Tagged: gnu radio

Signals and Bits A New SDR Podcast by the President of the GNU Radio Project

[Ben Hilburn] the president of the [GNU Radio Project] has recently started a new podcast called [Signals and Bits]. If you were unaware, GNU Radio is the defacto open source framework for implementing digital signal processing code. Without it, many SDR programs that we take for granted may have never been developed as it is responsible for a lot of community DSP knowledge and algorithm development.

This podcast is scheduled for a new release every Wednesday and will be composed in an interview style focusing on a multitude of topics from Software Defined Radio to Spectrum Enforcement, Radio Astronomy and so much more.

In the first episode Ben interviews Harold Giddings AKA Corrosive of [Signals Everywhere] where they discuss the state of Software-Defined radio and how he got started with radio communications having come from an IT/Computer Networking background.

Ben has already pre-recorded several episodes which will ensure great content is always just around the corner. Ben would love it if you could also send feedback his way over on the [Signals and Bits Twitter] page.

Ben Hilburn President of GNU Radio (Left), Harold Giddings AKA Corrosive of Signals Everywhere (Right)

Tracking Tagged Orangutans in the Bornean Jungle with Drones, GNU Radio and an Airspy Mini

Due to various human activities causing the environmental destruction of it's habitat, the Orangutan is now classed as a critically endangered species. In addition to being endangered, Orangutans face another problem in that they are often captured and sold as pets due to their intelligence and cuteness.

To combat these problems, NGOs, charities and rescue centers have been using RF tags on rehabilitated Orangutans that have released back into the wild. The RF tag regularly transmits a data-less pulse at VHF frequencies which is then typically tracked using direction finding equipment such as a directional Yagi antenna. The range is only approximately 200-400m. 

In order to try and alleviate the range issue Dirk Gorissen has been working on creating a drone based system that could detect the VHF transmission and create a heatmap of Orangutan positions. The first iteration of his system uses an RTL-SDR, Odroid and lightweight loop antenna. A simple Python script then monitors the spectrum and logs the drones current location, altitude, speed and heading when a pulse is detected. Tests confirmed that the signal was able to be detected from the sky, but unfortunately the drone was eventually crashed and lost before it could be properly used.

In his second try a few years later, Dirk used a larger drone and switched SDRs to an Airspy Mini with preamp. The pulse detection code was also improved by using GNU Radio to create a DSP algorithm combining peak detection, cross correlation with a known template of the signal, and a phase locked loop. Visualization and data transfer is achieved through react.js and a Flask web server running on the drones WiFi hotspot. This time with the new drone and system Dirk was able to successfully detect and locate several Orangutan's on various flights, despite noting that some RF tags appeared to be glitchy.

Orangutan Detected with Drone, Airspy Mini and GNU Radio.
Orangutan Detected with Drone, Airspy Mini and GNU Radio.
Drone used in the experiment
Drone used in the experiment

Podcast: The magic of Software Defined Radio with Ben Hilburn

Hanselminutes is a weekly podcast that aims to promote fresh technology and fresh voices to software developers. Last Friday they interviewed Ben Hilburn who is the project lead and president of the GNU Radio Foundation and Director of Engineering at DeepSig Inc who are working on combining deep learning with the signal processing. In the podcast Ben talks briefly about a broad range of topics like spectrum scarcity issues, different SDR hardware, basic SDR fundamental concepts, multipath, GPS, RF security, analogue vs digital and more. It is aimed at technical people who know little about SDR and radio.

EPISODE SUMMARY

Ben Hilburn is the Director of Engineering at DeepSig Inc., which is commercializing the fundamental research behind deep learning applied to wireless communications and signal processing. He also runs GNU Radio, the most widely used open-source signal processing toolkit in the world, serving as Project Lead and President of The GNU Radio Foundation. Ben talks to Scott about why Software Defined Radio is magical and they talk about how SDR can be used to teach STEM and solve interesting engineering problems.

EPISODE NOTES

Ben Hilburn is the Director of Engineering at DeepSig Inc., which is commercializing the fundamental research behind deep learning applied to wireless communications and signal processing. He also runs GNU Radio, the most widely used open-source signal processing toolkit in the world, serving as Project Lead and President of The GNU Radio Foundation. Ben talks to Scott about why Software Defined Radio is magical and they talk about how SDR can be used to teach STEM and solve interesting engineering problems.

More Talks from GNURadio Con 2018

Last week we posted about some videos of talks from the 2018 GNU Radio Conference which had been release on YouTube. This week a few more videos have been released and we display a small selection below. The full collection of videos can be found on their YouTube channel.

RF Ranging with LoRa Leveraging RTL-SDRs and GNU Radio

Wil Myrick discusses the use of RTL-SDRs and GNU Radio to create a low cost LoRa RF ranging prototype, to aid in the localization of IoT transmitters.

GRCon18 - RF Ranging with LoRa Leveraging RTL SDRs and GNU Radio

Using GNU Radio and Red Pitaya for Citizen Science

Robert W McGwier discusses the use of Red Pitaya SDRs and GNU Radio for use in citizen science ionosphere measurement experiments.

GRCon18 - Using GNU Radio and Red Pitaya for Citizen Science

SETI Breakthrough Listen

Steve Croft discusses the Search for Extraterrestrial Intelligence (SETI) project and how software defined radio is being used in the search.

GRCon18 - SETI Breakthrough Listen

Talks from the 2018 GNU Radio Conference

GNU Radio is a very powerful open source platform for implementing various digital signal processing (DSP) algorithms. It is very commonly used with software defined radios like the RTL-SDR, as well as much higher end units. The community that uses GNU Radio is very large, and so every year they hold a conference that highlights some of the most interesting applications and developments related to GNU Radio. The 2018 GNU Radio conference was held in Las Vegas during September 2018. Recently they have uploaded the talks to YouTube, and below we're posting some of our favorites. The full list can be found on their YouTube channel.

Keynote Talk: SatNOGs

In this keynote talk Manolis Surligas discusses the SatNOGs project. SatNOGs is a non-profit organization creating an open source and volunteer based satellite ground station network.

GRCon18 - Keynote: SatNOGs

Open Source Radio Telescopes

John L. Makous discusses his work in creating low cost and home made horn antenna radio telescopes designed to receive the 21cm hydrogen line and other astronomical objects and phenomena. The idea is to provide a low cost solution and easy to build telescope to use in schools.

GRCon18 - Open Source Radio Telescopes

Enter the Electromagic Spectrum with the USRP

Nate Temple gives us an overview of several signals that have been decoded with GNU Radio flowgraphs.

GRCon18 - Enter the Electromagic Spectrum with the USRP

Software Defined Radar Remote Sensing and Space Physics

Juha Vierinen discusses using a USRP to measure propagation conditions with ionospheric chip sounders, and improvements to chirp sounders by using spread spectrum noise. He also discusses various other radar techniques and applications.

GRCon18 - Software Defined Radar Remote Sensing and Space Physics

Video Tutorial: Installing GNU-Radio on Windows 10

Over on YouTube user Petr Horký has uploaded a helpful tutorial video showing how to install GNU Radio on Windows 10. Petr goes through the steps from installing Python, pip and other dependencies like numpy and pyqt, to installing GNU Radio itself and then ensuring that the system PATH is set correctly.

GNU Radio is a block based programming language for building digital signal processing applications (e.g. demodulators/decoders). It is very useful for experimenting with more advanced SDR concepts, and there are also many RTL-SDR compatible applications built with GNU Radio as well. GNU Radio is typically run on Linux, but can also run on Windows now too, although perhaps not every program will be compatible.

How to install GNU Radio Companion on Windows 10 (pip, environment variables)

Receiving GOES Weather Satellite Images with GNURadio and XRITDecoder in Windows

Thank you to ON7NDR as well as CM2ESP for submitting and figuring out a way to get GOES 16 decoding working with RTL-SDR using the free XRITDecoder, Xrit2Pic software and GNU Radio for Windows. 

ON7NDR's story is that he wanted to be able to receive GOES 16, but not being familiar with Linux he wanted a Windows based solution. He writes that the credit to finding the solution goes to CM2ESP who has written up a tutorial (pdf) explaining how to set everything up in Windows. ON7NDR has also written a separate complimentary tutorial (docx) that explains some steps in CM2ESPs tutorial a little further and provides a few tips on choosing correct the correct version of GNU Radio. He's also provided a screenshot showing what the correct config file looks like for an RTL-SDR dongle.

We note that for Windows there is also USA-Satcom's XRITDecoder, however this is closed source software which costs $100 USD.

GOES Full Disk Image of the Earth
GOES Full Disk Image of the Earth

Demonstrating Two Channel Coherent Spatial Filtering In a GNU Radio Simulation

Over on YouTube VE6EY has uploaded a video that demonstrates spatial filtering (aka beamforming) working in a GNU Radio simulation. This is a technique that can be used with a 2-channel coherent SDR with to nullify local interference. One SDR is connected to an antenna for receiving the distant signal, and the second is connected to a noise probe that is designed to receive only the local noise source.

The demonstration is not performed with real SDRs, but with prerecorded signals, although it still shows the effectiveness of the technique. In the video VE6EY shows switch mode and powerline noise being nulled out from some AM music, and explains through a demo why phase coherence is required.

V36EY gives further information and a link to download the demo over on his blog post.

SDR Spatial Filtering Demo