_Software Defined Radio for Global Online Listening_
Version: 4.4.0-gnome (Release Date: 2023/03/02):
Skywave Linux is an operating system using bleeding-edge technology to robustly access broadcast, utility, military, and amateur radio signals from almost anywhere in the world, including countries with restrictive internet environments. Skywave Linux is set up to connect easily to a large network of state of the art software defined radio (SDR) servers, making it possible to enjoy high performance SDR operation without putting up your own large antennas or on-site 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 can also 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.
Supported SDR Types -------------------
Several types of software defined radios are supported by Skywave Linux:
1. 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 [url=http://websdr.ewi.utwente.nl:8901/]University of Twente (NL)[/url] and G4FPH, Stafford (UK) are particularly good, for example. 2. 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 [url=http://kiwisdr.ece.uvic.ca:8073/]Victoria, British Columbia (Canada)[/url]. 3. https://www.ab9il.net/software-defined-radio/rtl2832-sdr.html">RTL-SDR devices used on the local computer system. Just plug-and-play! CubicSDR, Gqrx, and https://github.com/AlexandreRouma/SDRPlusPlus">SDRPlusPlus are the main applications for receiving AM / FM / SSB modes. https://github.com/adsbxchange/dump1090-fa">Dump1090 (FlightAware version) 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 SQL compatible database for further analysis if desired. https://github.com/TLeconte/acarsdec">ACARSDec and https://github.com/szpajder/dumpvdl2">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. https://github.com/szpajder/RTLSDR-Airband">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). 4. https://www.ettus.com/">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. 5. RemoteSDRClient connects to a network of shared RFSPACE SDRs. These are high performance radios, with advanced filtering and noise reduction software. Like the shared HPSDRs mentioned above, they require broadband internet connectivity for smooth operation. 6. SDRplay, Airspy, and BladeRF 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 SoapySDR and Gr-OsmoSDR packages.
Decoders and Digimodes
For decoding RTTY, CW, PSK, WSPR, WSJT, RDS, and other digital radio transmission modes, use the Fldigi, JS8Call, and WSJT applications. Weather satellite decoding is possible with https://github.com/martinber/noaa-apt">Noaa-apt for APT and https://github.com/dvdesolve/glrpt">Glrpt for LRPT. Gpredict provides real-time satellite tracking data and doppler corrected tuning control for Gqrx. In some cases it may be necessary to use the PulseAudio Volume Control application to select the best audio source and levels. Basic trunked radio systems may be monitored using https://github.com/DSheirer/sdrtrunk/wiki">SDRTrunk.
Conventional radio and video broadcast streams are also supported in Skywave Linux. https://www.videolan.org/">VLC Media Player provides global access to music, talk, news, free-speech, and religious stations around the world. Editable playlists of IPTV and IPRADIO stations are located on the internet - available through most search engines. There _is_ a sample radio playlist in the ~/Music folder.
Usage and Installation Options
Skywave Linux is intended to run as a live Linux environment, bootable from an iso file:
YUMI and Ventoy are both capable of creating multiboot drives, so you can Use multiple operating systems for different computing tasks. Also, they create rewritable space to hold your data files or a _casper-rw_ file for persistent settings across reboots.
It is not recommended to burn an actual DVD to run any live computing environment. It is far, far too slow! Use a flash drive or SSD. For ultimate performance, clone the environment to a regular uncompressed file system.
Apps for Coders
Python, Go, 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. Jupyter Notebook is also installed, and it supports creation, testing, and sharing of applications written in Python, Go, 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 https://gitlab.com/gardenappl/readability-cli">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. * https://github.com/nuket/TwitGrid">TwitGrid pulls multiple Twitter feeds and displays them as a broadsheet in Firefox. here, it is set up in "topics." You select a topic and watch five feeds, updated at regular intervals. * https://irssi.org">Irssi is a terminal based internet relay chat (irc) application for anyone wanting to go "old school" in text based communication. * https://github.com/gokcehan/lf">lf is a fast and efficient terminal file manager. Navigate with Vim-like keys, with previews and user configurable management commands. * https://github.com/junegunn/fzf">fzf, https://github.com/BurntSushi/ripgrep">ripgrep, and https://github.com/sharkdp/fd">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, built on a base of https://www.ubuntu.com/desktop/features">Ubuntu 20.04 LTS, with the i3 Window Manager or GNOME Desktop Environment. It is a quick and efficient computing environment. The additional digital signal processing, networking, and signal decoding applications set Skywave Linux apart from its original base distro. The default username is _skywave_ and there is no password in the default system.
It is sometimes necessary for users to make encrypted connections which provide stronger privacy, security, and ability to circumvent censorship. For that purpose, https://github.com/sshuttle/sshuttle">Sshuttle, https://www.wireguard.com">Wireguard, and https://openvpn.net">OpenVPN client applications are installed. There is also a https://bunkerbustervpn.com/tor-from-vps.html">Tor Remote script, useful for SSH tunneling to a distant server which has Tor running on it. Skywave Linux will effectively evade censorship barriers.
Acknowledgements
Skywave Linux thanks the talented developers who create Ubuntu, Gqrx, Cubic SDR, Dump1090, Fldigi, WebSDR, and the many other components which help this distribution to exist. 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 https://skywavelinux.com/docs/skywavelinux-authentication.txt">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 https://keyserver.ubuntu.com/">keyserver.ubuntu.com.
_Skywave Linux is provided as-is. No guarantees or warranties are applicable to Skywave Linux. Skywave Linux is derived from Ubuntu Linux, but not endorsed by or affiliated with Ubuntu or Canonical Ltd. End users bear all responsibility for compliance with applicable regulations relating to communications monitoring._
