Category: RTL-SDR

WebWSPR: A Browser Based WSPR Decoder and Visualization Tool

A few days ago we posted about [dj0abr / Radio Electronics'] WebSDR software for QO-100. Having looked through his GitHub we've seen that he also has an a similar browser based server tool called WebWSPR for WSPR decoding and visualization (click with WebWSPR link) which was released earlier this year.

WSPR is an amateur radio digital HF mode designed to be decodable even if the signal is transmitted with very low power and is very weak. It can be used to help determine HF radio propagation conditions as WSPR reception reports are typically automatically uploaded to wsprnet. In the past we have been able to receive WSPR and similar modes like FT8 with our RTL-SDR V3 running in direct sampling mode.

Like his QO-100 WebSDR software, WebWSPR is designed to run on a single board computer like a Raspberry Pi or any Linux machine. It serves a web page that shows the WSPR waterfall, decoded data and has various WSPR related control options. The web page can be accessed remotely from any machine on the same network as the server, or could be put on the internet with port forwarding and a hostname service like noip.

A ready to use Raspberry Pi image for WebWSPR is available here (does not seem to support the latest Pi4 or 3B+ however). Manual installation instructions can be found here. The code is all open source and available on GitHub.

The software appears to take input from the soundcard for standard hardware receivers, but it should be possible to pipe audio from an RTL-SDR into pulseaudio, which the software can then use. The instructions from our RTL-SDR V3 WSJT-X tutorial may help.

WebWSPR Browser Screenshot
WebWSPR Browser Screenshot

Hackaday Article about the Slow Death of NOAA-15

If you've been following our blog, or have your own RTL-SDR based weather satellite station, then you'll know that the NOAA-15 APT satellite has been experiencing issues lately. There appear to be problems with it's camera scan motor resulting from it running low on lubrication. This is fully understandable as the satellite is 21 years old and well past it's expected life span. The satellite appears to be working some days, and producing garbage image other days.

Over on Hackaday, Dan Maloney has uploaded an interesting article that explores the history and technology behind NOAA-15's camera, and why it is now failing.

When NOAA-15 fails for good, don't feel too bad as we still have NOAA-18 and NOAA-19, the Russian Meteor M2, and Meteor M2-2 satellites, and the GOES satellites, all of which can be received by an RTL-SDR. Several new weather satellites are also planned for 2020 and onwards.

Talks from GNU Radio Days 2019

GNU Radio Days 2019 was a workshop held back in June. Within the last week recordings of the talks have been uploaded to YouTube by the Software Defined Radio Academy channel. The talks cover a wide range of cutting edge SDR research topics and projects. Many of the presenters have also made use of RTL-SDR dongles, as well as other higher end SDRs in their research.

All the talks are combined into two 3 hour long videos from the morning and day sessions from day one. Day two also has two videos that consist of recordings from the tutorial sessions which make use of the PlutoSDR. Finally there is also the keynote speech from Marcus Müller where he dives into the internal workings of GNU Radio.

Below we list the talks with timestamps for the YouTube video. Short text abstracts for each of the talks can also be found in the conference book. We note that not all the abstracts appear to have been presented in the videos, so it may be worth checking out the book for missed talks about passive radar, a 60 GHz link, embedded GNU Radio on a PlutoSDR, an SDR 802.11 infrared transmission system, PHY-MAC layer prototyping in dense IoT networks and hacking the DSMx Drone RC protocol.

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Android ADS-B Flight Tracker with 3D Aircraft Display

ADSB Flight Tracker is an Android App that allows you to display ADS-B flight data in either 2D or 3D. It works either with data shared from others over the internet via aggregation sites like adsbexchange.com, or via your own home ADS-B receiver data coming from an RTL-SDR and dump1090 server on your home network. You can also directly connect to an RTL-SDR that is running on your phone and this will allow you to get data faster with less lag. Using data shared by others from the internet could have a delay of a few seconds.

In order to keep using the 3D and RTL-SDR features you'll need to unlock them for a small in-app purchase of $2 for each feature. Initially you get about 30 minutes trial time however.

2D and 3D Screenshots from ADS-B Flight Tracker
2D and 3D Screenshots from ADS-B Flight Tracker

Some interesting 3D videos were also recently posted to the apps Twitter page @ADSBFlightTrkr

SDRTrunk 0.4.0 Alpha 9 Updates Highlighted

You may recall that a few years ago we released a tutorial on how to set up and use [SDRTrunk]. Fast forward a few years and the software has seen numerous changes. This application was designed primarily for tracking trunking radio systems but also has the ability to decode things like MDC-1200, LoJack and more.

The software is compatible with many Software Defined Radios such as our RTL-SDR v3, HackRF and the Airspy. Some of the newer improvements include a bundled copy of java so that an installation of java is not required on the host computer, as well as decoding improvements for P25 among other digital voice modes. You can find a full list of improvements along with the latest release on [GitHub]

The biggest feature many have been waiting for is the ability to import talk groups for their radio system into the application from radio reference. While this has not yet been implemented, user [Twilliamson3] has created a [web application] that will convert table data from radio reference into a format that is supported by SDRTrunk.

SDRTrunk Screenshot
SDRTrunk Screenshot

GNU Radio 3.8.0.0 Released – First Minor Release Version in Six Years

GNU Radio is an open source digital signal processing (DSP) toolkit which is often used to implement decoders, demodulators and various other SDR algorithms. Several SDR programs are based on GNU Radio code, and it is responsible for a lot of DSP development and knowledge within the SDR and radio community. It is compatible with almost all SDR devices, including the RTL-SDR.

Recently GNU Radio has been updated to version 3.8.0.0. The release is classed as the first "minor" release version in six years, as they are going from version 3.7 to 3.8. That doesn't mean there have been no changes for six years, it just means that over the last six years all releases have remained within the 3.7 version and they have mostly been bug fixes rather than larger changes like added features. Behind the scenes over the last six years developers have been working on these larger changes, and now is the time that they have been officially released.

Marcus Müller from GNU Radio writes:

Witness me!

Tonight, we release GNU Radio 3.8.0.0.

It’s the first minor release version since more than six years, not without pride this community stands to face the brightest future SDR on general purpose hardware ever had.

Since we’ve not been documenting changes in the shape of a Changelog for the whole of the development that happened since GNU Radio 3.7.0, I’m afraid that these release notes will be more of a GLTL;DR (git log too long; didn’t read) than a detailed account of what has changed.

What has not changed is the fact that GNU Radio is centered around a very simple truth:

Let the developers hack on DSP. Software interfaces are for humans, not the other way around.

And so, compared to the later 3.7 releases, nothing has fundamentally modified the way one develops signal processing systems with GNU Radio: You write blocks, and you combine blocks to be part of a larger signal processing flow graph.

With that as a success story, we of course have faced quite a bit of change in the systems we use to develop and in the people that develop GNU Radio. This has lead to several changes that weren’t compatible with 3.7.

The changelog is too long to quote here, but as a summary they have fixed bugs, updated dependencies to newer versions, enabled C++ code generation, changed XML to YAML, moved from QT4 to QT5 and removed a few stale projects. Some of these changes could break compatibility with older GNU Radio tutorials and programs. It also seems that unfortunately due to a lack of updates, support for the Funcube Dongle has been removed.

SignalsEverywhere 10,000 Subscriber Interactive Live Stream with Giveaways on August 10 12PM EST

The SignalsEverywhere YouTube channel is quickly growing in size, and has recently passed the 10,000 subscriber milestone. If you weren't aware, Corrosive (aka KR0SIV aka Harold) who runs the channel has been consistently putting out high quality videos related to the software defined radio hobby. He's also started a podcast which also covers some interesting topics.

Some Recent SignalsEverywhere YouTube Videos
Some Recent SignalsEverywhere YouTube Videos

To celebrate hitting the 10,000 subscriber mark, Harold is planning an interactive 6 hour+ YouTube live stream which will begin on Saturday August 10 12PM EST time (11 hours from the time of this post)If you want to be automatically reminded of the stream, go to the live stream place holder, and click on set reminder.

The stream will be interactive as he is planning on setting up several SpyServer's that will be running across the HF, VHF, UHF and L-Bands. This will allow the audience to use SDR# to connect to his SDRs that are being used on the stream, allowing people to follow along with what Harold is doing on the stream, and ask questions about what they are seeing.

We're also helping to sponsor his stream and will be donating 5x RTL-SDR dongle + antenna kits, 5x RTL-SDR dongles, 1x Radarbox bundle, as well as one KerberosSDR to any giveaways that he plans on doing throughout the stream.

We really like Harolds work on YouTube, and if you are a fan of the content on our RTL-SDR.COM blog, then you really should be subscribed to his channel too.

Interactive SDR Live Stream | 10K Subscriber Celebration and Giveaway!

mySdrPlayback: MacOS Software for Browsing Through IQ Recordings from SDR#, SDRUno and More

mySdrPlayback is a program for MacOS that allows you to easily browse through IQ recordings created from multiple SDR programs. Recently the software's author (@ChrisSmolinski) 
Tweeted that he's added support for SDR# and SDRUno IQ recordings
. The program is described below:

Why use this app? It makes it easy to slog through lots of recording files, looking for interesting signals. Load a file, and a waterfall for the entire file is created. You can scroll around, and if you see anything that looks interesting, you can drag select it, and then demodulate it. You can even save the demodulated audio as a WAVE file, that you can listen to later, send to someone else, or play into your digital decoding software, if it is an RTTY, SSTV, etc. transmission.

Support for other SDR recording file formats is possible, you'll need to work with me by providing sample files and details on the format. This program is presently for macOS only. Support for Windows may happen... stay tuned!

mySdrPlayback now supports SDR# and SDRUno IQ Files.
mySdrPlayback now supports SDR# and SDRUno IQ Files.