Category: Applications

DragonOS Updated: Now with OP25 Installed and many new YouTube Tutorials

Last month we posted about Aaron's "DragonOS" project, which is a ready to install Linux ISO aimed to make getting started with SDR software easy by providing several programs preinstalled, as well as providing multiple video tutorials. Recently he's updated the build, this time basing it on Lubuntu 18.04 allowing for Legacy and UEFI support, along with disk encryption. The OS supports RTL-SDRs as well as the HackRF and bladeRF and probably supports most other SDRs via the SoapySDR interface.

In terms of software he's also added OP25 and bladeRF support. Other programs pre-installed include rtl_433, Universal Radio Hacker, GNU Radio, Aircrack-ng, GQRX, Kalibrate, hackrf, wireshare, gr-gsm, rtl-sdr, HackRF, IMSI-catcher, Zenmap, inspectrum, qspectrumanalyzer, LTE-Cell-Scanner, CubicSDR, Limesuite, ShinySDR, SDRAngel, SDRTrunk, Kismet, BladeRF.

His DragonOS YouTube tutorial channel is also growing fast, with several tutorials showing you how to use DragonOS to perform tasks like listen to trunked mobile radios, use QSpectrumAnalyzer with a HackRF, receive NOAA APT weather satellite images, retrieve cellular network information via a rooted Samsung Galaxy S5, create a ShinySDR server with rtl_433 and how to capture and replay with a HackRF.

DragonOS running CubicSDR
DragonOS running CubicSDR

OpenEar Now Supports TETRA, DMR, POCSAG, ADS-B

Back in March we posted about "OpenEar" which was a newly released Windows TETRA decoder for RTL-SDR dongles. Back then the author "moneriomaa" noted that he planned to add several new modes. In the release that is currently available, OpenEar now supports TETRA, DMR, Pocsag, ADS-B as well as standard AM and NFM modes. We tested the software, and all modes appear to decode as advertised. In the future the author plans to add more modes such as MPT-1327 and AERO.

In the previous post we added an update noting that OpenEar appeared to be violating the GPL licence of OsmocomTETRA, and the author noted that he would remove the TETRA functionality until licencing was resolved. As TETRA decoding is back in the recent releases we assume these legal issues have been solved.

In the current release you also need to provide your own rtlsdr.dll file, which can be obtained from your SDR# folder, or directly from the Osmocom windows release (rename librtlsdr.dll to rtlsdr.dll).

Latest OpenEar Version
Latest OpenEar Version

Receiving SMOG-P and ATL-1 Nano Satellites with an RTL-SDR

Thank you to Zoltan Doczi (HA7DCD) for submitting his tutorial that shows how to receive signals from the SMOG-P and ATL-1 nano satellites which were launched via Rocket Lab back in late 2019.

SMOG-P is a Hungarian nano satellite developed by BME University. It's payload consists of an on board spectrum analyzer that is designed to measure electromagnetic pollution (electrosmog) from space, and to also monitor the DVB-T spectrum. It currently holds the title of the world's smallest satellite in operation.  ATL-1 is another Hungarian satellite this time developed by ATL Ltd. Its mission is to test a new thermal isolation material in space and to monitor the DVB-T spectrum.

To receive telemetry from these satellites you can use a Raspberry Pi, RTL-SDR, Yagi, and optionally an LNA and filter. In his post Zoltan shows how to install the SMOG-P decoder, and provides a script that automatically decodes, uploads packets to the BME University server, and archives old IQ files and packets.

We note that if you wish to receive these satellites, now is the time to do so as these nano satellites are in a very low orbit and only have an orbital lifespan of only 6-8 months total.

SMOG-P and ATL-1 Satellite Ground Station Receiver Setup
SMOG-P and ATL-1 Satellite Ground Station Receiver Setup

Radwave Updates: Browse SETI Spectrum Data on your Android Device

Back in February 2019 we first posted about Radwave, an Android SDR App for RTL-SDR dongles. It has some interesting features not found in other Apps like the ability to easily zoom, pause and rewind the spectrum at any time.

The author has decided to make use of these spectrum browsing enhancements by providing access to full SETI (Search for Extraterrestrial Intelligence) spectrum data sets which can be browsed via the app for a small fee. From a post on our forums the author of Radwave writes:

I've been developing Radwave, which is an RTL-SDR Android app for exploring the spectrum. I recently added some new functionality, allowing users to interactively explore full resolution SETI data hosted in the cloud - no SDR needed. You can see a preview of it here https://youtu.be/8ZJFzKcWejA and download it from https://play.google.com/store/apps/deta ... ve.android

This data comes from Breakthrough Listen. These datasets are quite large, and Radwave does all the bulk downloading, processing and hosting of the datasets, allowing you to easily navigate your way through the spectrum. If you find something cool, you can tag it and share it.

Currently there are three datasets available in the first bundle ($10 USD): Voyager 1 and two 'Oumuamua collections (surveys of the the first observed interstellar object in our solar system). The data is big, and is hosted in AWS. That gets pricey, so I'll be adding more collections to this first bundle as funding permits. If there are certain datasets you're interested in seeing, definitely let me know.

 

radwave intro 20200225

Starlink Doppler Reflections Caught with an RTL-SDR

Over on YouTube William IU2EFA has been uploading multiple short "meteor scatter" videos. This involves using an RTL-SDR to briefly receive distant radio stations via the RF signal reflecting off the ionized trail left by meteors entering the atmosphere. However, in a similar fashion satellites orbiting the earth can also reflect distant radio stations. 

In one of his latest videos William caught a train of Starlink satellites reflecting the signal from the Graves radar in France. To do this he uses a 10 element VHF Yagi, and an RTL-SDR running with HDSDR and SpectrumLab. In the video you can see and hear the change in frequency caused by the doppler shift.

Starlink is a SpaceX project aiming to bring ubiquitous satellite internet to the entire world. Currently 358 Starlink satellites are in orbit, and the end goal is to have 12000.

Starlink Train Detected with GRAVES Passive Radar — RTL-SDR + HDSDR | IU2EFA

Creating an APRS I-Gate and Digipeater with Baofeng and RTL-SDR

Over on YouTube ModernHam has uploaded a video showing how to create an APRS I-Gate and Digipeater with Baofeng and RTL-SDR. He also makes use of a Raspberry Pi as the computing module and an audio cable to connect the Baofeng to the audio jack of the Pi. The tutorial then consists of a walk through of the various software setup steps, and finally how to connect the Baofeng and RTL-SDR to the Pi.

If you weren't already aware, Automatic Packet Reporting System (APRS) is a digital VHF mode used in amateur radio. It allows for packets of data to be sent to receiving nodes over a local area via RF. Typical uses for it are vehicle tracking, weather station telemetry, text messages, announcements and other wireless device telemetry like high altitude balloons. An I-Gate is an internet connected node which receives local APRS RF signals and uploads them to the internet, to be seen on sites like aprs.fi. TX capable I-Gates may also broadcast to the local RF network messages from APRS transmitters on the other side of the world.

APRS I-Gate and Digipeater with Baofeng and RTL-SDR

DragonOS: Debian Linux with Preinstalled Open Source SDR Software

Thank you to Aaron for submitting news about his latest project called "DragonOS" which he's been working on while in COVID-19 lock down. DragonOS is a Debian Linux based operating system which comes with many open source software defined radio programs pre-installed. It supports SDRs like the RTL-SDR, HackRF and LimeSDR.

Aaron's video below shows how to set up DragonOS in a VirtualBox, and he has two other videos on his channel showing how to set up ADS-B reception with Kismet, and how to run GR-RDS in GNURadio. He aims to continue with more tutorial videos that make use of the software installed on DragonOS in the near future.

DragonOS 10 Installer (download in description)

Screenshot of the GR-RDS Tutorial

RTL-SDR AIS Android App Now with Waterfall Display for Frequency Offset Tuning

Thank you to Christian, author of the RTL-SDR AIS Android App for letting us know that he's updated his app and it now includes a waterfall display for tuning the AIS frequency. Tuning the AIS frequency is not required on higher end RTL-SDR dongles that come with a TCXO (Temperature Compensated Oscillator), but cheaper RTL-SDRs will have significant frequency offsets that will require the offset to be determined after a few minutes of warm up time. The easiest way to do this is with a waterfall display as that allows you to tune the frequency manually.

AIS stands for Automatic Identification System and is used by ships to broadcast their GPS locations in order to help avoid collisions and aide with rescues. An RTL-SDR with the right software can be used to receive and decode these signals, and plot ship positions on a map.

RTL SDR AIS Driver App PPM