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Communications Network Science

No Wi-Fi Around Huge Radio Telescope 224

JG0LD writes "Students at a tiny Appalachian public school can't use Wi-Fi because any such network can throw the radio equivalent of a monkey wrench into a gigantic super-sensitive radio telescope just up the road. GBT's extraordinary sensitivity means that it's very susceptible to human-generated radio interference, according to site interference protection engineer Carla Beaudet. 'If there was no dirt between us and the transmitter, a typical access point ... would have to be on the order of 1,000,000 km [more than 620,000 miles, or about two and a half times the distance from the Earth to the Moon] distant to not interfere. Fortunately, we have mountains around us which provide lots of attenuation, so we're not seeing everything from everywhere,' she said. A standard Wi-Fi access point would wipe out a significant range of usable frequencies for the observatory. 'It simply ruins the spectrum for observations from 2400-2483.5MHz and from 5725-5875MHz for observational purposes,' wrote Beaudet."
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No Wi-Fi Around Huge Radio Telescope

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  • This is news? (Score:5, Informative)

    by dtmos ( 447842 ) * on Friday February 08, 2013 @08:07PM (#42839177)

    The National Radio Quiet Zone has been there since 1958 [nrao.edu]. It's not like it was just discovered yesterday. People living in this zone have always had to live without radio transmitters. Not having 802.11 is just another of the services they cannot use, like wireless garage-door openers and cell phones.

    • by LWATCDR ( 28044 )

      Maybe they could build a Faraday fence between the school and the radio telescopes. Of course the wack jobs that claim to be em sensitive love this place.

    • Re:This is news? (Score:5, Interesting)

      by Sipper ( 462582 ) on Friday February 08, 2013 @09:22PM (#42839771)

      I've visited the GBT while it was under construction at the NRAO; there's another interesting feature of the site due to the location being surrounded by mountains -- which is that thunder from lightning strikes take a long time to dissipate, because they reverberate between the mountains. It's reallly something to listen to -- the rumble after the initial thunderclap lasts for about 20 to 30 seconds. :-) Somehow it's like a symphony to the soul.

    • please tell me what civilian devices operated at 2GHz+ in 1958

      • please tell me what civilian devices operated at 2GHz+ in 1958

        Microwave ovens.

        • please tell me what civilian devices operated at 2GHz+ in 1958

          Microwave ovens.

          Long-distance microwave telephone replays (AT&T)?

          Commercial airliner radar domes?

    • Ah that's where it is, I was just about to say "whoever got there second was dumb to build there and is causing the problem."

      You'd figure that as an international sanctuary for the "radio-sensitive" nutbags, there would be no trouble selling real estate and moving away.

  • This is also a huge problem for spaceborne radiometers that observe the Earth's surface ( example paper [usna.edu]). A radiometer is essentially a very sensitive receiver, and there are portions of the UHF and microwave spectrum reserved specifically for scientific research so that terrestrial stations don't interfere with the measurements. Unfortunately, interference may occur from transmitters directly in the band, from adjacent channels, or inadvertent harmonics from poorly-filtered transmitters. Pinpointing and cor
  • What ever happened to that wifi blocking wallpaper?

    • That won't do enough. It's like the difference between trying to shock-proof a cd player and trying to shock-proof a seismometer. You need a whole new LEVEL of filtering.
  • by pesho ( 843750 ) on Friday February 08, 2013 @08:27PM (#42839333)
    NSF plans to cut the funding [sciencemag.org] for the National Radio Astronomy Observatory at Green Bank. So I guess the kids will soon have WiFi and cell phones. This is a good thing, right?
    • by Anonymous Coward on Friday February 08, 2013 @09:02PM (#42839653)

      NRAO Green Bank has several telescopes, a few of which are funded by organizations other than NRAO. Most notably, the 140 foot dish is currently funded by a project from MIT. There are also many other educational program that run at Green Bank that are not the GBT or VLBA, such as the small 40 foot dish which is available for school trips & amateur astronmers. The article is not clear about the fate of these other programs at NRAO Green Bank.

      I grew up in West Virginia, and took a trip to Green Bank in 8th grade where our teacher had reserved time for us on the 40 foot dish. We were allowed into the control room, and were instructed on how to aim the dish at a celestial object that was in view during our visit. And that was separate from the liquid nitogren demonstration they had for us as well. For the most part, Green Bank is looked upon favorably by those in the community around it.

      If you want to get to odd rules about NRAO Green Brank, how about the fact that there is a keep-out zone for standard gasoline engines near the 'scopes. Only diesel vehicles may be used on the observatory's grounds, due to radio emissions from spark plugs.

  • Why is anyone even making an issue of this?

  • The article doesn't explain why the tablet computers must have a network connection to be used to read digital textbooks. Is there any reason why the digital textbooks can't be loaded from a hardwired connection and then used when the tablets are offline?

    The article also doesn't explain why every student in the entire school must have simultaneous internet access in order to take the online standardized tests. It should be possible to set a computer lab with enough computers to allow every student in a single grade to take the online standardized tests.

    The article mentions that there is a highly restricted NSA facility near the school. I'm sure that the NSA knows how to limit signal leakage and radio frequency interference. Perhaps the NSA facility can find a solution to this problem that doesn't require a wireless network.

    • Is there any reason why the digital textbooks can't be loaded from a hardwired connection and then used when the tablets are offline?

      Because iPads don't have USB ports, ethernet ports, or any sort of removable storage whatsoever.

      The only way to get those books onto the tablets would be to pack all of them into a car, drive to someplace far enough away that they CAN use wifi, and manually load the books onto each tablet one at a time.

      • So don't use ipads they are a walled garden to begin with.

      • by aheath ( 628369 ) *

        1 - The original article doesn't mention the make and model of the tablet computers that the Pocohantas County schools are planning to use for electronic textbooks. It's possible that they will select Android over iOs

        2 - iPads have either a 30-pin to USB connector or a Lightning to USB connector. The wired connection can be used to transfer files to and from the iPad.

        • It's possible that they will select Android over iOs

          Mod +5 funny.

          Sorry but Androids aren't as sexy as iPads, and unless the principle and members of the schoolboard own Android tablets you're going to see yet another worthless waste of money in the school system rolling out devices with limited functionality in an attempt "improve school".

      • iPads don't have USB ports

        Of course it does, and both [apple.com] genders [iphoneshop.net] at that.

        or any sort of removable storage whatsoever

        Come again [apple.com]?

        • I have the camera connection kit for the ipad. It's not as useful as it might seem.

          I'm a clumsy oaf, so my ipad tends to live in one of those griffin survivor cases (which really are tough, but the screen is less than lovely). As a result, the port is blocked, since griffin, in their less than infinite wisdom, based the 30 pin opening on the charger cable, Now, I could get one of those 30 pin extension cables, but every once in a while someone will remind you, in a negative review, that only the charging p

      • Tee hee. My iPhone has a USB connection and an app called Files that lets me put PDF files on it via the charging/sync cable.

        I suspect that an iPad has the same capability, as it runs the same software.
      • by guruevi ( 827432 )

        They have at least a USB port to be charging and syncing and you can buy external flash drives for them. Apple sells entire classroom solutions through their EDU reps.

  • by phizi0n ( 1237812 ) on Friday February 08, 2013 @09:28PM (#42839811)

    The summary is restating the obvious but the actual article is about how the school district and state are moving to use ebooks and online testing so this school needs a lot of additional networking gear to keep everything wired only. They also mention how 802.11ad would work since it's signal range is too high to get through the atmosphere so the observatory doesn't care about it, but 802.11ad isn't readily available yet.

  • Lunar telescopes (Score:5, Interesting)

    by Areyoukiddingme ( 1289470 ) on Friday February 08, 2013 @09:42PM (#42839933)

    This is why the proposal to build a radio telescope array on the far side of the Moon has been around for so long. Having the moon between us and it is one helluva lot of dirt for blocking stray signals. Plus no atmosphere to get in the way. All you have to worry about then is reflection of Earthly signals off of other bodies in the solar system.

    Too bad about the expense...

  • by omarius ( 52253 ) <omar&allwrong,com> on Friday February 08, 2013 @10:00PM (#42840089) Homepage Journal
    This is the second post I've seen in as many days on Green Bank, and no mention of the fact that the NSF is planning on closing the facility to save money. Green Bank is the largest movable radio telescope in the world. If you feel--like I do--that this would be a detriment to the nation, please sign the petition [change.org] or, even better, write your Congressperson.
  • Your better off running a wire network in the first place. I may be wrong ( which I'm not ) but couldn't you just put the school in a magnetic cage so to speak there for blocking it from giving off / taking unwanted fields.
  • So many devices come with 802.11? and Bluetooth, it's not possible to control or police it. Some laptops have hardware switches for wireless, some have software swithches (thanks to airplane regulations), but many just leave it running. There's a lot of things which operate in the 2.4 GHz band, which the residents will not even think about, even if they are well-meaning and diligent. Thermostats, weather stations, cordless phones are some examples.

    On the other hand, this place would be a haven for those peo

    • by mpe ( 36238 )
      Some laptops have hardware switches for wireless, some have software swithches (thanks to airplane regulations), but many just leave it running.

      In many cases laptops come with wireless on a separate card. Which can be removed/not fitted in the first place.
  • They should have built the telescope on the back side moon if they wanted quiet.

  • I'm detecting a bit of a red herring in the article. Seems that the school is complaining about the cost of the required laptops in addition to the cost of the cat5 drops in the school rooms due to the shift to digital text books.

    The cost of the laptops would have to be spent regardless of the school's location due to the shift to digital text books, so the only "additional" cost would be that of the cat5 drops in each room. However, the following quote from the article:

    Green Bank Elementary/Middle has a strong and long-standing relationship with the scientific facility up the road - the NRAO installed Cat-5 cable throughout the school years ago, and Beaudet says the organization provides as much support as possible.

    Rather strongly implies that the scho

  • There's a WiFi transmitter within 100 miles of that dish, with nothing but plain air separating, at least 14 hours a day.

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