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.]

Comments

Link to Kickstarter

[cerberusss]

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...

Re:Link to Kickstarter

[MindPrison]

Yep, can't click on a single SDR receiver link, all busy - max 4 users per SDR it seems.

If the NSA did this, you'd think it was creepy.

[Dr_Barnowl]

Now we're crowdfunding a world wide surveillance network.

Re:If the NSA did this, you'd think it was creepy.

[RobinH]

No, nobody thinks it's creepy to pick up over-the-air radio signals wherever they are in the world. This thing doesn't automatically decrypt or anything like that. It's just a receiver. The cool part is that it's receiving and storing every single frequency simultaneously, and then you use a software bandpass filter to get just the station or frequency you want. No different than having a DVR that could simultaneously record every TV channel. Installing a rootkit on everyone's phone to remotely activate the camera and/or microphone - that's creepy. Connecting IoT sensors in your house and having them upload everything to the "cloud," - that's creepy.

Re:If the NSA did this, you'd think it was creepy.

[fyngyrz]

What is so significant in 0 to 30 MHz.

Shortwave stations from every continent. Longwave stations. The long established 160-, 80-, 40-, 20-, 15-, and 10-meter ham bands, as well as the newer (and lower bandwidth) WARC bands. Time and frequency reference stations. Weather fax. Lots of pirate radio. Various textual and other FSK encoded data transmissions. Beacons. Natural phenomena such as solar RF emissions. The AM radio bands. Maritime weather broadcasts. Citizen's band radio (both European and US band spans.) All manner of military and commercial and non-military government signals.

In addition, because of the way RF propagates through the atmosphere, signals at these frequencies are far better able to reach long distances than signals at higher frequencies; get much higher than 50 MHz, and reliable reception falls down into line-of-sight distance without the assistance of intermediate receive-and-re-transmit relay stations such as towers or satellites.

During the course of the day, the propagation characteristics of the atmosphere change, primarily due to varying exposure to solar radiation. This varies with solar output and events, terrestrial weather, and can even be affected to some degree by intentional energy delivery by technological means.

There are also signals at the low end that are electromagnetically sourced that have been found to presage events such as earthquakes.

If one goes to the (very minor) effort of converting from other types of signals, for instance from sound (air pressure variation) to electrical (IOW, use a microphone or a speaker-as-microphone), you can look into information realms normally out of perceptibility. For instance, I have a couple of old super-tweeters mounted in my attic and this enables me to check out the otherwise inaudible chirps and whistles of the bats that live up there (I have a bat habitat.)

There is more in the world than data packets. That doesn't mean these things will be of interest to everyone; but they are definitely of interest to some, and so that's what gives SDR hardware designed to work in this particular frequency range real value.

I write software for SDRs; it works with any frequency range the SDR is capable of, and because I do this, I have quite a few SDRs on the bench at any one time, and quite a range of frequency capabilities. I live in a fairly rural area, and for me, there is a lot more interesting going on from 0-30 Mhz than there is within 30 MHz and above. It's all in what tweaks your particular curiosities and leanings. :)

Re:If the NSA did this, you'd think it was creepy.

[fyngyrz]

I have one here, and hope to write a proper network server for it; right now its in limbo, as they're being spotty in terms of developer communications. As it stands -- as a USB interface device -- it suffers from the wildly differing USB APIs between linux, OS X and Windows. Supporting it directly means writing three completely different sets of code; supporting it via the supplied libraries means low OS revision compatibility.

So far, the best bang for the buck I've run into are the ANDRUS MK 1.5, AFEDRI and RFSPACE models for 0-30 MHz. For above, the cheap and obvious way is an el cheapo USB stick, with which you can do some fun things, but the units have all kinds of weak points and you will definitely run into them if you use them in any kind of real RF surfing. They make really fun commercial FM receivers if the stations are reasonably local. And preamps can make them into real monsters, FM-wise. I regularly listen to a station almost 200 miles away here on the plains. In decent fidelity, in stereo.

This unit looks to have a proper ethernet interface, but the kickstarter page doesn't seem to specifically say so - I'm going by the picture. If it does, then it may be possible (should be, I would think) to support it beyond the minimal web interface they're talking about on the page. The direct sampling design is a very, very attractive feature and can potentially result in awesome RF capabilities, all depending on the unit's front end. And I love the idea of the integral GPS unit. You can do some really cool things with a solid frequency reference. Like this, for instance.

Funny

[Teun]

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.

Re: If the NSA did this, you'd think it was creepy

[anegg]

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.

Tried and failed?

[camperdave]

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.

Re:Tried and failed?

[TopSpin]

Television is broadcast in VHF and UHF; well above 30Mhz.. These SDR receivers won't pick up any broadcast television. If any AM radio stations care enough to sue over this (something they haven't bothered to do so far, despite WebSDR existing) it's easy to filter the broadcast AM bands, or anything else that has to be blocked.

In other very interesting SDR news; last month David Rowe did a linux.conf.au presentation that covered his work on fully open source (from the boards and firmware through the protocol stack) digital VHF radio. This will ultimately lead to cheap (sub $100) and powerful TDMA repeaters for VHF and UHF. Essentially this brings cellular radio technology to amateur radio bands.

WebSDR

[32771]

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.

Re:For What?

[Shoten]

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.

Re:Who cares ?!?

[slashping]

Shortwave is between 1.6 MHz and 30 MHz.