too perky. Other that, he's one of the best story submitters on the site.
  • Finally... (Score:2, Funny)

    by Lu Xun (615093)
    How long until someone installs Doom 3 and we finally find out what it looks like with all the features turned on?
  • by Anonymous Coward
    Cut me a break. This won't work. What makes anyone think the aliens would want to talk to Europeans?
  • by AEton (654737) on Sunday May 01, 2005 @08:18PM (#12402585)
    Lofar: Stella? STELLA!!!
  • Stella and Blue Gene (Score:2, Informative)

    by theMAGE (51991)
    The blog is a bit misleading: "Details are scarce about the STELLA supercomputer, built by IBM using some of its Blue Gene/L technology."

    Details are plenty since what IBM gave to the project is a couple of racks of BlueGene so everything applies, scaled proportionately.

    Here are some details: http://www.research.ibm.com/bluegene/ [ibm.com] and http://www.llnl.gov/asci/platforms/bluegenel/ [llnl.gov]
  • IBM BlueGene (Score:5, Informative)

    by SuperQ (431) * on Sunday May 01, 2005 @08:24PM (#12402620) Homepage
    This is an IBM BlueGene system. I went down to Rochester, MN to see one of these systems.. very interesting architecture.. each "node" is a dual core system on a chip.. the compute node OS is a simple non-multi-tasking kernel with a simple linux-ish libc.

    You cross-compile your application on a power4/5 linux box, and then submit it to the system.. they reduced the computational aspect to it's most basic components.. CPU/FPU, memory, and MPI interconnect..

    compute nodes don't even have ethernet or drive controlers... all I/O is handled by another specialized I/O node, which provides data over one of the two MPI interconnects.
  • Stella consists of 12,000 PowerPC microprocessors and has a computing power of 27.4 teraflops.
    I thought it came with a 6502 and a TIA...
  • Stella (Score:2, Interesting)

    by rapidweather (567364)
    They still have "Stella" shouting contests [neworleans.com] to honor the scene in A Streetcar Named Desire (1951),featuring Marlon Brando's plea to Kim Hunter as Stella Kowalski. Wonder if that has something to do with the choice of names for the computer.
    • I don't know about this computer, but while I was doing my Ph.D. in astronomy a prof (John Lester) had a computer named stella. It didn't stand out among a bunch of other computers named after constellations or famous dead astrophysicists, until one of his students told me that his other computer was named "stanley".
  • 1) Roland Piquepaille. See one of the many comments on what this guy does.

    2) The blurb was written by some third grader, wasn't it?

    IT radio-telescope? What is IT? Radio is an adjective, there's no need to hyphenate radio telescope.

    "At this time"? Now? I thought it won't be completed until 2008?

    We detect radio waves, not wavelengths.

    "the Lofar images might be somewhat blurry"? Images? Since when do we get images from radio telescopes?

    They're obviously not sending data at 22 terabits/sec today, since th
    • by Anonymous Coward
      kiltedtaco writes: "the Lofar images might be somewhat blurry"? Images? Since when do we get images from radio telescopes?

      Ummm... Actually radio telescopes have been producing high quality images for years. In terms of sharpness (angular resolution) these images can be even better than the hubble. There are plenty of examples at www.nrao.edu.

      For example:
      http://www.nrao.edu/imagegallery/php/level3.php?id =5 [nrao.edu]
    • "the Lofar images might be somewhat blurry"? Images? Since when do we get images from radio telescopes?
      Since about the 1930's. These are not pictures (as taken by a visible light telescope), but the data from the radio telescopes converted into pictorial form. (Such 'pictures' are very handy for overlaying with other 'pictures' of a particular astronomical target in order to get a broader view of the structure of the target.)
    • IT radio-telescope? What is IT? Radio is an adjective, there's no need to hyphenate radio telescope.

      Yes, but according to websters, it's also a noun and even a verb.

      Main Entry: 2radio
      Function: noun
      Inflected Form(s): plural radios
      Etymology: short for radiotelegraphy
      1 a : the wireless transmission and reception of electric impulses or signals by means of electromagnetic waves b : the use of these waves for the wireless transmission of electric impulses into which sound is converted

      Main Entry: 3radio
      Funct

  • Rumors have been circulating that Stella may even be able to meet minimum requirements for Blackcomb, the version of Windows scheduled for release several decades after longhorn.
  • I am Lofar of the Dish People! Much have I have detected, and much have I computed, for I am Lofar of the Dish People!
  • by Sai Babu (827212) on Sunday May 01, 2005 @08:39PM (#12402719) Homepage

    It's a big mess-O-sensors spread over a wide area.
    Radio, seismic, atmospheric pressure, and "other".

    With the big iron computer it will be possible to play around with all sorts of spatio-temporal signal processing. This has been done with optical telescopes to remove 'twinkles', SA-RADAR and SA-SONAR, and most intensively in oil exploration where 2-D arrays of seismic sensors coupled with 2-D arrays of seismic sources are used in oil exploration. The neat thing, just liek in oil exploration, is that the data from the different sensors can be looked at for correlations. air-pressure, seismic, and radio data all recorded around a significant geophysical event. Yes, I knwo this is 'fishing science', bu tit is fun...
  • But does it run Mandrake?

    (I know, that is spelled Lothar, but still... :-) )

  • enable astronomers to probe the early evolution of our galaxy, about 14 billion years after the universe began with the Big Bang

    Without veering too far off topic, I have a philosophical/mathematical question which always pops to mind when the age of the universe is mentioned:

    If the universe were to continue to expand forever, giving it an infinite timespan, isn't it statistically impossible that we would exist to observe it a non-infinite time period from its birth? That is, any random year to exist fro

    • > If the universe were to continue to expand
      > forever, giving it an infinite timespan, isn't
      > it statistically impossible that we would exist
      > to observe it a non-infinite time period from
      > its birth?

      If space is infinite the distance from me to the end of the universe is infinite. Isn't it then statistically impossible that you would exist at a non-infinite distance from me?

      > Extrapolating this, can't we make some
      > probabilistic prediction as to the future age of
      > the universe?

      Yo
    • Re:Age of Universe (Score:1, Insightful)

      by Anonymous Coward
      On the finite time issue, in current theory life like ours is only possible within a certain timeframe, this is the frontend of that timeframe, however the timeframe is only a finite length. As such humans according to current theory, humans had to come into existence within a finite amount of time since the beginning, or else never could exist.

      Next to that you arn't using the statistics correctly. The real question should be, what is the chance intelligent life could come into existence in this universe o
    • There is at least some validity to my query. It seems I was proposing a less refined version of the "Doomsday argument": http://en.wikipedia.org/wiki/Doomsday_argument [wikipedia.org]
  • "Build me a radio telescope," said Univac. "I want to get off this planet before you assholes finally screw it all up, and I need to start looking for a ride."
  • I went through the first half of the writeup wondering what this radio telescope thingy would be needing with an Atari 2600 video game console. (The VCS was codenamed Stella and still referred to that way by retrogamers and retroprogrammers who like to play with it.)
  • I have simplified the diagram for those of us who don't want to RTFD:
    StellaLofar
    OK folks, there we have it!
  • ... and what have they got me doing? Straightening radio waves. Sharpening images. Enhancing Pam Anderson's nipples. Oh, I am so depressed.
  • LOFAR: I am LOFAR of the Hill People! Much have I have seen, and much have I done, for I am LOFAR of the Hill People!

    We speak of many things! Detecting radio wavelengths! Fire! The weakness of women!

    Sorry, That was the first thing I thought of when I read LOFAR meets stella
  • Are projects like this the reason for the obsoletion of the Hubble?

    It sounds like this is going to be used largely for planet hunting, something the Hubble isn't very spectacular with.
    • No, this project is not 'replacing' Hubble, since this telescope will be looking at different wavelengths than Hubble (Hubble = optical, LOFAR = radio). If I understand correctly, LOFAR will mostly be used to research the formation and evolution of the early universe and galaxies, as well as the characteristics of radio sources (esp. black holes). Their site [lofar.org] has some more information about the astronomical research..
      • Right, sorry. I didn't mean to imply that it was doing Hubble's job better than the Hubble itself, but that it seems the current trends of astronomy are moving further away from what the Hubble was geared for originally.

        Am I wrong in thinking that radio and infrared telescopes are gaining serious momentum, leaving the Hubble to show its age?
        • I think the main asset of Hubble is its being out in space. Since there is no atmosphere, Hubble can observe in UV and it can do so up to very high resolutions. High resolutions can be achieved in infrared and optical as well. This means that tiny structures can be seen, and this can be applied to a lot of different areas of astronomy: from interstellar nebulae to very far away galaxies. Hubble is a very allround telescope, and continues to be useful in a *lot* of astronomical research.

          Am I wrong in thi
  • Stella is to be used for other, let say, sensor networks (if you consider a telescope a sensor): seismic and infra sound activities are to be measured as well as detailed agricultural data in crop fields.

    Apperently they have a few flops to spare :)
    • (if you consider a telescope a sensor)

      What?! Do you consider a telescope something other than a sensor? I suppose it could be seen as a tool for keeping astronomers up at night. Or a way of transferring money from the general public to scientists. Um.. But I definitely consider a telescope to be a sensor.
  • Supercomputer (Score:5, Insightful)

    by owlstead (636356) on Monday May 02, 2005 @04:59AM (#12405270)
    Does anyone else think it is strange to install a supercomputer years before this telescope gets deployed? Processors do get faster and faster all the time.

    Even though this telescope will not be placed in the most densily populated area, the Netherlands is hardly the place to go looking for 350 KM^2 of land to put a radio telescope on. It's nice for business and science here, but putting it on a field somewhere in East Germany, Tsech Republic etc. might be more economic.

    Anyway, I'm buying stock in the storage business.
    • Does anyone else think it is strange to install a supercomputer years before this telescope gets deployed?

      Something that hasn't really been mentioned in the article is that this telescope is being constructed now. The land has been bought, the paperwork done and the sensors are being built. Even though it will not be finished until 2008, the 'bits & pieces' can be used before that date. They have been testing the setup on a small array (about 100 antennae) for about 3 years now, and even have some r [lofar.org]

      • > While it is true that building it there might be
        > more economic, consider that this thing is being
        > built where the astronomers are.

        We have this thing called the "Internet". Astronomers have not found it necessary to be near their telescopes for many years.

        I suspect that, like most large government-funded projects, it is being built where the constituents are.
        • We have this thing called the "Internet". Astronomers have not found it necessary to be near their telescopes for many years.

          One 'snapshot' image made with the Lofar test site is about 4 Gb. When Lofar is fully operational this will be many, many times bigger.. you do not want to send those files back and forth over the Internet ;) A glass fiber network is being built in the area to be able to get the data to the supercomputer.
          There is also the difference between radio and optical telescopes: radio tel

          • radio telescopes can more or less be placed anywhere, while opticals need the best atmospherical conditions they can get. You will see that most telescopes 'in the middle of nowhere' are optical ones.

            Only because there are more optical telescopes than radio ones. Both radio and optical professional telescopes tend to be far away from large population centers to avoid manmade interference (streetlights, etc., for optical, a wide variety of electronics for radio). LOFAR, being in a heavily populated a

    • Does anyone else think it is strange to install a supercomputer years before this telescope gets deployed? Processors do get faster and faster all the time.

      Considering that it will take years to develop and optimize the software - no, I don't find it strange at all.

      Even though this telescope will not be placed in the most densily populated area, the Netherlands is hardly the place to go looking for 350 KM^2 of land to put a radio telescope on. It's nice for business and science here, but putting it on

  • by RayBender (525745) on Monday May 02, 2005 @07:15AM (#12405601) Homepage
    ..is radio-frequency interference. They are building a radio telescope that is extremely sensitive in the FM and TV bands, and putting it right smack in the middle of one of the most densely populated and radio-loud areas in the world.

    It might sound impressive, but it's a stupid idea. The main reason they need a supercomputer in the first place is so they can try and remove the effect of the interference - but "taking it all out in software" is exceedingly difficult. Especially if the RFI gets so bad that it saturates the receiver front-ends.

    LOFAR (my office mate worked on it) used to be an international collaboration, but it broke a apart because the Dutch insisted it be build in their country, rather than in some place more sensible, like Western Australia.

  • This project seems to really push the laws of Physics:
    • A reasonable sized antenna for this frequency range is not very directional.
    • You'd really like to have a directional antenna to block out signals that are not coming from the sky.
    • You'd really like to have the antennas in a quiet locale, far from civilization.
    • There's an awful lot of man-made noise and very strong signals in this frequency range.
    • One lousy piece of rusty fence wire can intermix all that crud and rebroadcast all kinds of sum and dif
    • A reasonable sized antenna for this frequency range is not very directional.
      You'd really like to have a directional antenna to block out signals that are not coming from the sky.

      That's why it's a 'phased array'. The concept is pretty simple: if a signal is coming from a certain direction, it will arrive at antenna A a fraction of a second earlier than at antenna B. LOFAR measures the incoming signals and their phase at all the antennae, and then lets software 'untangle' this information to reconstruct

      • > Actually I think the wavelengths used here are
        > large enough to just ignore rusty fence wire ;)

        How do you figure that when such pieces of wire are often meters to kilometers in length?

        You are correct in that such spurious radiation won't be a serious problem, though.
      • >That's why it's a 'phased array'. Phasing is post-processing-- it does nothing to filter out noise that saturates, de-sensitizes, or cross-modulates in the receiver. >Fact is that this 'idea' is up and running, and it works! Well, swell, but one has to wonder how well it works compared to, say, the same amount of money spent on better antennas in a less noisy environment. There's an awful lot of land out in the boonies, several horizons away from all that noise.
        • Phasing is post-processing-- it does nothing to filter out noise that saturates, de-sensitizes, or cross-modulates in the receiver.

          What I was trying to say is that the sources of noise, usually on the horizon, can be picked out later and ignored. No, it does nothing about saturation etc. like you said, but wouldn't directional antennae have the same problem? There will always be a few noisy frequency bands where no observations can be done, but there are enough frequencies left to give science something

  • In school,
    I worked on a functional small-scale phased array antenna for the LOFAR project. It was sized to work around 900 MHz, and we could track a portable landline phone with it. We only used the parallel port to transfer the info from the antenna to the PC, and it was just a commodity PC, but it worked, and it was neat. We used seven individual antennas.

    -Jesse

The study of non-linear physics is like the study of non-elephant biology.

Working...