Slashdot Mirror

Chang'e 4 will also carry an experimental radio-astronomy receiver on its relay satellite, more here.

Here is a presentation by Pim Schellaert (referenced in the article) with some more information:
http://www.lofar.org/wiki/lib/...

I've seen a presentation of their more recent results, but that doesn't seem to be public yet, I can't find a link.

One of the coolest things we did recently with the LOFAR telescope was to observe the Solar Eclipse in real time, I think it has never been done with a radio telescope before: https://www.youtube.com/watch?...

In general you can find a lot of info about what we're doing with the LOFAR telescope here:
http://www.astron.nl/dailyimag...
and here: http://www.lofar.org/wiki/doku...

This type of reuse of ex-military kit quite often happens, although not normally so long after it was originally used. I'm not sure if it's still running on the same engines but I know that the Lovell Radio Telescope at Jodrell Bank (UK), at one time the largest movable dish telescope, originally had a lot of parts cannibalised from engines taken from two battleships. Lovell, the maker of the telescope, had also previously been using quite a lot of reclaimed military kit for his astronomical observations before the actual radio telescope was built.

After WWII German Würzburg 'Riese' GCI radar antennas were repurposed for radio astronomy. Some of them remained in use at least into the 1980s. I wonder if any are still in use?

http://en.wikipedia.org/wiki/Würzburg_radar
http://www.astron.nl/~leeuwen/video/dloo/JAHH9p3.pdf

While I think ALMA is a really cool project, but I don't think it's got the largest collecting area either. I'm assuming that's what you mean, otherwise I'm not sure what you mean.

ALMA has a collecting area of about 7,000 m2. LOFAR has a collecting area of up to to 300,000 m2, depending on the frequency and antenna configuration used.
http://www.astron.nl/radio-observatory/astronomers/technical-information/lofar-technical-information

But yeah, there are multiple ways to claim the title "Largest Telescope". Things get really funny with VLBI and space based VLBI.

Well, that's partially true. The online/realtime processing doesn't store the data. We have the data coming in at about 150 Gbit/s into the BlueGene supercomputer (34 TFlop), which does initial realtime processing and writes resulting files at about 50 Gbit/s on a roughly 1 Petabyte intermediate storage system for offline processing. From there it gets initial processing/calibration and a factor of 16 to 64 reduction in size on the offline processing cluster (about 200 8core machines). Also some inspection of the data is done for quality assessment, and sky images are made. If the quality is good, the resulting data and images are moved to out 4+ Petabyte long term archive, where further processing can also be done to achieve publication ready results.
On average we are expected to be producing about 20 TB/hour raw data, and about 700 GB/hour data that gets archived (life time of more than a week).

As I speak we are 2 weeks away from the system being opened by the Dutch Queen, and we are operating on about half the above numbers with about 25 antenna fields online. By the end of 2010 we should be operating at full strength. Also, those numbers are from the top of my head, so I might be off a bit here and there.

LOFAR is seen as a precursor to SKA, the first of a new generation of telescopes based much more on software and firmware and cheap off the shelve instead of expensive dishes and custom DSP hardware. After the various VLBI efforts (Including JIVE, which is housed in the same building as ASTRON and LOFAR), LOFAR now is the biggest telescope on Earth.
http://www.astron.nl/dailyimage/main.php?date=20100421
http://www.astron.nl/dailyimage/main.php?date=20100125

There are some rather nice images starting to come out of the system, if you're a radioastronomer, but most are under embargo until the opening. I can show you this older image:
http://www.astron.nl/dailyimage/main.php?date=20100208

When mentioning SKA precursors, it's also noteworthy to mention that the 14 25meter dish WSRT array will be upgraded with focal plane arrays over the next two years, and the EMBRACE test bed has almost finished building it's first three stations.
http://www.astron.nl/dailyimage/main.php?date=20070801
http://www.astron.nl/dailyimage/main.php?date=20091012

Well, that's partially true. The online/realtime processing doesn't store the data. We have the data coming in at about 150 Gbit/s into the BlueGene supercomputer (34 TFlop), which does initial realtime processing and writes resulting files at about 50 Gbit/s on a roughly 1 Petabyte intermediate storage system for offline processing. From there it gets initial processing/calibration and a factor of 16 to 64 reduction in size on the offline processing cluster (about 200 8core machines). Also some inspection of the data is done for quality assessment, and sky images are made. If the quality is good, the resulting data and images are moved to out 4+ Petabyte long term archive, where further processing can also be done to achieve publication ready results.
On average we are expected to be producing about 20 TB/hour raw data, and about 700 GB/hour data that gets archived (life time of more than a week).

As I speak we are 2 weeks away from the system being opened by the Dutch Queen, and we are operating on about half the above numbers with about 25 antenna fields online. By the end of 2010 we should be operating at full strength. Also, those numbers are from the top of my head, so I might be off a bit here and there.

LOFAR is seen as a precursor to SKA, the first of a new generation of telescopes based much more on software and firmware and cheap off the shelve instead of expensive dishes and custom DSP hardware. After the various VLBI efforts (Including JIVE, which is housed in the same building as ASTRON and LOFAR), LOFAR now is the biggest telescope on Earth.
http://www.astron.nl/dailyimage/main.php?date=20100421
http://www.astron.nl/dailyimage/main.php?date=20100125

There are some rather nice images starting to come out of the system, if you're a radioastronomer, but most are under embargo until the opening. I can show you this older image:
http://www.astron.nl/dailyimage/main.php?date=20100208

When mentioning SKA precursors, it's also noteworthy to mention that the 14 25meter dish WSRT array will be upgraded with focal plane arrays over the next two years, and the EMBRACE test bed has almost finished building it's first three stations.
http://www.astron.nl/dailyimage/main.php?date=20070801
http://www.astron.nl/dailyimage/main.php?date=20091012

Well, that's partially true. The online/realtime processing doesn't store the data. We have the data coming in at about 150 Gbit/s into the BlueGene supercomputer (34 TFlop), which does initial realtime processing and writes resulting files at about 50 Gbit/s on a roughly 1 Petabyte intermediate storage system for offline processing. From there it gets initial processing/calibration and a factor of 16 to 64 reduction in size on the offline processing cluster (about 200 8core machines). Also some inspection of the data is done for quality assessment, and sky images are made. If the quality is good, the resulting data and images are moved to out 4+ Petabyte long term archive, where further processing can also be done to achieve publication ready results.
On average we are expected to be producing about 20 TB/hour raw data, and about 700 GB/hour data that gets archived (life time of more than a week).

As I speak we are 2 weeks away from the system being opened by the Dutch Queen, and we are operating on about half the above numbers with about 25 antenna fields online. By the end of 2010 we should be operating at full strength. Also, those numbers are from the top of my head, so I might be off a bit here and there.

LOFAR is seen as a precursor to SKA, the first of a new generation of telescopes based much more on software and firmware and cheap off the shelve instead of expensive dishes and custom DSP hardware. After the various VLBI efforts (Including JIVE, which is housed in the same building as ASTRON and LOFAR), LOFAR now is the biggest telescope on Earth.
http://www.astron.nl/dailyimage/main.php?date=20100421
http://www.astron.nl/dailyimage/main.php?date=20100125

There are some rather nice images starting to come out of the system, if you're a radioastronomer, but most are under embargo until the opening. I can show you this older image:
http://www.astron.nl/dailyimage/main.php?date=20100208

When mentioning SKA precursors, it's also noteworthy to mention that the 14 25meter dish WSRT array will be upgraded with focal plane arrays over the next two years, and the EMBRACE test bed has almost finished building it's first three stations.
http://www.astron.nl/dailyimage/main.php?date=20070801
http://www.astron.nl/dailyimage/main.php?date=20091012

Well, that's partially true. The online/realtime processing doesn't store the data. We have the data coming in at about 150 Gbit/s into the BlueGene supercomputer (34 TFlop), which does initial realtime processing and writes resulting files at about 50 Gbit/s on a roughly 1 Petabyte intermediate storage system for offline processing. From there it gets initial processing/calibration and a factor of 16 to 64 reduction in size on the offline processing cluster (about 200 8core machines). Also some inspection of the data is done for quality assessment, and sky images are made. If the quality is good, the resulting data and images are moved to out 4+ Petabyte long term archive, where further processing can also be done to achieve publication ready results.
On average we are expected to be producing about 20 TB/hour raw data, and about 700 GB/hour data that gets archived (life time of more than a week).

As I speak we are 2 weeks away from the system being opened by the Dutch Queen, and we are operating on about half the above numbers with about 25 antenna fields online. By the end of 2010 we should be operating at full strength. Also, those numbers are from the top of my head, so I might be off a bit here and there.

LOFAR is seen as a precursor to SKA, the first of a new generation of telescopes based much more on software and firmware and cheap off the shelve instead of expensive dishes and custom DSP hardware. After the various VLBI efforts (Including JIVE, which is housed in the same building as ASTRON and LOFAR), LOFAR now is the biggest telescope on Earth.
http://www.astron.nl/dailyimage/main.php?date=20100421
http://www.astron.nl/dailyimage/main.php?date=20100125

There are some rather nice images starting to come out of the system, if you're a radioastronomer, but most are under embargo until the opening. I can show you this older image:
http://www.astron.nl/dailyimage/main.php?date=20100208

When mentioning SKA precursors, it's also noteworthy to mention that the 14 25meter dish WSRT array will be upgraded with focal plane arrays over the next two years, and the EMBRACE test bed has almost finished building it's first three stations.
http://www.astron.nl/dailyimage/main.php?date=20070801
http://www.astron.nl/dailyimage/main.php?date=20091012

Well, that's partially true. The online/realtime processing doesn't store the data. We have the data coming in at about 150 Gbit/s into the BlueGene supercomputer (34 TFlop), which does initial realtime processing and writes resulting files at about 50 Gbit/s on a roughly 1 Petabyte intermediate storage system for offline processing. From there it gets initial processing/calibration and a factor of 16 to 64 reduction in size on the offline processing cluster (about 200 8core machines). Also some inspection of the data is done for quality assessment, and sky images are made. If the quality is good, the resulting data and images are moved to out 4+ Petabyte long term archive, where further processing can also be done to achieve publication ready results.
On average we are expected to be producing about 20 TB/hour raw data, and about 700 GB/hour data that gets archived (life time of more than a week).

As I speak we are 2 weeks away from the system being opened by the Dutch Queen, and we are operating on about half the above numbers with about 25 antenna fields online. By the end of 2010 we should be operating at full strength. Also, those numbers are from the top of my head, so I might be off a bit here and there.

LOFAR is seen as a precursor to SKA, the first of a new generation of telescopes based much more on software and firmware and cheap off the shelve instead of expensive dishes and custom DSP hardware. After the various VLBI efforts (Including JIVE, which is housed in the same building as ASTRON and LOFAR), LOFAR now is the biggest telescope on Earth.
http://www.astron.nl/dailyimage/main.php?date=20100421
http://www.astron.nl/dailyimage/main.php?date=20100125

There are some rather nice images starting to come out of the system, if you're a radioastronomer, but most are under embargo until the opening. I can show you this older image:
http://www.astron.nl/dailyimage/main.php?date=20100208

When mentioning SKA precursors, it's also noteworthy to mention that the 14 25meter dish WSRT array will be upgraded with focal plane arrays over the next two years, and the EMBRACE test bed has almost finished building it's first three stations.
http://www.astron.nl/dailyimage/main.php?date=20070801
http://www.astron.nl/dailyimage/main.php?date=20091012

Here is a map: http://www.astron.nl/~heald/lofarStatusMap.html

We've been doing radio-interferometry already quite a bit longer, I work at the WSRT, which became operational in 1970.
http://www.astron.nl/p/WSRT2.htm

From http://www.aoc.nrao.edu/~cwalker/talks/aaas_2001/tsld007.htm, it looks like VLBI is already 40 years old.
        * 1967 First VLBI
                    o Jan: U. Florida - 1 kHz on Jupiter bursts
                    o Apr: Canadian group 448 MHz, 1 MHz bw
                    o May: NRAO-Cornell 610 MHz, 360 kHz bw
                    o June: MIT-NRAO-Cornell OH masers

        * 1968 Jan. First multi-station observations
                    o Already global - includes Onsala, Sweden

        * 1969 Oct. First US/USSR observations

No, just before they used tapes (VLBA), or harddisk packs (EVN), so instantantious is in comparison with shipping the data with UPS and having to wait a week for it to arrive.

See http://www.jive.nl/ [www.jive.nl] for all the details and http://www.astron.nl/dailyimage/main.php?date=2007 0906 [astron.nl] for some images.

The big difference with how the VLBA operates and how the EVN (european VLBI network) operates, is that this was done in real time, so called e-VLBI. No tapes, no harddisk packs, but live lightpaths across the globe.

See http://www.jive.nl/ for all the details and http://www.astron.nl/dailyimage/main.php?date=2007 0906 for some images.

How about:

http://www.lofar.org/
http://www.astron.nl/p/lofarframe.htm

What do you mean? It is already an FCC regulated frequency. According to ITU rules, the frequencies they are listening to" are already allocated to radio astronomy as primary. You cannot legally operate in these frequencies unless you also have primary allocation. They are reserved for science and some other specific tasks.

Yes. See FCC ruling. One of such radars
I believe the issue of opening up this frequency for automotive use is currently being debated in Europe, too.
There are protected bands around 23.7 GHz for ammonia spectral lines.See this list.

I use this.