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Building A Global Network Of Open Source SDR Receivers (jks.com)
hamster_nz writes: A fellow Kiwi is attempting to crowdfund a world-wide network of open-source, software-defined, radio receivers. Once in place, this will allow anybody anywhere in the world to scan the 0 to 30MHz RF spectrum from the comfort of their HTML-5 web browser. Built on top of the Beaglebone, the "KiwiSDR" RF board also includes a GPS receiver front-end, which will allow timing between receivers to be correlated, giving a lot of options for projects like long baseline interferometry and lightning detection. Prototypes are already deployed, and I've been RXing in Sweden, Australia and New Zealand. [The KiwiSDR design has been detailed on JKS.com, where there is a link to the project's Kickstarter page.]
I remember admiring all of the TV antennas while I was in Europe and thinking how cool it would be to build a giant array of RTL-SDRs hooked up to the damn things, then networked using some sort of Bittorrent/Tor like network which allows reciever time to be purchased by the hour via bitcoin payments.
The problem is the narrow frequency response of antennas. It's not an easy problem to correct for digitally(even if you have many measurements spread out geographically).
You might be able to measure an individual antennas frequency response by using two other antennas in the same geographic proximity. It will be difficult to distinguish between environmental attenuation and low signal gain. DSP is pretty amazing. I look forward to seeing what people dream up. A giant passive radar array would be pretty spiffy!
The link in the summary is in the process of being slashdotted... Here is the link to the Kickstarter page:
https://www.kickstarter.com/pr...
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Now we're crowdfunding a world wide surveillance network.
This is funny considering such a receiver is illegal in certain countries like Germany, France and Saudi Arabia, a new challenge to their overlords :)
Over here in The Netherlands it is no problem as our freedom of expression goes a little wider, it includes freedom of information.
"The likes of Facebook and WhatsApp are free to those whose privacy is of zero value."
Freedom to receive whatever is in the air is one thing. Freedom to spread what you find far and wide is another, and may well not be included.
Wow, it's a bit pricey for the first tier to actually get one. Still it would give that beaglebone black I have a use other than sitting on the desk.
Do not look at laser with remaining good eye.
The RTL-SDR unit is roughly $25. $200 is way over-priced.
http://www.rtl-sdr.com/
If the NSA did this, the listening would be done by a small cadre of unknown people with no data being shared publicly, especially if something interesting is found. Think about how Unternet access to freely available satellite imagery has changed how we look at and understand the world, both natural and man made. The tools are already in use by the few, secretly. This puts more of us on a slightly more equal footing.
Great article except for one thing: I am not enough of a dweeb to know what SDR means in this context! With so many acronyms out there, could we ask that slashdot posts include an initial explanation of the acronym followed by its use in the lines that follow?
Plenty of things below 30MHz worth listening to.
Ham Radio guys of all sorts in all sorts of frequencies
Aircraft and marine radios
CB Radios
Many radio stations operate below 30MHz depending on what part of the world you are in (especially AM radio)
Broadcasting on the shortwaves is rapidly dying, and everything that can be heard there is available on internet with much better quality. Ham radio chit-chat on shortwaves is just plain boring, and the remaining stuff isn't intended to be listened (i.e. it is strongly encrypted). I really wonder why they are so eager to crowdfund this project.
North Korean ICBM launch codes have been known to be transmitted in the clear betweeen 15-50 MHz.
Didn't someone try this before and fail? They built a bunch of receivers and hooked them up to the internet so that folks could tune in to television broadcasts they normally could not receive. The Supreme Court of the United States ruled against them.
When our name is on the back of your car, we're behind you all the way!
Like that?
http://websdr.org/
Actually this KiwiSDR project covers the entire range up to 30MHz, the WebSDR receivers usually only cover bands except for the one in Enschede. If you have limited dynamic range the narrowband approach might be a good idea, lets see how the KiwiSDR is going about all this. Ultimately I hope the projects can merge somehow.
Aw shucks:
"Unfortunately, it looks like I may not be able to obtain a license to use the WebSDR code, which is currently closed-source. So for now this part of the project is just a demonstration. I am however working on an open-source alternative."
from the Kiwi website: http://www.jks.com/KiwiSDR/
Well KiwiSDR is the way to go then.
Je me souviens.
North Korean ICBM launch codes have been known to be transmitted in the clear betweeen 15-50 MHz.
Yeah, but everyone already knows what they both are, now.
For your security, this post has been encrypted with ROT-13, twice.
f the NSA did this, the listening would be done by a small cadre of unknown people with no data being shared publicly
Sure, for Intel that only has significance militarily; but for all the rest?? "Parallel reconstruction" is just the start; it's only a matter of time until TPTB find other ways to monetize that data (think stock manipulation, data shared with competing businesses, etc, etc).
North Korean ICBM launch codes have been known to be transmitted in the clear betweeen 15-50 MHz.
I havevit on good authority that Somalian starship launch codes are also broadcast on a fairly low frequency... (and apparently aren't being received, either).
There are a number of existing ham radios already connected to the Internet. Here's an android app you can use to connect and tune the frequencies.
https://play.google.com/store/apps/details?id=org.v1al&hl=en
I guess the benefit of this project is to make a simple device users and buy install into their network to expand the number of servers.
you can choose a bunch from here http://websdr.org/
but the best one is here http://websdr.ewi.utwente.nl:8...
Sorry, teleporters just kill you and then make a copy. A perfect, soul-less copy.
For my money, RTL-SDR with an HF downconverter is a better bang for the buck, but less than 3 MHz of the spectrum is available at one time depending on the USB speed you choose (here's hoping for USB 3.0 RTL-SDR some day).
The Kiwi will do the entire 30 MHz if the screen shots on the Kickstarter site are correct, for 3x the price, or 4x the price if you want the $100 enclosure. Seriously, a $100 enclosure.
Then there's this custom job that can monitor and record the entire 30 MHz spectrum at once:
http://websdr.ewi.utwente.nl:8...
Kriston
Hams have been doing this for decades.
Hello all,
I thought I'd make it apparent that there is already a site that does this, sort of:
websdr.org
The RBN has been around since 2009. Software defined radios (SDRs) operated by hams and SWLs in over 100 locations worldwide listen to the HF and low VHF ham bands, decode the CW, radio teletype and other digital transmissions they hear and report information (callsign, frequency, how strong, etc.) to a server via the Internet. The server archives these "spots" and relays them via Telnet to a worldwide public network of "DX cluster" servers which anyone can connect to. During one radio contest weekend last fall, the RBN relayed over 7 million spots, or over 40 per second. In addition to their support of amateur radio operating, the RBN archives are also being used for serious studies of the ionosphere. Early last year, an article in Space Weather Quarterly used RBN observations to shed new light on what happens during a solar flare. For more information, see http://www.reversebeacon.net/m... and http://reversebeacon.blogspot.... 73, Pete N4ZR