Category: News

Live Right Now: The 12th Cyberspectrum Software Defined Radio Meetup

Cyberspectrum is a monthly software defined radio meetup that is held in San Francisco. During this meetup presenters show and discuss their SDR related work. The 12th Cyberspectrum meetup is occurring right now and this time there will be presentations from amateur radio astronomer Marcus Leech from Canada and wireless security researcher Tobias Zillner from Austria.

There is a live stream on YouTube shown below, and after it finishes it will also be available for viewing:

Edit: Stream is over. Marcus Leech gave a nice talk that gave an overview or amateur radio astronomy and explained some of his set up where he uses RTL-SDR dongles as the receiver.

The overview of today’s presentations are as follows:

Marcus Leech from SBRAC“An integrated proof-of-concept ‘all-digital’ feed for 21cm radio astronomy”

We show ongoing work in designing and building a proof-of-concept ‘all digital’ feed for 21cm radio astronomy experiments. While many professional radio astronomy observatories are using “digitize at the feed” techniques, amateur experiments (and successes) in this are very close to non-existent.

Digitizing at the feed carries many advantages, including overall system gain stability, and the ability to carry signals over cheap ethernet-over-fiber links.

We’ll show an example feed arrangement that uses a differential radiometry approach, and does much of the initial processing right at the feed, including radiometry and spectral calculations, sending summary data to an ordinary PC host over ethernet.

Challenges and pitfalls will be discussed.

Tobias Zillner from Cognosec: “ZigBee Smart Homes – A Hacker’s Open House”

ZigBee is one of the most widespread communication standards used in the Internet of Things and especially in the area of smart homes. If you have for example a smart light bulb at home, the chance is very high that you are actually using ZigBee by yourself. Popular lighting applications such as Philips Hue or Osram Lightify and also popular smart home systems such as SmartThings or Googles OnHub are based on ZigBee. New IoT devices have often very limited processing and energy resources. Therefore they are not capable of implementing well-known communication standards like Wifi. ZigBee is an open, public available alternative that enables wireless communication for such limited devices.

ZigBee provides also security services for key establishment, key transport, frame protection and device management that are based on established cryptographic algorithms. So a ZigBee home automation network with applied security is secure and the smart home communication is protected?

No, definitely not. Due to “requirements” on interoperability and compatibility as well as the application of ancient security concepts it is possible to compromise ZigBee networks and take over control of all included devices. For example it is easily possible for an external to get control over every smart light bulb that supports the ZigBee Light Link profile. Also the initial key transport is done in an unsecured way. It is even required by the standard to support this weak key transport. On top of that another vulnerability allows third parties to request secret key material without any authentication and therefore takeover the whole network as well as all connected ZigBee devices. Together with shortfalls and limitations in the security caused by the manufacturers itself the risk to this last tier communication standard can be considered as highly critical.

This talk will provide an overview about the actual applied security measures in ZigBee, highlight the included weaknesses and show also practical exploitations of actual product vulnerabilities. Therefore new features in the ZigBee security testing tool SecBee will be demonstrated and made public available. 

SDR Presentations Requested for FOSDEM

The Free and Open Source Developers Meeting (FOSDEM) is looking for SDR presentations to give at this years conference in Brussels, Belgium which will be held on January the 80th & 31st of January.

Software Radio has become an important tool to allow anyone access the EM spectrum. Using free software radio libraries and applications and cheap hardware, anyone can now start hacking on wireless communications, remote sensing, radar or other applications. At FOSDEM, we hope to network all these projects and improve collaboration, bring new ideas forward and get more people involved.

The track’s web site resides at:

Here, we will publish updates and announcements. The final schedule will be available through Pentabarf and the official FOSDEM website.

To suggest a talk, go to and follow the instructions (you need an account, but can use your account from last year if you have one). You need to create an ‘Event'; make sure it’s in the Software Defined Radio track! Lengths aren’t fixed, but give a realistic estimate and please don’t exceed 30 minutes unless you have something special planned (in that case, contact one of us). Also, don’t forget to include time for Q&A. Typical slot lengths would be 30 Minutes including QA.

You aren’t limited to slide presentations, of course. Be creative. However, FOSDEM is an open source conference, therefore we ask you to stay clear of marketing presentations. Of course, we like nitty-gritty technical stuff.

We will reserve time for interactiveness, it won’t all be talks.

If you are qualified and interested in giving a talk the submission deadline is December 4th 2015.


An RTL-SDR Based Smartwatch for Detecting Objects Touched by the Wearer

Disney Research have just released a paper describing an RTL-SDR based smart watch that they’ve developed a proof of concept for. The smart watch is unique in that it can be used to actually detect the exact object that the wearer is touching. 

The prototype watch does this by using the RTL-SDR to detect the electromagnetic (EM) noise emitted by particular objects and compare it against a stored database. They call this technology EM-Sense. In the paper the authors summarize:

Most everyday electrical and electromechanical objects emit small amounts of electromagnetic (EM) noise during regular operation. When a user makes physical contact with such an object, this EM signal propagates through the user, owing to the conductivity of the human body. By modifying a small, low-cost, software-defined radio, we can detect and classify these signals in real-time, enabling robust on-touch object detection. Unlike prior work, our approach requires no instrumentation of objects or the environment; our sensor is self-contained and can be worn unobtrusively on the body. We call our technique EM-Sense and built a proof-of concept smartwatch implementation. Our studies show that discrimination between dozens of objects is feasible, independent of wearer, time and local environment.

The frequencies required for EM detection are around 0 – 1 MHz which falls outside the range of the RTL-SDR’s lowest frequency of 24 MHz. To get around this, they ran the RTL-SDR in direct sampling mode. The RTL-SDR is connected to the watch, but a Nexus 5 smartphone is used to handle the USB processing which streams the signal data over WiFi to a laptop that handles the signal processing and live classification. In the future they hope to use a more advanced SDR solution, but the RTL-SDR has given them the proof of concept needed at a very low cost.

An example use scenario of the watch that Disney suggests is as follows:

Home – At home, Julia wakes up and gets ready for another productive day at work. Her EM-Sense-capable smartwatch informs and augments her activities throughout the day. For instance, when Julia grabs her electric toothbrush, EMSense automatically starts a timer. When she steps on a scale, a scrollable history of her weight is displayed on her smartwatch automatically. Down in the kitchen, EM-Sense detects patterns of appliance touches, such as the refrigerator and the stove. From this and the time of day, EM-Sense infers that Julia is cooking breakfast and fetches the morning news, which can be played from her smartwatch. 

Fixed Structures – When Julia arrives at the office, EMSense detects when she grasps the handle of her office door. She is then notified about imminent calendar events and waiting messages: “You have 12 messages and a meeting in 8 minutes”. Julia then leaves a reminder – tagged to the door handle – to be played at the end of the day: “Don’t forget to pick up milk on the way home.” 

Workshop – In the workshop, EM-Sense assists Julia in her fabrication project. First, Julia checks the remaining time of a 3D print by touching anywhere on the print bed – “five minutes left” – perfect timing to finish a complementary wood base. Next, Julia uses a Dremel to cut a piece of wood. EM Sense detects the tool and displays its rotatory speed on the smartwatch screen. If it knows the task, it can even recommend the ideal speed. Similarly, as Julia uses other tools in the workshop, a tutorial displayed on the smartwatch automatically advances. Finally, the 3D print is done and the finished pieces are fitted together.

Office – Back at her desk, Julia continues work on her laptop. By simply touching the trackpad, EM-Sense automatically authenticates Julia without needing a password. Later in the day, Julia meets with a colleague to work on a collaborative task. They use a large multitouch screen to brainstorm ideas. Their EM-Sense-capable smartwatches make it possible to know when each user makes contact with the screen. This information is then transmitted to the large touchscreen, allowing it to differentiate their touch inputs. With this, both Julia and her colleague can use distinct tools (e.g., pens with different colors); their smartwatches provide personal color selection, tools, and settings. 

Transportation – At the end of the day, Julia closes her office door and the reminder she left earlier is played back: “Don’t forget to pick up milk on the way home.” In the parking lot, Julia starts her motorcycle. EM-Sense detects her mode of transportation automatically (e.g., bus, car, bicycle) and provides her with a route overview: “You are 10 minutes from home, with light traffic”.

The EM-Sense watch detecting a door. The RTL-SDR dongle is the small square box under the watch.
The EM-Sense watch detecting a door. The RTL-SDR dongle is the small square box under the watch.

Meteor M-N1 Satellite Wakes up from the Dead reader Happysat recently wrote in with some news. A few days ago a weather satellite image decoding enthusiast from Argentina was waiting for a pass of the Russian Meteor M-N2 satellite when he discovered a strong LRPT signal at 137.1 MHz, even though the Meteor M-N2 satellite was not in sight yet. It turns out that the signal was coming from the old Meteor M-N1 satellite which was supposed to have been shut down in September 2014 due to several problems it had. The received signal is strong enough to produce a good black and white weather image, but because the satellite is not longer physically stable, sometimes the Earth’s curve can be seen in the images.

Recent images received from the resurrected Meteor M-N1 weather satellite.
Recent images received from the resurrected Meteor M-N1 weather satellite.
Recent images received from the resurrected Meteor M-N1 weather satellite.
Recent images received from the resurrected Meteor M-N1 weather satellite. The stabilization system has failed so the earth’s curve can be seen.

The exact reason as to why it is transmitting again is unknown, but it is speculated that it is due to a breakdown of the chemicals in the batteries. Last year we posted about how sometimes satellites which have been decommissioned and shut down can spontaneously begin transmitting again when their batteries undergo a chemical change due to thousands of failed recharge cycles. The chemical change allows the batteries to conduct electricity from the solar panels directly to the electronics, which on Meteor M-N1 could be reactivating the transmitters and imaging sensors. If this is what happened then the satellite will only be able to transmit during the day.

The Meteor M-N2 satellite is the currently official active satellite. It transmits weather satellite images with the LRPT protocol which can be received and decoded with an RTL-SDR dongle. We have a previous post on this showing an offline LRPT decoding tutorial and more recently a tutorial showing how to decode LRPT in real time. The same processes can now be adapted to the resurrected Meteor M-N1 satellite by choosing the 80K symbol rate option in the LRPT decoder.

Happysat who submitted this news originally writes:

A few days ago some guy in Argentina was waiting for the pass of Meteor M-N2 and on SDRSharp waterfall he did see LRPT Digital signals on 137.100MHz, but Meteor M-N2 was not in sight yet…

This relatively strong signal was coming from the defunct Meteor M-N1 satellite left out of control in September 2014 last year and was shutdown, although LRPT Transmissions in the past where very limited and sporadic.

Meteor M-N1 did suffer from many problems at this was the first Russian digital weather satellite in the M-series onboard many hardware in experimental stages.

After this report I tried also to capture some signals from Meteor M-N1 (some other amateurs already got small portions of images) but the satellite only transmits in direct sunlight, batteries are not charging any more.

Indicating maybe like the other older ‘deadsat’ some chemical reaction did occur inside the batteries so the power goes from the solar panels directly to the transmission parts.
It did happen before, mostly on older satellite’s only a unmodulated carrier is present when the sunlight conditions are optimal.

Surprisingly after I did record and process the 80K symbol rate QPSK signal from Meteor M-N1 with Vasili’s excellent QPSK Plugin a very nice image was generated!

Not only the sunlight provides power to the transmission part but also there is enough power to activate the imaging system which is quite amazing!

Visible channels 1-2-3 are fully working but the image is only Black and White Calibaration of the sensor are not okay so no color images can be created.

Nevertheless its a very nice addition for current LRPT weather amateurs and a big surprise its even working better when nobody controls it ;)

Because the stabilisation system failed there is no proper correction to orientate the camera and on some passes one can see the earths curve!

There are some conflicting reports about the status of Meteor M-N1 found on the internet:

Status Inactive
Details on Status (as available)

  • MSU-MR was functional with limitations (calibration issues and higher noise level in the IR channels).
  • MTVZA-GY instrument was functional with limitations due to failures of on-board memory and atmospheric sounding channels.
  • Severjanin instrument non-operational.
  • DCS was functional with limitations due to interferences to signals from ground sources.
  • GGAK-M was operational with significant limitations.
  • LRPT was functional with limitations due to information compression errors.
  • Finally, the stabilisation system failed on 23 September 2014 and the instruments could longer be operated.

On October 1, 2014 Meteor-M No 1 was withdrawn from operational use and transferred to the study of the chief designer. The decision on further operation of the spacecraft will be taken upon completion of the research program.

Its not clear the problems did got solved, and I ‘think’ M-N1 started a second life on his own. Time will tell how long the satelitte will function.

Some details:

The Meteor M-N1 Satellite.
The Meteor M-N1 Satellite.
A color image received on Meteor M-N1. Colors may not be perfect.  Submitted by Jan.
A color image received on Meteor M-N1. Colors may not be perfect. Submitted by Jan.

SDR# updated to revision 1400 & SDR Touch updated to V2.6

The popular SDR# software which is often used together with RTL-SDR dongles has recently been updated to revision 1400. This new revision brings an interesting new feature which automatically estimates and displays the peak, floor and signal to noise ratio (SNR) values of the currently tuned bandwidth. Watching the SNR metric is very useful when tuning the RF gain settings, as best reception is obtained when the SNR value is maximised. The author also writes that there have been several radical changes to the code that leverage the latest .Net 4.6 framework which should improve the signal processing quality, CPU usage, user experience and hardware support. The changelog is pasted below:

Enhanced the Center tuning mode and extended it for RTL-SDR;
Enhanced the spectrum display;
Changed the frequency labelling to use multiples of 2.5/5/10 or frequency steps;
Added Peak, Floor and SNR estimation for the selection;
Enhanced the defaults for better user experience;

We note that some plugins may break with this update so be sure to make a backup if upgrading. Vasili, one of the most active SDR# plugin programmers has updated most of his plugins to work on this new version now.

Revision 1400 of SDR# with SNR estimation.
Revision 1400 of SDR# with SNR estimation.

In addition to this update, over on the Android OS the popular mobile app SDRTouch has been updated to version 2.6. This new version brings the following features and improvements:

  • Baseband recording and file playback
  • Direct sampling support for full-band receivers
  • Improved SSB image rejection
  • Fixed tuning step
  • Manual filter bandwidth
  • Improved accessibility
  • Bug fixes

Airspy Revision 2 Released

The Airspy is a $200 USD software defined radio that has a frequency range between 24 – 1700 MHz, bandwidth of up to 10 MHz and a 12-bit ADC. We consider it to be a good upgrade from those who have gotten into SDR via the low cost RTL-SDR.

Recently the Airspy hardware was updated to revision two. The new revision improves upon the first design by reducing noise, improving the USB connector, improving the ESD protection and improving compatibility with the soon to be released Spyverter upconverter. The full release is pasted below:

We have sensitive ears! The demand for ever cheaper, higher performance and ruggedized SDR receivers is driving the professional market. Due to the large demand from our professional customers, we upgraded recently our original Airspy One design to Revision 2. This new revision improves the following points:

  • Better USB noise immunity
  • Better ESD protection on the RF input
  • Added ESD protection on the dual High Speed ADC inputs
  • Better RF Shielding
  • Better RF Filtering
  • Replaced the USB connector with a custom designed, more robust, 4 through hole points model
  • Better thermal stability
  • Better compatibility with the SpyVerter

The old revision is no longer produced, and all new shipments will be based on the R2. We are eager to get your feedback about these improvements!

The Airspy software defined radio


Changes to SDR#: Update to .NET 4.6, Linux support and new install procedure

SDR# (SDRSharp) is probably the most popular software program that is used with the RTL-SDR. It is free, fast and fairly easy to use.

SDR# is coded in C# and so runs on the Microsoft .NET runtime. SDR# has always used the 3.5 version of the .NET runtime, however recently the programmers have made the decision to upgrade the runtime used to the latest 4.6 version of .NET. For non-programmers this means that compatibility with newer operating system such as Windows 10 is enhanced, performance and stability is improved and that SDR# can now be run on Linux and OSX with Mono 4.0. The downside is that Windows XP and Vista are no longer supported operating systems (Vista SP2 is supported). An OS compatibility list for .NET 4.6 can be found here.

If you are an SDR# user and run an older operating system such as XP or Vista we suggest that you either upgrade your OS, or simply continue to run the older versions of SDR#.

In addition to the new changes, the install procedure has also changed. Firstly, the old website now redirects to To install SDR# now, simply download SDR# zip file from Unzip it to any folder on your PC. Next, to download the RTL-SDR drivers simply run the install-rtlsdr.bat file. We will soon be updating our Quickstart guide to incorporate these changes.

To install SDR# on Linux or OSX you can follow the guide over at

The official announcement is as follows:


We have been relying on the .NET Framework 3.5 for quite some time until it’s no longer installed by default into the new operating systems. Microsoft also provides minimalist support of this version of the Framework on Windows 10 which handicaped the core and plugin developers in many ways. This also resulted in obscure bugs in the user base. So we moved recently the entire code base to the .NET 4.6 in order to refresh the software and make it compatible with modern operating systems like Windows 10.

This has many implications:

  • Better performance
  • Better programming API
  • Support of Windows 10
  • Support of Linux and Mac with Mono 4.0 and up
  • End of support of Windows XP and Vista
  • End of support of the ExtIO interface (not portable)

We coordinated this migration with all the plugins and front-ends developers so no body misses the boat.
The installation procedure has also changed and now the main package contains a batch file to download the dependencies required to run RTL-SDR.
This might be disturbing for a few, but the overall impact was judged positive and a better investment for the future, especially with the new API offered by .NET 4.6.


The SDR# Team


DesktopSDR MATLAB RTL-SDR Text Book Released

Back in August we posted about an RTL-SDR related text book called DesktopSDR that was due to be released later in the month. The text book discusses technical SDR topics, with the RTL-SDR used as the radio receiver and MATLAB used as the digital signal processing tool. It looks to be very useful to students of radio or communications engineering. There were a few delays with the release, but it is now out at The eBook version is free whilst the print version is soon to be released on Amazon for about $68 USD for the paperback and $89 USD for the hard back

To go along with the book they have also released several accompanying videos that are available at

The books blurb reads:

The availability of the RTL-SDR device for less than $20 brings software defined radio (SDR) to the home and work desktops of EE students, professional engineers and the maker community. The RTL-SDR can be used to acquire and sample RF (radio frequency) signals transmitted in the frequency range 25MHz to 1.75GHz, and the MATLAB and Simulink environment can be used to develop receivers using first principles DSP (digital signal processing) algorithms. Signals that the RTL-SDR hardware can receive include: FM radio, UHF band signals, ISM signals, GSM, 3G and LTE mobile radio, GPS and satellite signals, and any that the reader can (legally) transmit of course! In this book we introduce readers to SDR methods by viewing and analysing downconverted RF signals in the time and frequency domains, and then provide extensive DSP enabled SDR design exercises which the reader can learn from. The hands-on SDR design examples begin with simple AM and FM receivers, and move on to the more challenging aspects of PHY layer DSP, where receive filter chains, real-time channelisers, and advanced concepts such as carrier synchronisers, digital PLL designs and QPSK timing and phase synchronisers are implemented. In the book we will also show how the RTL-SDR can be used with SDR transmitters to develop complete communication systems, capable of transmitting payloads such as simple text strings, images and audio across the lab desktop.

Download the book at
Download the book at