ATAK (Android Tactical Assault Kit) is an Android app used by some branches of the US military for visualizing geospatial information such as enemy and friendly positions, as well as any other information of interest. The civilian version of ATAK (CivTAK) was recently open sourced in 2020 and can be downloaded from the Google Play Store.
The software has a huge number of features for coordinating teams, planning operations and visualizing information. It can even network via handheld, or ham radios or a Meshtastic LoRa network if a central server and internet connection is unavailable. Of note is that their plugin page references the possibility of using a plugin that uses RTL-SDR hardware for ADS-B aircraft tracking. However, it appears that the plugin needs to be purchased from tak.gov. We suspect that in the future there will be more RTL-SDR compatible plugins available.
FlightAware is a company that specializes in distributed ADS-B aggregation, in order to produce real time maps and information about what aircraft are in the air. In 2021 FlightAware was acquired by Collins Aerospace, which is a subsidiary of Raytheon Technologies, a large US aerospace and defense contractor.
Most of the data that FlightAware obtains comes from volunteers all around the world running an RTL-SDR dongles on their Raspberry Pi based image. The dongles receive the ADS-B 1090 MHz broadcasts from aircraft which contain information about the aircraft including GPS location.
Back in 2016 they released the FlightAware ProStick, which is an ADS-B optimized RTL-SDR with onboard 1090 MHz LNA. Later in 2017 they released the Prostick Plus which improved performance in high interference areas due to the addition of a 1090 MHz SAW filter.
Their post goes into more detail about their products, and note that they are currently designing a new Prostick Plus with filter placed before the LNA instead of after. They also discuss how they are looking into higher end 12-bit ADCs for their receiver hardware, and at creating a dual channel receiver for the 978 MHz UAT band as well. They then go on to discuss the software architecture behind the ADS-B decoder they use.
Over on YouTube F4IPO has posted a video of him using a KrakenSDR and the KrakenSDR Android mapping app to quickly locate the source of a TETRA transmission at 427 MHz in France.
The KrakenSDR is our 5-channel coherent radio based on RTL-SDRs, and it can be used for applications like radio direction finding and passive radar. We successfully crowd funded the device on Crowd Supply.
In the video F4IPO shows a dash cam recording of his vehicle alongside a screen recording of his Android phone screen. He makes use of the auto-navigation feature which navigates him right to the radio transmit tower. He notes that the entire process to locate the transmitter only took about 5 minutes. At the end of the video he shows the antenna setup on his roof.
Electrical engineering magazine IEEE Spectrum has recently shared a story about how RTL-SDRs can be used for chasing weather balloons. With an RTL-SDR, antenna and appropriate decoding software, it is possible to decode the telemetry signal from weather balloons radiosondes, and track their live GPS location.
The author, Dave Schneider explains how chasing and hunting weather balloons can be a fun sport. To help with his hunt Dave uses an RTL-SDR, a directional antenna and the Sondehub Tracker website.
First Dave logged onto Sondehub Tracker which aggregates multiple weather balloon signals received by volunteer ground stations. One feature of Sondehub is that it can predict an approximate landing position of a balloon. It however cannot track a balloon right to its final landing spot as usually the ground station will loose signal when the balloon gets too low.
Knowing the approximate landing position, Dave drove out to the indicated location and then took out his RTL-SDR and directional antenna and was able to track and find the radiosonde by decoding the telemetry signal with Sonde Monitor.
IEEE Spectrum Weather Balloon hunting graphic (Image Credit: JAMES PROVOST)
DragonOS creator Aaron has recently put out a few Tweets showing that he has been successful at getting his KrakenSDR to run on a Steam Deck. The Steam Deck is a handheld gaming device made by Valve, the creators of several famous PC games and the Steam game store. It is essentially a powerful handheld computer with screen and good battery life, so it makes an excellent mobile SDR computing platform too.
Aaron notes that the output power of the Steam Desk isn't enough to power the KrakenSDR itself, but after adding an external battery pack it works well.
Compared to update rates from what I recall on the Pi, this looks to be crushing it @ 75-80 with low latency. The config page is extremely smooth and the Spectrum and DOA tabs are really responsive. @rtlsdrblogpic.twitter.com/X7IVC1AI7K
Over on the Frugal Radio YouTube channel Rob has uploaded part one of his two part series on the KrakenSDR. The KrakenSDR is our 5-channel coherent radio based on RTL-SDRs, and it can be used for applications like radio direction finding and passive radar. We successfully crowd funded the device on Crowd Supply.
In the video Rob unboxes his KrakenSDR, and explains how he will use it for radio direction finding. He shows his setup including the other required parts, like the Pi 4, and power supply, and then goes on to show the software installation process which involves burning an SD card and downloading an Android app. Next he sets up his antenna array by printing the antenna spacer and using the Excel antenna array calculator sheet.
Rob notes that Part 2 is coming in one to two weeks and will show him using the KrakenSDR in his vehicle to locate the source of a transmission.
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.
