Over on YouTube channel 'TAKEAPART' has uploaded a short video showing how he tracks aircraft via an RTL-SDR Blog V3 dongle and his car's Android head unit. The head unit is capable of running the ADS-B Radar App available on the Google Play store.
Once the app is installed, it's a simple matter of plugging in the RTL-SDR Blog V3 unit and running the app to start tracking aircraft.
Back in 2022 we first posted about adsb_deku and radar-tui, a TUI (terminal user interface) for displaying ADS-B aircraft locations with an RTL-SDR receiver. A terminal user interface means that no desktop GUI is required, instead, the map and aircraft are drawn in the terminal window using just text characters.
adsb_deku and radar-tui are based on the open-source ratatui library. Recently, Orhun, one of the maintainers of ratatui wrote in and wanted to share a YouTube video he created demonstrating radar-tui in action. In the video, Orhun explains the RTL-SDR, shows how to set up radar-tui, and shows a demo of it in action.
If you're interested in this type of application, another similar terminal based ADS-B UI is coole-radar which we also posted about previosuly in 2019.
Daniel Estévez has recently posted on his blog about how he uses a LimeSDR to record and analyze the DME signal used by aircraft. DME or Distance Monitoring Equipment is a radio navigation technique sometimes used by aircraft.
The concept behind DME is simple: the aircraft broadcasts a signal pulse, and a ground station receives and repeats the pulse back at another frequency. The aircraft receives the return pulse, and from the time it has taken to receive that return pulse, the distance to the ground station can be determined. The frequencies used are between 960 MHz and 1215 MHz, and the aircraft and ground station pulses are always spaced apart by 63 MHz.
In his post, Daniel explains how he records the two signals spaced 63 MHz apart using his LimeSDR. Recording this large bandwidth has some challenges since typically the LimeSDR only supports a bandwidth of 61.44 MHz, which is too small for the 63 MHz spacing. However, Daniel explains in his post how he got around this limitation by using the two RX channels on the LimeSDR, sampling at a higher 80 MSPS sample rate, and then using the LimeSDR DSP to downconvert and decimate each DME channel to 2.5 MSPS, making the final sample rate small enough to be sent over USB.
The rest of the post details his experiments, analysis, and results when receiving the two DME channels through GNU Radio.
Over on YouTube Matt from the Tech Minds YouTube channel has tested out NooElec's new 'FlyCatcher', which is an RTl-SDR ADS-B hat for the Raspberry Pi. The FlyCatcher has two RTL-SDRs built into it, each with it's own LNA and SAW filter. One SAW filter is tuned for 978 MHz UAT, and the other for 1090 MHz ADS-B.
The device also has buttons that allow you to bypass the LNA stage, and just use filtering, in case you have an external LNA. They appear to be using the Qorvo TQL9063 LNA chip, which has a built-in bypass.
In the video Matt tests out the FlyCatcher, but only on 1090 MHz as 978 MHz UAT is not used in his country. He shows how to set up the software on the Raspberry Pi and then shows some results.
Jack Sweeney is a student who operates various social media and websites dedicated to tracking the private jets of celebrities and notable persons. In the past he's drawn the ire of Elon Musk who banned his @ElonJet account in 2022 which used to provide live updates on the location of Elon Musk's private jet. These days he operates the @ElonJetNextDay account which tracks Elon's jet with a 24 hour delay on X, but continues to track the jet live on other platforms.
Recently the legal team for global superstar Taylor Swift threatened legal action against Jack Sweeney for running the various social media accounts that track her private jet including @SwiftJetNextDay on X with a 24 hour delay, or live on alternative platforms like Mastodon. Swift's legal team claim Sweeney's live tracking accounts pose an “imminent threat to the safety and wellbeing” of Swift.
Jack notes that he makes use of legal live ADS-B flight data from public data aggregators like Airplanes.live and AirFramesIO. ADS-B data is most commonly provided from contributors with RTL-SDR dongles running on Raspberry Pi single board computers.
The FCC does not prohibit the collection of unencrypted radio signals such as ADS-B and ACARS. This is done by thousands of feeders who give data to websites like @live_airplanes, TheAirTraffic, @AirframesIO, and ADSBexchange.
— Jack Sweeney (@Jxck_Sweeney) February 7, 2024
Even without Sweeney's social media accounts anyone can legally look up this live public flight data data, or even receive it themselves directly from the aircraft if they are close enough. Although a point can be argued that the social media accounts run by Sweeney make it significantly easier for this information to be obtained and shared by anyone.
Over on the Tech Minds YouTube channel Matt has posted a video tutorial that shows how to build a cheap quarter wave ground plane antenna tuned for 1090 MHz. This is the frequency of ADS-B (Automatic Dependent Surveillance–Broadcast), which is a signal broadcast by aircraft that can be used to track their GPS location.
The antenna is created from an SMA chassis mount socket, one copper wire for the receiving element, and four copper wires for the ground plane. They are soldered directly onto the socket. An LNA is added to improve reception.
Over on his YouTube channel Tall Paul Tech has uploaded a video that demonstrates the FM (frequency modulation) capture effect. Apart from the costs and difficult logistics to change from AM to FM worldwide, the FM capture effect may be one additional reason as to why aircraft still choose to use AM modulation for communications instead of FM.
The FM capture effect is a phenomenon that occurs when two FM transmitters transmit on the same frequency at the same time. What will happen with FM is that the stronger of the two transmissions will be the only one heard, with the weaker one totally muted. This is in contrast to AM where both signals can be heard, albeit garbled like two people talking at the same time.
With aircraft this is important as for example if some aircraft accidentally leaves a blank transmission open, another aircraft can still transmit on top of the blank transmission and still be heard. Or allowing air traffic control to hear if multiple aircraft are trying to transmit at once, and handle communications appropriately based on urgency. The disadvantage is that without the capture effect, AM is more prone to interference from interference and atmospheric noise like lightning.
In his demonstration Paul uses two HackRF's with their clocks linked and an RTL-SDR to simulate two transmitters and a receiver.
Aircraft transmit multiple types of radio signals, including ADS-B and VDL2. ADS-B (Automatic Dependent Surveillance-Broadcast) is an air traffic surveillance technology that enables aircraft to broadcast their GPS position and other data. VDL2 (VHF Data Link Mode 2) is a digital VHF signal, allowing pilots to exchange text information with ground controllers and/or airline ground support. VDL2 is not designed to provide real-time positional data like ADS-B; however, positional information is often broadcast, and the VHF signals can propagate over longer distances.
Giuseppe (IT9YBG) was curious to see if he could receive and plot both signals together on a map using PlanePlotter. His setup consists of a Raspberry Pi 3 running with RTL-SDR Blog V3 dongles and a Windows PC running another RTL-SDR. The dumpvdl2 software is used to receive the VHF VDL2 signals, and RTL1090 is used for receiving ADS-B signals. Both output data to PlanePlotter, where the VDL2 messages can be read.
He also added the "Flight controls on RTL 1090XHSI" software, which allows users to view a simulation of an aircraft cockpit, using real-time ADS-B data from the RTL-SDR.
