Skywave Linux:
Global Software Defined Radio at Your Fingertips

What is Skywave Linux?
Supported SDR Types
Decoders and Digimodes
Usage and Installation
Apps for Coders
Command Line Tools
Technical Notes

Acknowledgements
System Integrity and Authenticity
Disclaimer
Special Notes and Bug Fixes
Apps in this Version of Skywave Linux
Skywave Linux Demo Video

Skywave Linux... What's That?

Turn your PC into the ultimate shortwave receiver. And more.

Skywave Linux is an operating system using bleeding-edge technology to robustly access broadcast media, utility, military, and amateur radio signals from almost anywhere in the world, using distant servers on the internet and locally connected hardware. Skywave Linux is set up to connect easily to any of the networked, state of the art software defined radio (SDR) servers. There are several hundred of them, making it possible to enjoy high performance SDR operation without any requirement of you to set up large antennas or own radio hardware. All you need to do is boot the system on a computer with internet connectivity, find a remote SDR server in your region of interest, and tune across the spectrum to find signals. Skywave Linux contains drivers to operate numerous types of SDR hardware, plugged into the your computer or on the local network. Downloading, installing and configuring SDR software can be difficult for many computer users; Skywave Linux eliminates the hassle by including several applications installed, configured, and ready to run.

The wallpaper shows a close up view of the Edwin Armstrong Tower, where the first FM radio transmissions were made.

Supported SDR Types

Several types of software defined radios are supported by Skywave Linux:

• WebSDR servers are located all over the world and provide easy access to the global airwaves through the web browser. In Skywave Linux, the web browser is packed with a curated set of bookmarks linking to the best servers. Thus, a moderately broad internet connection is all one needs to enjoy clean, stable, AM / FM / SSB reception using this cutting edge technology. WebSDR servers at the University of Twente (NL) and Washington, D.C. (USA) are particularly good, for example.
• KiwiSDR servers are a popular type of internet accessible radio, with hundreds operating at any time. Use the curated set of web browser bookmarks to access several excellent sites around the world, such as the server in Victoria, British Columbia (Canada).
• RTL-SDR devices used on the local computer system. Just plug-and-play! SDRPlusPlus and CubicSDR are the main applications for receiving AM / FM / SSB modes on local hardware. Dump1090 is for monitoring aircraft ADS-B transmissions. ADS-B mapping is available with the help of Python3 libraries. ADS-B data is also logged to an SQLite database for further analysis if desired. ACARSDec and VDLM2dec are multichannel decoders for aeronautical VHF data modes. Each is capable of simultaneously monitoring several channels at once without scanning and also logging the data to an SQLite database file. RTLSDR-Airband is a hardware agnostic, multichannel monitor for AM or FM voice modes (not limited to airband), capable of simultaneously monitoring several channels without scanning, mixing and streaming audio locally (via PulseAudio) or to the internet (via Icecast server).
• Ettus Research USRP devices, offering advanced features and high performance. Their hardware can cover frequencies from DC through 6 GHz in a diverse array of signal modes.
• Airspy, BladeRF, and ADALM-PlutoSDR offer higher performance than RTL-SDR dongles. These devices feature stable and clean oscillators, sensitive front end circuitry, superior RF filters, broader RF bandwidths, and higher resolution ADC chipsets. CubicSDR and Gqrx are the applications built for running these devices.

The key to getting most SDR devices and software to function on Linux is having proper drivers installed. Skywave Linux broadly supports these with a combination of compiled driver software and Debian repository packages, including the SoapySDR ecosystem.

Decoders and Digimodes

For decoding non-voice analog and digital radio transmission modes, Skywave Linux contains Fldigi, JS8Call, WSJT, and JTDX applications. Weather satellite decoding is possible with SatDump, which handles APT and LRPT signal formats. Gpredict provides real-time satellite tracking and doppler shift correction data. Use the PulseAudio Volume Control application to select the best audio source and levels.

Conventional radio and video broadcast streams are also supported in Skywave Linux. SMPlayer provides global access to music, talk, news, political, and religious stations around the world. Take your swim in the ocean of truth and disinfo. Editable playlists of IPTV and IPRADIO stations are located on the internet - available through most search engines.

Usage and Installation Options

Skywave Linux is intended to run as a live environment you boot from a flash drive. However, it is now easily installable with the Calamares application! Write this great Linux system to your desktop or laptop hardware and go forth and tune in the world. It is lightning fast when fully installed on bare metal. Also, Ventoy may be used to set up a portable multiboot drive you can use for USB booting.

The live iso is packaged as a DVD image, but it is not recommended to burn an actual DVD to run any live computing environment. DVDs are far, far too slow! Use a flash drive or SSD for a portable set up; fully install to bare metal for top performance.

Apps for Coders

Python, Go, Lua, Bash, Perl, Node.js, Java, and Ruby are installed. Neovim is the editor for coding. It looks great. It is functional and streamlined for friction-free workflow. JupyterLab is also installed, which supports creation, testing, and sharing of live applications written in Python, Go, Lua, and Bash. Just do it! Make the next leap in software defined radio by writing the next generation of DSP and firmware applications. Beginners and advanced coders will all enjoy the software creation tools available in Skywave Linux.

Command Line Tools

Skywave Linux contains a plethora of efficient and fast command line tools.

• Neovim and Nano are a pleasure to program in, in part, because they are so fast.
• Browsing the web is a breeze in text mode with W3M. Navigate pages with Vim-like keys and enjoy cleaner, stripped text using the Readability utility.
• Surfraw is a search tool providing well over a hundred different websites to access for information not easy to find on the major portals. You can look for aircraft in flight by registration or ADSB hex code, find answers to computing or math problems, or even do lookups of slang phrases or rumors appearing in the news.
• TwitGrid pulls multiple Twitter feeds and displays them in Firefox. Here, it is set up in "topics." You select a topic and watch multiple feeds.
• Irssi is a terminal based internet relay chat (irc) application for anyone wanting to go "old school" in text based communication.
• lf is a fast and efficient terminal file manager. Navigate with Vim-like keys, with previews and user configurable management commands.
• fzf, ripgrep, and fd are tiny yet very effective tools for searching and organizing files or text. With these, you can reach into dozens or hundreds of files to recursively find words, phrases, code, or even terminal command history.

Technical Notes

Skywave Linux is a 64 bit x86 operating system. As of version 5, it is based on Debian's Sid branch of GNU/Linux. Skywave Linux uses the Dynamic window Manager (DWM), with a great set of patches, to provide an efficient workflow light on resources and fast.

More than two thirds, and by some measures, three quarters of humanity live in restrictive information environments, where media access is distorted or unreasonably blocked. It may be necessary for users to make encrypted network connections, which provide stronger privacy, security, and ability to circumvent censorship or geoblocking. Skywave Linux is made to continue working, anyplace and anytime, with the help of tools like Sshuttle, Wireguard, and OpenVPN client applications are installed. There is also a Tor Remote script, useful for SSH tunneling to a distant server which then connects to the internet via Tor. Skywave Linux effectively evades censorship barriers.

Acknowledgements

Skywave Linux thanks the talented developers who create Debian, Gqrx, Cubic SDR, Dump1090, Fldigi, WebSDR, and the many other components which are essential to this distribution. Skywave Linux also thanks the end users for selecting this distribution and hopes it is an asset to their radio monitoring endeavors.

Integrity and Authenticity of Skywave Linux

Great effort goes into making Skywave Linux safe and free of malware. To verify that your copy of the iso image file is authentic, undamaged, and unaltered, check the sha256sum against the official authentication document and verify the digital signature of Skywave Linux. The authentication document is available by the download link at Skywave Linux.com. Use the "Passwords and Keys" or equivalent application to check the signature. Import the Skywave Linux public key from pool.sks-keyservers.net or keyserver.ubuntu.com.

Disclaimer

Skywave Linux is provided as-is. No guarantees or warranties are applicable to Skywave Linux. Skywave Linux is an independent distribution derived from Debian GNU/Linux, but not endorsed by or affiliated with Debian or any other organizations. End users bear all responsibility for compliance with applicable regulations relating to communications monitoring.

Special Notes and Bug Fixes

See the bugfixes page.

Integrated Changes for this Version of Skywave Linux

For older changes, visit the DOWNLOADS page.

On the left, a map of KiwiSDRs and WebSDRs. On the right, SuperSDR (client for KiwiSDR) is tuned to CBC Radio, on the synchronous detector.