Back in January 2021 we posted about the release of the SATRAN product, which is a low cost automatic motorized satellite antenna rotator kit. The rotator is deigned to be used for pointing high gain directional antennas such as a Yagi or satellite dish at low earth orbit satellites which can move across the sky quickly. They also supply an Android App for easily controlling the rotator.
Recently SATRAN MK3 (version 3) has been released a few days ago and costs € 175,00 for the kit, but does not include the plastic parts which need to be 3D printed. Unfortunately the kit appears to already be sold out, but we suspect they are working on getting more kits soon. Also of note is that they are based in Sweden and cannot ship to the US or Canada.
The email announcement reads:
"There's a new Satran in town!"
I'm glad to announce the newest Satran MK3 Rotator which is now available in the shop. The former cast aluminum version has been abandoned since the production was way too time-consuming and expensive.
The new MK3 has taken all the advantages of both older versions and returned to a more open source and 3D-printable design. This cuts the price by two thirds, while still getting a really user-friendly, compact and able device.
...and there's a new app!
Some users have reported issues with their Android app crashing, so today a new version of the app (2.3) has been finished and will be available in a day or two. If you don't get an update notification automatically in your app, visit Google Play to check for the latest version.
The app also have a more extensive list of satellites and the possibility to search for a satellite by its Norad ID.
SATRAN MK3 Antenna RotatorSATRAN MK3 plastic parts that need to be 3D printed.
If you weren't aware of it, KrakenSDR is our RTL-SDR spinoff project and is a 5-channel coherent RTL-SDR that we have successfully crowdfunded for over on Crowd Supply. KrakenSDR is the successor to our previous 4-channel coherent product called the KerberosSDR. With a radio like KrakenSDR that is capable of coherence between channels, interesting applications like direction finding and passive radar become possible. You can also use it as five independent RTL-SDRs should you chose to.
We wanted to note that all units preordered through the Crowd Supply crowd funding campaign are now at the Crowd Supply / Mouser warehouse, and the majority have already been shipped out to customers!
The KrakenSDR with 5x Krakentenna's for Radio Direction Finding
Additional units for new purchasers are in a mixture of production and freighting and will be available for fulfillment as soon as we can. We are constrained by supply and production time, so if you're interested in a KrakenSDR, please get your order in so that you have an earlier place in the queue.
KrakenSDR ProductionKrakenSDR Boxes
Other Recent KrakenSDR Updates
Wiki Manual: Our Wiki manual and guide is up at https://github.com/krakenrf/krakensdr_docs/wiki. It covers topics from what you need to get started, radio direction finding theory and background, antenna array setup, KrakenSDR Web-GUI software guide, Android App guide and a Passive Radar guide.
Install Scripts, VirtualBox Images, Docker: For general vehicle based direction finding, which is the most popular application, we recommend using our premade Raspberry Pi 4 image for easy almost plug and play setup. But to ease installation on other computing devices (especially as the Pi 4 stock is non-existent at the moment due to the supply chain crisis) we've now created an automatic Linux install script and a Virtual Box image which can be run on Windows or Linux host machines. Third parties have also released a Docker container. See this page on our Wiki for more information.
Customer Feedback: We've also had some great customer feedback so far with one user submitting examples of his success in locating transmitters like a 162 MHz NOAA weather station, and various fox hunt beacons.
KrakenSDR Direction Finding with Android App
Arrow Antennas: For fixed site direction finding installs, Arrow Antennas is now shipping their 5-element dipole antenna array.
If you're interested in the latest KrakenSDR updates, please follow us on the Crowd Supply mailing list, and keep an eye out for our official krakenrf.com website releasing soon.
Back in 2017 we first posted about KYDronePilot's HDFM software which allows users to display the live weather and traffic data embedded into some HDFM signals.
If you are in the USA, you might recognize HD Radio (aka NRSC-5) signals as the rectangular looking bars on the frequency spectrum that surround common broadcast FM radio signals. These signals only exist in the USA and they carry digital audio data which can be received by special HD Radio receivers. Earlier in in 2017 a breakthrough in HD Radio decoding for SDRs like the RTL-SDR was achieved by Theori when he was able to piece together a full HD Radio software audio decoder that works in real time.
It turns out that some of these HD Radio signals run by iHeartRadio also contain other data streams such as live weather and traffic data that is consumed by HD Radio based car GPS receivers or audio head units in US vehicles. HDRadio.com also write that they can embed other data such as sports scores and emergency messages into the data stream as well.
FISSURE (Frequency Independent SDR-Based Signal Understanding and Reverse Engineering) is a recently released open source framework that runs on Linux, and includes a whole suite of previously existing software that is useful for analyzing and reverse engineering RF signals. On top of that it includes a custom GUI with a bunch of custom software that ties everything together in a full reverse engineering process.
Recently the developers spoke at this years Defcon conference, and the talk video is supplied at the end of this post. In their talk they explain the purpose of FISSURE, before going on to demonstrate it being used to reverse engineer a wireless X10 doorbell. FISSURE makes analyzing the signal easy, starting with spectrum analysis to find the signal, then signal recording, signal cropping, signal replay, crafting packets and crafting attacks.
News and developments about FISSURE can also be seen on their Twitter.
FISSURE is an open-source RF and reverse engineering framework designed for all skill levels with hooks for signal detection and classification, protocol discovery, attack execution, IQ manipulation, vulnerability analysis, automation, and AI/ML. The framework was built to promote the rapid integration of software modules, radios, protocols, signal data, scripts, flow graphs, reference material, and third-party tools. FISSURE is a workflow enabler that keeps software in one location and allows teams to effortlessly get up to speed while sharing the same proven baseline configuration for specific Linux distributions.
The framework and tools included with FISSURE are designed to detect the presence of RF energy, understand the characteristics of a signal, collect and analyze samples, develop transmit and/or injection techniques, and craft custom payloads or messages. FISSURE contains a growing library of protocol and signal information to assist in identification, packet crafting, and fuzzing. Online archive capabilities exist to download signal files and build playlists to simulate traffic and test systems.
The friendly Python codebase and user interface allows beginners to quickly learn about popular tools and techniques involving RF and reverse engineering. Educators in cybersecurity and engineering can take advantage of the built-in material or utilize the framework to demonstrate their own real-world applications. Developers and researchers can use FISSURE for their daily tasks or to expose their cutting-edge solutions to a wider audience. As awareness and usage of FISSURE grows in the community, so will the extent of its capabilities and the breadth of the technology it encompasses.
FISSURE RF Framework - Griffiss Institute & AIS Monthly Lecture + Education Series
Over on YouTube TheSmokinApe has uploaded a video showing how to use the direct sampling mode on RTL-SDR Blog V3 devices to receive HF transmissions, such as the ham bands, short wave and AM broadcast. In the video he shows how to activate direct sampling mode in SDR#, and then goes on to show reception of a few HF signals.
We note that an appropriate HF capable antenna is required to receive HF signals. The multipurpose dipole kits we sell are for VHF/UHF reception only. A simple and low cost HF antenna could just be a long wire running through your house.
Thank you to Samual Yanz (N7FNV) for submitting a guide that he's created about tracking and decoding NOAA weather satellites. The guide can be downloaded from this link as a PDF.
Currently there are three operational polar orbiting NOAA weather satellites that transmit image data in the APT format at 137 MHz. When one of these satellites pass overhead, it is possible to use an RTL-SDR with appropriate satellite antenna and software to receive the satellite weather images they transmit.
Samual's guide focuses on the software and shows how to setup Virtual Audio Cable for piping audio between programs, SDR# for receiving the signal, Orbitron for tracking the satellite and WXtoIMG for decoding the image.
Thank you to Joel Moser who has submitted news about his teams scientific research work at Soochow University in Suzhou, near Shanghai, China which makes use of RTL-SDR Blog V3 dongles in their research to replace bulky and expensive analysis equipment such as a lock-in amplifier, a vector network analyzer, or a spectrum analyzer. Their results show that an RTL-SDR can produce results as good as those more traditional pieces of equipment.
The researchers have also provided a summary video, which helps explain the science in an easier way. In a nutshell, as far as we understand it, they first use a laser optical interferometer to measure the graphene nanomechanical resonator, and then connect the output of the interferometer to the RTL-SDR, where the signal can be measured on a PC, and then easily put forward to further DSP processing in GNU Radio.
One interesting result is that they were able to recover very clear audio from the graphene nanomechanical resonator using the RTL-SDRs. This is highlighted in the video from around 4:25. Also provided via their website are two audio files demonstrating a clear reading of a Shakespeare sonnet, and a musical.
Our project is about detecting weak vibrations in nanomechanical resonators based on graphene drums. Graphene is an atomically thin membrane of carbon atoms. Graphene drums are made by suspending the membrane over an array of cavities nanofabricated in silicon oxide. Vibrations of the membrane are driven using a capacitive force at frequencies ranging from 10 to several hundreds of MHz. The detection of vibrations is done by optical interferometry, with the electrical output of our photodetector connected to a radio frequency measuring instrument. Usually, the measuring instrument is a lock-in amplifier, a vector network analyzer, or a spectrum analyzer, which are all rather bulky and expensive systems.
In our work, we demonstrate that graphene nanomechanical vibrations can be adequately measured with RTL-SDR v3 dongles. We find that the quality of our dongle-based measurements is as good as that of measurements made with a low noise spectrum analyzer, provided the driving force is not too small.
We take full advantage of your dongles by measuring the amplitude of two vibrational modes in parallel. For this, we split the output of the photodetector and connect it to two dongles. Measuring multiple modes in parallel is very valuable for nanomechanical sensing applications, as more information can be extracted compared to single mode measurements. However, this is a challenging task that requires several instruments collecting data in parallel. Here, we demonstrate that a composite of SDR dongles offers an alternative that is remarkably simple and inexpensive per frequency channel.
Finally, we show that our software-based instrument can be employed to demodulate human voice encoded in nanomechanical vibrations. For this, we drive vibrations with a frequency modulated force. As a baseband signal, we alternatively use a Chinese song performed by one of us, poetry by Shakespeare, and an excerpt from a musical.
We are now improving our measurement setup by synchronizing the clocks of several RTL-SDR v3 dongles to measure vibrational modes coherently. We are also greatly interested in employing your KrakenSDR for even better and cleaner multimode nanomechanical measurements.
A recent paper about our work can be freely accessed here:
Audio files for our demodulated nanomechanical signals can be found at the same address, but they are buried in a supplemental material (media) folder. Alternatively, the paper and the audio files can be found here:
Thank you to Sasha Engelmann for letting us know about the release of the Open-Weather community's web browser based NOAA APT decoder. The decoder allows for easy NOAA satellite decoding by allowing you to upload a wav file recording of a NOAA satellite pass, and it will decode it into an image within the browser.
The project emerged from a desire to understand the process of decoding APT audio recordings into NOAA satellite images, and a need for an accessible browser-based decoder for new practitioners during open-weather DIY Satellite Ground Station workshops.
While we were inspired by Thatcher's APT 3000, we felt accessibility, documentation and features could be expanded and improved. open-weather apt allows you to select an audio file on your computer, choose a demodulation method, add histogram equalisation and download images. The website does not store your personal data, including your location or any files you upload.
