DragonOS is a ready to use Ubuntu Linux image that comes preinstalled with multiple SDR program. The creator of DragonOS, Aaron, uploads various YouTube tutorials. In his latest tutorial he shows how to install the latest version of the "Boatbod" OP25 development code for receiving P25 Phase 1 on Linux with the latest GNU Radio 3.8. In the video Aaron uses an RTL-SDR, but notes it could also work with other SDRs like the HackRF.
At the beginning of 2020 Annunaki (@StupotSinders) released his third party user interface for DSDPlus. DSDPlus is a digital speech decoder capable of decoding protocols such as P25 P1, DMR, NXDN and more with an SDR such as the RTL-SDR. As it is a command line tool, it can be a little daunting for some users, which is where the GUI comes in handy.
Recently Annunaki has released an SDR# plugin version of DSDPlusUI. This makes it so you can visualize the digital voice signals at the same time as controlling and decoding with DSDPlus. The plugin is available on the DSDPlusUI website at dsdplusui.com. To use it you will need to be using SDR# 1777 or later.
In this episode of Frugal Radio's ongoing SDR guide videos Rob demonstrates how you can use an RTL-SDR with DSDPlus to monitor DMR and NXDN digital voice radio communications. Rob writes:
With a simple Software Defined Radio (SDR) and some free or frugal software, you can monitor digital radio systems like DMR and NXDN in your area.
his video is a demonstration of how I set up DSDPlus to monitor DMR and NXDN networks, and shows how to modify the various files that help the software trunk track the system with your SDR.
More details with links to the software (DSDPlus) and hardware (1 x RTL-SDR v3) I used in this video can be found at https://frugalradio.com/monitor-dmr
f you are unsure about how trunking systems work, I suggest watching the overview at the beginning of Episode 6 - https://youtu.be/zuUTXHbUvpw
2020 SDR Guide Ep 7 : Trunk DMR & NXDN digital with DSDPlus and 1 RTL-SDR
In this episode of Frugal Radio's ongoing SDR Guide videos Rob demonstrates how he uses Unitrunker and SDR Trunk with SDRs like an RTL-SDR to monitor Public Safety networks in his area. Rob writes:
This is a video demonstrating how I use UniTrunker and SDRTrunk with Software Defined Radios to monitor multiple Public Safety networks in my area.
There is some information on how trunked systems work, and you can hear how my SDRs produce better P25 audio on a Simulcast (LSM) system than some scanners.
I use a couple of RTL-SDR v3s and an Airspy R2 in this episode.
2020 SDR Guide Ep 6 : Trunk tracking Public Safety systems with UniTrunker and SDRTrunk
Simple dPMR decoder. No external dependencies, no settings, uses SDR # audio path. Designed for listening to unencrypted dPMR channels.
To install the plugin simply copy the dll's from the zip file into the SDR# folder, then copy the line from the magline.txt text file into the plugins.xml file which can be opened with any text editor.
We note that there is also an open source version of DSD which includes a dPMR decoder which we posted about here.
Vasili, author of several SDR# plugins has recently released a new APCO P25 plugin for SDR#. The plugin is easy to use, simply tune to a P25 voice signal, and it will automatically decode it into voice audio assuming that the signal is not encrypted. If the P25 signal is encrypted, you will hear garbled unintelligible voice. The plugin does not support trunking or any advanced talk group filtering features that you might find with DSD+, Unitrunker, SDR Trunk etc.
To install the plugin, simply download the zip file from rtl-sdr.ru and extra the .dll's into the SDR# folder. Then copy the text in magicline.txt file into the plugins.xml file inside the SDR# folder. The plugin should work with any SDR supported by SDR#, including the RTL-SDR.
Elektro-L is a range of Russian geostationary weather satellites. Elektro-L1 and L2 were launched in 2011 and 2015 respectively, and Elektro-L3 was launched more recently in December 2019. Currently only Elektro-L2 and L3 are in operation. Like it's NOAA GOES, Himawari and GK-2A cousins, Elektro-L satellites beam back full disk images of the entire earth. Elektro-L2 is positioned to cover South America, Africa and Europe, whilst Elektro-L3 covers the East of Africa, Eastern Europe, Russia, Middle East, Asia and the West of Australia.
Elektro L2 and L3 Coverage from https://www.wmo-sat.info/
Recently @aang254 has been Tweeting that he has managed to get an Elektro-L decoder working. The decoder is open source and available on GitHub and Windows builds are already available. He notes that he's still working on the demodulator, but that should be released tomorrow. This decoder is great news as now Europeans now have an opportunity to receive full disk images. There is no full guide yet on how to use the decoder, but we expect that one will be released soon.
We note that according to wmo-sat.info the Elektro-L satellites transmit at ~1693 MHz, and have a 2 MHz wide HRIT and 200 kHz wide LRIT mode. So the signals should be able to be received with an RTL-SDR and appropriate LNA.EDIT: Unfortunately it seems that wmo-sat.info may have incorrect information, and that Elektro-L requires X-Band hardware to receive these images. While not totally impossible, an X-Band satellite SDR setup is a bit more difficult to put together compared to the L-band SDR setup used by GOES and GK-2A.
Published my ELEKTRO-L Decoder (early release)!
You can find it here under GPLv3, it takes synced derandomized CADUs as input, but I'll add in a demodulator tomorrow no worries!
Windows builds included already!https://t.co/Txh22PZ2cG
ELEKTRO-L 2 Decoding : Sucess! Here's a full disk pic!
Now cleaning up my decoders so they are usable by someone else... (And maybe also decode all channels to get RGB?) pic.twitter.com/X5c1YUyEOo
It may not be perfect on IR, but it works! Here are all 9 ELEKTRO-L channels (MSU-GS)!
I can upload full resolution images if someone is interested.
Decoder update published as well!https://t.co/Txh22PZ2cGpic.twitter.com/i3mFIT7alU
A few days ago we posted about two SDR related DEFCON talks which were recently released. One of the talks was about detecting fake 4G base stations with a bladeRF SDR and a tool they created called "Crocodile Hunter". It is currently compatible with the bladeRF x40 and USRP B200. The talk summary is posted below as it nicely summarizes what fake 4G base stations are and what Crocodile Hunter can do.
4G based IMSI catchers such as the Hailstorm are becoming more popular with governments and law enforcement around the world, as well as spies, and even criminals. Until now IMSI catcher detection has focused on 2G IMSI catchers such as the Stingray which are quickly falling out of favor.
In this talk we will tell you how 4G IMSI Catchers might work to the best of our knowledge, and what they can and can't do. We demonstrate a brand new software project to detect fake 4G base stations, with open source software and relatively cheap hardware. And finally we will present a comprehensive plan to dramatically limit the capabilities of IMSI catchers (with the long term goal of making them useless once and for all).
The Crocodile Hunter software is apparently a little difficult to install and get running, so Aaron who runs DragonOS YouTube tutorial channel has uploaded a video documenting how to install and configure the software. The tutorial assumes that you are the running the latest DragonOS image which already includes a lot of the prerequisite software, and in his example he uses a USRP B205mini-i SDR.
