Software Defined Radio for Global Online Listening
skywavelinux-2.3.iso (Release Date 08/02/2017):
Skywave Linux is an operating system using bleding-edge technology to access broadcast, utility, military, and amateur radio signals from almost anywhere in the world, without regard to state media controls or censorship. Skywave Linux connects to a large and growing network of state-of-the art software defined radio (SDR) servers, making it possible to experience high performance SDR operation without large antennas or setting up a station on-site. All you need to do is boot the system on a computer with internet connectivity. Skywave Linux can also operate numerous types of SDR hardware. Downloading, installing and configuring SDR software can be difficult for many computer users; Skywave Linux eliminates the hassle by including several applications installrd, configured, and ready to run.
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, use the application called WebSDR and OpenWebRX Servers to call up the best servers. A modern web browser is all one needs to enjoy clean, stable, AM / FM / SSB reception using this cutting edge technology. Servers at the University of Twente (NL) and G4FPH, Stafford (UK) are particularly good.
- OpenWebRX servers are a new type of internet accessible SDR, growing rapidly in number. Use the WebSDR and OpenWebRX Servers application to access several excellent sites around the world, such as Victoria, British Columbia (Canada), Overland Park, Kansas (USA) or Chiba, Japan. OpenWebRX is installed in Skywave Linux and capable of running RTL-SDR, Softrock, SDRPlay, and other hardware.
- RTL-SDR devices used on the local system. Just plug-and-play! CubicSDR and Gqrx are the main applications for receiving AM / FM / SSB modes. QtRadio (via the RTL-SDR controller script) offers advanced noise reduction and very high quality AM / SSB / CW reception, plus FM up to a 200 kHz bandwidth. Dump1090 (Mutability version) is for monitoring aircraft ADS-B transmissions. ADS-B mapping is available from Dump1090's built in webserver.
- 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.
- HPSDR hardware, for internet accessible receivers, is covered by QtRadio. Several servers, operated by volunteers around the world, are online 24 hours a day, and cover spectrum from LF through low VHF. Performance is excellent from these servers, and the radio configuration options in QtRadio make for a "professional grade" operating experience. To find servers, use the menu: Receiver > Quick Server List.
- 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.
For decoding RTTY, CW, PSK, WSPR, WSJT, RDS, and other digital radio transmission modes, the Fldigi, WSJT, and Redsea applications are installed. These decode audio from the local or remote receivers, or in the case of Redsea, directly tunes a local SDR and decodes data. Weather satellite decoding is possible with the very capable WXtoImg application. Gpredict provides real-time satellite tracking data and doppler corrected tuning control for Gqrx. In some cases it may be necessary to use the Pavucontrol application to select the best audio source (output from the LADSPA audio processor plugins). Trunked radio systems may be monitored using SDRTrunk.
An experimental application, cudaSDR, expands support in Skywave Linux for High Performance Software Defined Radio. It offers automatic discovery of connected HPSDR hardware and advanced operating features.
Conventional radio and video broadcast streams are also supported in Skywave Linux. Kodi Media Center provides access to thousands of music, talk, news, free-speech, and religious stations around the world. Editable playlists of IPTV and IPRADIO stations are located in the home folder.
Usage and Installation Options
Use Skywave Linux as you would use any live Linux system:
- Burn it to a DVD and run it as a boot disc (slow).
- In Windows, create a bootable USB or SD card using Universal USB Installer or YUMI.
- In Linux, create a bootable USB or SD card using Unetbootin.
- In Linux, simply install a bootloader and copy the iso file to a USB or SD card.
- Install it to the hard drive as the main operating system.
Skywave Linux is a 64 bit system, built on a base of Ubuntu 16.04 LTS, uses the Unity desktop environment, and draws on the capabilities of Ubuntu: software updating, graphics, system resource management, etc. It is the additional digital signal processing, networking, and signal decoding applications that set Skywave Linux apart from stock Ubuntu Linux. The default username is skywave and there is no password in the default system.
The radio software is largely compiled from source code and can be updated by end users with moderate computer skills, though Skywave Linux is designed for easy use by radio operators with basic computer skills. In fact, a key goal of Skywave Linux is to open the world of HPSDR and RTL-SDR operating to people who enjoy high performance radio but are not computer experts.
It may sometimes be advantageous for users to use encrypted connections which provide stronger privacy, security, and ability to circumvent censorship. For that purpose, the Bitmask, Lantern, and Psiphon applications are installed. In addition, basic PPTP and OpenVPN connections are included in the networking applet.
Skywave Linux thanks the talented developers who create Ubuntu, QtRadio, Cubic SDR, Dump1090, Fldigi, WebSDR, and the many other components necessary for 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.
Some parts of the world suffer from governance by regimes restricting the human right to freedoms of speech, including radio or electronic emedia access. If you are in such a restrictive place, and subject to punishment for listening to foreign media, military communications, or other signals available through Skywave Linux, you do so at your own risk. Be careful and do not get caught! Use a VPN to encrypt your internet activity. Shield and disguise your RTL-SDR hardware from rats and snitches. Skywave Linux, its developers and distributors, are not responsible for the monitoring activities of end users. We will never discourage accessing the network of software defined radio servers, but do encourage self-protective measures by anyone living under restrictive regulation. Skywave Linux is not endorsed by or affiliated with Ubuntu / Canonical. Ubuntu is simply used as a foundation for building Skywave Linux.
SPECIAL NOTES AND BUG FIXES
Installer crashes on versions 2.0 and earlier: Ubiquity had a bug which caused installations to fail when selecting languages and time zones. To remedy the bug, use "sudo apt update" and then "sudo apt upgrade" to freshen the running system before attempting a full installation.
Some users report "no audio" on certain hardware. In some cases it is due to the system not recognizing the hardware and loading improper audio drivers. Try the solutions well documented in the Ubuntu forums to modprobe the best audio modules. In other cases, the fault was in a too narrow device specification in the Pulse Audio configuration. In the file /etc/pulse/default.pa, look near line 46 for the code:
load-module module-alsa-sink device=hw:0,0 sink_name=processed_output
Replace it with:
load-module module-alsa-sink device=sysdefault sink_name=processed_output
Restart Pulse Audio or reboot the system. Check the audio by entering "sound Settings" and clicking the test buttons.
Users with Nvidia Video Hardware: Boot and shutdown times are longer than usual on the current 4.4.0 Linux Kernel due to Ubuntu's use of sub-optimal video drivers. Users who fully install Skywave Linux can download the proprietary drivers and realize faster speeds.
SDRPlay USERS: There is a software bug in Skywave Linux 1.6 which interferes with the configuration of Dump1090 for the SDRPlay. Please use the following shell command to correct the script and restore normal functionality. The command needs to be run only once for fully installed versions of Skywave Linux 1.6. Users booting from the iso file or DVD should run the command once per computing session before running Dump1090 on the SDRPlay:
sudo sed -i 's/\/sbin\/dump1090/\/sbin\/dump1090_sdrplay/g' /usr/local/sbin/dump1090_sdrplay/dump1090.sh
For the changelog, visit the Skywave Linux Download page.
Tags:Skywave Linux, HPSDR, GHPSDR3, RTL-SDR, Cubic SDR, CudaSDR, Gqrx, SDR Software, OpenWebRX, Linux SDR, SDRTrunk