350 KM Diameter Radio Telescope Array

photonic writes "Yesterday the Dutch government awarded a 52 Million Euro grant (press release in Dutch) to the Lofar, or Low Frequency Array telescope. Instead of traditional single large disk, the telescope will consist of 25000 small base stations, which are each not much more than small omni-directional antennas. Together they will be used as a phased array with enormous resolution. The base stations will be spread out across the northern part of the Netherlands, Denmark and Germany. Eventually, the telescope will be part of an international collaboration, with additional arrays planned by MIT and in Australia. There are also plans to add more sensors to the base stations to form a distributed network for monitoring weather, earthquakes and the like. The array should be finished in 2006 and will cost around 150 MEuro total. The telescope will also be very interesting from an IT point of view: Dedicated fiber optical cables will be needed for the enormous amount of data transport (Tera-bits/second). This was actually used as a big selling point, because some rural areas will get fast internet access as an aside. There are contacts with IBM to use one of their future Blue Gene supercomputers for the central data processing. An English brochure is available with more details."

Article link...

[hookedup]

A real link [ibm.com]

"lofar"?

[hitzroth]

Shouldn't that be "Low FAT"?

Re:"lofar"?

[justanyone]

For the uninitiated, there was a James Bond villan (an asian one) named, "Lo Fat". I'm not sure which movie it was, though. I can't find it on any of the lists... Maybe it was Austin Powers instead.

How far does it scale up?

[Urkki]

If we covered entire surface (both land and sea) of Earth with this kind of array, what could we see (or "hear" maybe) with it?

Would that have (theoretically) enough resolution to for example get decent resolution radio-frequency images of surfaces of nearby stars?

Or could we use it as a radar, sweeping the solar system and locating every asteroid hurling about, and calculate their orbits for potential collision with Earth?

Now all we need is a couple of fusion reactors providing enough power to use such

Re:How far does it scale up?

[photonic]

Note that resolution gets better with a bigger array size, but gets worse with bigger wavelength (or lower frequency).

Assuming a frequency of 100MHz, the resolution of LoFAr would be equivalent with a (350km * 100e6Hz / 5e14Hz =) 7 cm optical telescope or a 70 cm telescope when operating at 1 GHz. Although not much compared to Hubble or Keck, this would probably give some nice images.

Re:How far does it scale up?

[JohnPM]

probably give some nice images?!

You don't get 100 million euro devices built for the sake of some nice images. They're selling it on the idea of answering some of the fundamental questions about the universe. Like where do the high-energy cosmic rays come from? These are single protons with the energy of a driven golf ball and cannot be explained by current cosmology.

Also interesting to note is that they are planning to use the massive data network required to monitor other things like weather and seismic

Re:How far does it scale up?

[xluap]

The frequency is 10MHz to 240MHz.

Here is a link to a detailed pdf aboutlofar [lofar.nl]

International Collaboration?

[tiled_rainbows]

Whaddaya mean, "eventually" it will become an international collaboration? You do know that Denmark, Holland, and Germany are differnt countries, right?

Although I have to admit that "collaboration" is an unfortunate word to choose when you're talking about those particular countries working together.

Re:International Collaboration?

[Urkki]

Are you sure those 3 countries are actually working together on it? I get the impression it's actually a Dutch project, they're just going to use the area of the two other countries as well for the array.

I could be wrong though.

What the world needs...

[bhima]

Is a way to convert old satellite dishes into satellite radio receivers so we can do the SETI equivalent in data gathering

Re:What the world needs...

[Leroy_Brown242]

This is an Ecellent idea!

I can imagine some geeks with some land setting up 20 or so of these dishes up in thier back yard. Geeks cover the globe, and geeks would find this interesting. No need for finding places to put dishes, because private citizens would be doing it of thier own free will on thier own land.

Re:What the world needs...

[Nynaeve]

That's exactly what Array2k [setileague.org] is.

limiting factor

[LordMyren]

i cant imagine how they're imaging creating any sort of absolute metric for time. i suppose if its low frequency enough its not that problematic.

Metric of time

[Ex-MislTech]

In Telecommunications time sync is achieved via Stratum Clocks
that are typically sync'd via Satellite links .

The accuracy of military GPS is partially based on this method .

Here is an example of one that is commercially made and not as
accurate a is feasibly possible :

http://www.endruntechnologies.com/time-server.ht m

Peace,
Ex-MislTech

How does one volunteer?

[kulakovich]

If you are in the New England region of the US, how can you volunteer to host an array? kulakovich