Since mid-January 2020 the popular Linux and Mac compatible SDR program GQRX has seen a number of new code commits over on it's git repository. Some of the updates include moving to GNU Radio 3.8, new color maps, as well as various bug and performance fixes.
At the moment these updates only appear to be available on the latest git code, so to get them you'll need to install GQRX from source via the instructions on the git readme.
Also thank you to @devnulling for providing us with the screenshot posted below which shows off the various new color maps available for the FFT waterfall.
ADSBExchange is an aircraft tracking website service which aggregates ADS-B data from contributors running RTL-SDR's or similar receivers worldwide.
However, unlike other flight tracking sites such as flightaware and flightradar24, ADSBExchange sets themselves apart by proudly refusing to censor the tracking of military and private jets that have requested privacy. One area where this refusal to self-censor helps is with the "Dictator Alert" service. This is a service that automatically tracks the movements of private aircraft owned by authoritarian regimes via the ADS-B data collected and shared by ADSBExchange.
Recently ADSBExchange upgraded their web interface moving from the old Virtual Radar Server system to tar1090 which is a more fully featured open source display for dump1090. This new interface has some great features, like the ability to view the complete flight track history of any aircraft on a particular day, the ability to display only military aircraft and the ability to filter by altitude and aircraft type.
ADSBExchange.com new tar1090 interfaceViewing the historic tracks of 1-day of police helicopter activity in the new ADSBExchange tar1090 interface.
Over on Amazon we've recently seen the release of a 978 MHz UAT specialty RTL-SDR and 978 MHz tuned antenna by the flight tracking service known as AirNav RadarBox. The RTL-SDR appears to be similar to their 1090 MHz RTL-SDR version, which contains a SAW filter and LNA onboard the RTL-SDR. Due to the built in filter, this dongle will only work at the 978 MHz frequency. Like the 1090 MHz version, the dongle itself is priced at only US$14.95, and the antenna at US$49.95.
Universal Access Transceiver (UAT) is an alternative to ADS-B that is available only in the USA. It is typically used by smaller aircraft, transmits at 978 MHz, and apart from it's tracking system it has some additional advantages for pilots over 1090 MHz ADS-B, like the ability to receive alerts, weather data and radar plots. With an RTL-SDR and appropriate software these data services can also be received.
As an alternative to an RTL-SDR UAT receiver, we note that the Stratux has a hardware radio based UAT receiver available which has significantly lower power consumption. Although the receiver itself appears to be currently out of stock.
We note that we also currently have our 1090 MHz AirNav Radarbox Antenna + ADS-B optimized RTL-SDR set on sale for only US$39.95 + shipping, which is cheaper than you can find it elsewhere. Visit our store for ordering information.
The AirNav RadarBox 978 MHz UAT Optimized RTL-SDR and Antenna.New RadarBox 1090 MHz Filter and 1090 MHz & VHF Antenna single antenna.
OpenAstroTracker is a recently published open hardware 3D printed tracking mount designed to move DSLR cameras for astrophotography. The mount supports heavy long lenses, so we think that this mount could also have the ability to move long directional antennas for satellite tracking. It could also be interesting to modify it for automatic aircraft photography, similar to what we've seen in this previous post where a Raspberry Pi camera on a pan-tilt mount was used with ADS-B data from an RTL-SDR to track aircraft in the sky with the camera.
The 3D printer files are available on Thingiverse, and the mechanical and electronics build guide, and Arduino code is available on GitHub. The build seems to be quite a bit easier compared to a SatNOGS rotator which is another 3D printed open hardware rotator, but it is yet to be seen what sort of antenna sizes it could rotate.
OpenAstroTracker: Could be modified for satellite tracking.
Over on YouTube user kwon lee has uploaded a video demonstrating a replay attack against a parking barrier arm. The tools he uses are a HackRF and Portapack running the Havok firmware. A replay attack involves recording a control signal with the HackRF+Portapack, and then replaying it later with the transmit function of the HackRF. If no wireless security mechanism like rolling-codes are used, simply replaying the signal will result in the transmission being accepted by the controller receiver.
As he has access to the remote control he records the transmission that is sent when the open button is pressed on the remote. Later once outside he shows how transmitting with the HackRF+Portapack results in the barrier arm opening.
This reminds us of a previous post where we noted how a HackRF was used to jam a garage door keyfob to prevent people from leaving in the TV show "Mr. Robot".
RF Replay Attack _ Parking-Breaker via HackRFone+Portapack+havoc
At the Hackaday Supercon Michael Ossmann & Kate Temkin presented a talk called "Software-Defined Everything" where they demonstrated some applications of the "GreatFET One" interface board. Michael Ossmann is best known for creating the HackRF software defined radio which is a highly versatile and low cost open hardware/software SDR transceiver. His company Great Scott Gadgets also employs Kate Temkin who is the lead software developer who worked on their latest product called the GreatFET One.
The GreatFET One is a multi-purpose digital interface board that plugs into a PC via USB. It contains multiple digital IO pins, supports SPI, I2C, UART and JTAG serial protocols, can do logic analysis, and also has a built in ADC and DAC.
In the talk Michael and Kate show how a simple light sensor can be plugged into the GreatFET's ADC, allowing the sensor's data to be digitized and processed in GNU Radio. This results in a software defined light sensor. By analyzing the light data in the frequency domain via an FFT graph they're able to determine the refresh rate of the ceiling lights.
Later they also show how GreatFET can be combined with i2C sensors and GNU Radio to do creative things like use an accelerometer as a microphone for a guitar pickup, with audio effects like guitar clipping controlled by GNU Radio blocks.
Michael Ossmann & Kate Temkin - Software-Defined Everything
Back in early January we posted about how the popular web based SDR and RTL-SDR compatible receiver software known as OpenWebRX was officially discontinued by the original author. However, thanks to it's open source licence, code contributor Jakob Ketterl (DD5JFK) has been able to continue developing the code and is taking over as the lead developer on his own fork of the code.
Recently he released version 0.18.0 of OpenWebRX which includes a few major upgrades including the much needed shift to Python 3, and the inclusion of multiple new decoders for DMR, D-Star, YSF, NXDN, FT8, FT4, WSPR, JT65, JT9, APRS and Pocsag.
Hello fellow radio enthusiasts,
with great excitement I would like to announce the availability of OpenWebRX Version 0.18.0 as public release. This is the first release of the project in some time, and the first release since I started working on it, so I’m more than happy to bring this to you.
What’s new? Quite a lot, actually. For those that haven’t had the chance to follow the progress of the project in the past months, here’s a quick overview:
Most of the server code has been rewritten for better flexibility, stability and performance. The project is now fully based on Python 3.
Large parts of the frontend code have been updated or polished.
The new core now supports multiple SDR devices simultaneously, as well as switching between multiple profiles per SDR, allowing users to navigate between multiple bands or frequencies.
Added support for demodulation of digital voice modes (DMR, D-Star, YSF, NXDN).
Added support for digital modes of the WSJT-X suite (FT8, FT4, WSPR, JT65, JT9).
Added support for APRS.
Added support for Pocsag.
Bookmarks allow easy navigation between known stations.
Background decoding can transform your receiver into an automatic reporting station, including automatic band scheduling.
The integrated map shows digimode spots as well as APRS and YSF positions.
OpenWebRX 0.18.0 is available via the following channels:
Please check out our updated Setup Guide along with the rest of the documentation on the Wiki!
Questions, ideas, problems? Get in touch with the community at [email protected]!
Best regards and vy 73s
Jakob DD5JFK
We're so glad to see that this excellent software isn't dead in the water and is in fact thriving. We will continue to follow the Jakob's and the OpenWebRX communities' future developments. If you are interested, you can follow OpenWebRX development on the OpenWebRX groups.io forum.
If you've been following KerberosSDR development (our US$149 4 channel coherent RTL-SDR), then you'll know that one interesting experiment that you can set up with it is a passive radar. Passive radar makes use of already exiting strong transmitters that broadcast signals such as FM, DAB and HDTV.
With one directional antenna pointing towards the transmitter, and one pointing in the general direction of moving objects like aircraft, it's possible to detect the transmitted signal being reflected off the aircraft's body.From the time delay and doppler shift detected in the reflected signal, a simple distance/speed plot showing the aircraft in motion can be created. This previous post shows an example of what information you could potentially collect in a range/speed graph over time. In the past we've also used passive radar to detect vehicles and measure how much traffic is in a neighbourhood.
However, with two antennas we can only get the detected object's range and distance information. If we use four antennas (one pointing towards the transmitter, and three pointing in the direction of objects), it is possible to use beam forming techniques combined to obtain an estimated map coordinate of the object. This is possible as we then we have distance information available from the passive radar algorithm, and bearing information available from the beam forming algorithm.
Tamas Peto who wrote our open source KerberosSDR code has been working on some new upcoming features for the KerberosSDR software, and beamformed direction finding of passive radar is one of them. We note that to be clear this software is not yet released, and we still expect there to be several months before it is ready. At the moment all data was processed manually offline after collecting data with a KerberosSDR as part of this early test.
The image below shows an example of a recent measurement made from an aircraft. The red tracks show the actual ADS-B GPS coordinates of the aircraft, and the black line indicates the positional data measured from a DAB signal reflecting off the aircraft body. The orange line to the east indicates the main lobe of the three beam formed directional antennas, and the lines to the west indicate transmit towers.
The measured trajectory is only about 1-2 km off the actual one. Tamas notes that the position offset may be because at the moment altitude is not measured yet.
If you're interested in more information, Tamas created a PowerPoint presentation which can be downloaded from our Google Drive.
Passive Radar with Beamforming and Direction Finding
Other upcoming features that are planned for the KebrerosSDR code include being able to use direction finding on short bursty signals, improvements to networked direction finding and beamforming which may be useful for applications like radio astronomy and performance improvements.
KerberosSDR can be purchased from the Othernet store or Hacker Warehouse, and every purchase helps us fund development of more interesting features like passive radar beamforming!
