Category: Applications

DAB/DAB+ Decoder Software “Welle.io” Now Available on Android

Back in March of this year we posted about “Welle.io”, a DAB/DAB+ decoder that supports the RTL-SDR and other SDRs like the Airspy. It was available for Windows, Linux and Raspberry Pi 2/3.

Albrecht Lohöfener, the author of Welle.io has recently written in to announce that Welle.io is now available for Android as well. The app appears to be free, but is currently marked as beta, so there may still be a few bugs.

The only other app that we’ve seen which is capable of decoding DAB/DAB+ on Android is Wavesink. Wavesink costs $14.90 USD on the Google Play store, but there is a free trial version available with runtime limitations and no DAB+ support.

Albrecht notes that the app is fairly computationally intensive and will require an Android device with at least 4 cores and a clock speed of 1.3 GHz to run the app. He also mentions that they are also looking for any interested developers and translators to help with development of the app.

Welle.io on Android
Welle.io on Android

https://youtu.be/3qhwzORfq7k

XRIT Decoder for GOES Satellites: Supports Airspy R2/Mini and SDRplay RSP2

Over on his blog USA-Satcom has released his XRIT (LRIT/HRIT) decoder for GOES satellites. The software requires a licence and costs $100 USD. GOES-13 (East), GOES-15 (West) and the new GOES-16 are geosynchronous orbiting satellites that broadcast very nice high resolution weather images of the entire visible disk of the earth. The transmit their LRIT/HRIT signals at about 1.7 GHz at fairly weak power, which means that a good LNA and dish set up is critical to be able to receive them. A dish size of about 1 meter, or an equivalent grid or Yagi is recommended as the lowest starting point.

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

USA-Satcom’s decoder is Windows based and comes with a nice GUI. Some portions of the code are based on the Open Satellite Project created by Lucas Teske. It currently supports the Airspy R2/Mini and the SDRplay RSP2 software defined radios.

The software is not free, it costs $100 USD for the licence. To help curb illegal distribution of his software which has been rampant in the past, USA-Satcom also requests that you show some proof of a working setup which is capable of receiving the GOES signal before inquiring about the software.

If you are also interested, USA-Satcom did an interesting talk at Cyberspectrum a few months ago, and he has also recently uploaded his slides.

Screenshot of USA-Satcoms GOES XRIT decoder.
Screenshot of USA-Satcoms GOES XRIT decoder.

QIRX SDR: A New MultiMode RTL-SDR Program with Built-In DAB+ Decoder

Recently Clem from softsyst.com wrote in and let us know about their new SDR software called ‘QIRX SDR’. This is a multimode receiver currently capable of receiving AM/NFM/WFM and also DAB Plus. It supports the RTL-SDR via an rtl_tcp connection, so it can be used on a local machine, or a remote networked one. The main differentiating features that QIRX has against other multimode receivers like SDR#, HDSDR and SDR-Console etc is:

  • Dual Receiver, within the bandwidth of the frontend. This is most useful e.g. for watching two stations simultaneously in busy airband regions.
  • DAB+ Demodulator, to our knowledge the first one written in C#, allowing for recordings in very good quality (some samples provided for download).

The full list of features are quoted below:

QIRX is an Open Source Software Defined Radio, written in C#, downloadable on this site as a Visual Studio 2013 Solution, offering the following features:

  • TCP/IP Based: QIRX accepts 8-bit I/Q-Data either from TCP/IP sources or from pre-recorded files containing the I/Q-data. It is designed to cooperate with RTL-SDR dongles and the widely available rtl-tcp.exe as I/Q-data server. Both QIRX and rtl-tcp may run on the same machine or on separate ones. The rtl-tcp.exe might be started automatically without additional user actions, also when used remote via a LAN.
  • Dual Receiver: Within the selected bandwidth, e.g. 2.56MHz QIRX is able to operate two independent receivers simultaneously.
  • Squelch: For each receiver, QIRX provides a digital squelch, enabling to monitor the selected stations – when not transmitting – without annoying background noise.
  • Simplest Operating Principle: QIRX – using its AM, NFM or WFM demodulators – is purely FFT-based, with a NF lowpass filter only. This might change in a future version.
  • Scanner: QIRX provides for Receiver 1 a simple scanner, being able to scan large frequency areas. This is still in an experimental state.
  • HF and NF Spectrum: For each receiver, QIRX provides a spectrum viewer being able to show the HF and the NF spectrum. No waterfall spectrum yet. For DAB+, it shows the constellation.
  • DAB+ Receiver: QIRX provides a comfortable DAB+ receiver ( Transmission Mode I ). It is -to the best of our knowledge- the first C# based SDR providing this facility. Some standard libraries like the Viterbi decoder are used as C/C++ packages, accessed via P/Invoke.
  • File Recorder: For all demodulators, the audio output can be saved to .wav files, independently for each of the both receivers. For DAB+ this allows for high-quality audio recordings.

    Additionally, the I/Q raw data can be saved to a file. It is possible to replay recorded I/Q-data files.

QIRX SDR: A new multimode receiver with DAB+ decoding
QIRX SDR: A new multimode receiver with DAB+ decoding

A Screenshot based Meteor Scatter Detector for HDSDR

Over on our forums Andy (M0CYP) has posted about his new meteor scatter detection program which works with HDSDR and any supported SDR like an RTL-SDR. It works in an interesting way, as instead of analyzing sound files for blips of meteor scatter activity it analyzes screenshots of the HDSDR waterfall. The software automatically grabs the screenshots and determines if a signal is present on any given frequency. You can set a preconfigured detection frequency for a far away transmitter, and if the waterfall shows a reflection it will record that as a meteor.

Meteor scatter works by receiving a distant but powerful transmitter via reflections off the trails of ionized air that meteors leave behind when they enter the atmosphere. Normally the transmitter would be too far away to receive, but if its able to bounce off the ionized trail in the sky it can reach far over the horizon to your receiver. Typically powerful broadcast FM radio stations, analog TV, and radar signals at around 140 MHz are used. Some amateur radio enthusiasts also use this phenomena as a long range VHF communications tool with their own transmitted signals. See the website www.livemeteors.com for a livestream of a permanently set up RTL-SDR meteor detector (although that site does not use Andy’s software).

Andy writes that his meteor scatter detection software is still in beta so there might be some bugs. You can write feedback on the forum post, in the comments here, or contact Andy directly via the link on his website.

Andy's screenshot based meteor detection software
Andy’s screenshot based meteor detection software

Transmitting Analog TV Broadcasts with a HackRF

Over on the user submitted hackaday.io community, user marble has shared his work about using a HackRF to transmit PAL analog colored TV images with his rad1o (the rad1o is a slight variation of the HackRF One) using a GNU Radio flowgraph.

In his submission he shares a tutorial that explains the theory behind the PAL analog video standard. He explains the different components of the PAL signal, including the luma (black and white part), frame rates, and modulation. He then goes on to explain how color is encoded onto the PAL by using Quadrature Amplitude Modulation (QAM).

Finally in the files section marble also supplies us with the GNU Radio flowgraph which can be used to transmit PAL video with a HackRF.

PAL test signal transmitted with a HackRF.
PAL test signal transmitted with a HackRF.

Contributing ADS-B Data to RadarBox with an RTL-SDR and Raspberry Pi

RadarBox.com is an ADS-B aggregator which is very similar to other aggregators like FlightAware.com and FlightRadar24.com. These services use ADS-B data provided from volunteers all around the world to create a live worldwide snapshot of current air traffic. The data is then used by airlines, airports, aerospace companies, as well as enthusiasts and regular people to track aircraft and estimate arrival times.

Typically contributors to these services use an RTL-SDR combined with a Raspberry Pi as the receiver. Some sites also use their own proprietary hardware, but they seem to be slowly falling out of favor as the RTL-SDR solution tends to be cheaper and more effective.

Over on their blog RadarBox have uploaded a new tutorial that shows how you can contribute to their service using an RTL-SDR, Raspberry Pi and their new RBFeeder client software. The set up procedure is very simple as they provide a script which downloads and installs the software automatically.

On their store they also sell an ADS-B antenna and 1090 MHz preamp which may be of interest to some ADS-B enthusiasts.

RadarBox Web Interface
RadarBox Web Interface

Aerial TV: Android RTL-SDR DVB-T Decoder Officially Released

Last month we posted about Aerial TV, a new Android based DVB-T decoder that works with RTL-SDR dongles. Back then the app was still in beta testing and had a few operational bugs. Now the Aerial TV app has been officially released.

The app is based on the new Android DVB-T driver for RTL2832U devices which is written by Martin Marinov who is also the programmer of Aerial TV. The DVB-T driver is open source, and currently supports RTL2832U devices with the R820T, E4000, R828D, FC0012 and FC0013 tuner chips. Of note is that the R828D also has DVB-T2 support.

Aerial TV is free to download and test, but requires a $7.99 licence to use for more than 30 minutes. To use it you will need an OTG (On-the-go) cable adapter and an RTL-SDR dongle with antenna.

Just watch TV – no data plan or wifi connection required. Aerial TV works by picking up digital TV channels off the air with a regular TV antenna.

You will need a low cost USB TV tuner. You can grab one online for less than €10. Make sure to get an RTL2832 tuner. When it arrives, just connect the provided antenna and start watching. You may need a USB OTG cable to plug the tuner in your Android device. USB OTG cables are inexpensive and easy to find.

Note that your Android device must support USB OTG. If unsure, do a quick search online or consult your Android device manual. Also check that there is DVB-T/DVB-T2 service in your local area by doing a quick search online. Signal needs to be strong enough for Aerial TV to pick it up. For best results use an outdoor aerial.

You get free unlimited access to radio forever. You also get to watch all TV channels and experience all features of Aerial TV during the trial period for free. After the trial period ends you can make a one-off purchase and watch as much TV as you want. Remember: you can keep listening to radio even if the trial has ended!

Q: How do I find a supported dongle?
A: All major RTL2832 (rtl-sdr) dongles are supported. These dongles can be easily purchased online. Just type in “RTL2832” or “RTL2832U” in the search box of your favourite online store.

Q: What tuner do I need to watch DVB-T2?
A: If your country has DVB-T2 broadcasts (such as Freeview HD in UK) you will need a DVB-T2 compatible receiver dongle such as R828D in order to watch DVB-T2 with Aerial TV.

Aerial TV Screenshot
Aerial TV Screenshot
https://www.youtube.com/watch?v=R8QZHy26LHU

A Tutorial on Using a Raspberry Pi Zero Wireless for ADS-B Flight Tracking

Allaboutcircuits.com contributing writer Mark Hughes has recently posted a tutorial that shows how to use an RTL-SDR dongle with a Raspberry Pi Zero Wireless to track aircraft with ADS-B. As a bonus he also shows how to program and wire up a 64×64 RGB matrix screen to display currently tracked flight numbers.

The Pi Zero is one of the cheapest single board computers available, costing only $5 USD, and the wireless model with WiFi connectivity only costs $10 USD. It is powerful enough with its 1 GHz CPU and 512 MB of RAM to run an RTL-SDR and run several non CPU intensive applications such as ADS-B decoding.

The tutorial starts from the beginning by installing a fresh Raspbian image onto the Pi Zero. He then goes on to show how to install the PiAware tracking and feeding software from flightaware.com. Later in the tutorial he also shows how to collect data straight from the flightaware.com API, and also how to build and control an RGB matrix which can display live flight numbers.

It also seems that FlightAware themselves have recently released PiAware 3.5, which now directly supports the Raspberry Pi Zero Wireless.

http://www.youtube.com/watch?v=G6MwHB_jMCk