Recently the company Stratux released a new ADS-B/UAT diplexer PCB. This is useful if you have a single antenna and want to feed two RTL-SDR dongles, with one receiving 1090 MHZ ADS-B and the second receiving 978 MHz UAT. The filter consists of a splitter and two SAW filters.
ADS-B is short for Automatic Dependant Surveillance Broadcast and is used to help track aircraft in the sky. It is transmit at 1090 MHz and the signal contains aircraft data such as the location, speed, altitude and aircraft call sign. ADS-B is utilized worldwide.
UAT is short for Universal Access Tranceiver and is transmit at 978 MHz. Like ADS-B it is used to keep track of aircraft, however UAT is only available in the USA and only for aircraft that fly below 18,000ft. It is a little cheaper and unlike ADS-B, UAT transmissions can also contain weather and traffic data.
US aircraft owners/operators that fly below 18,000ft can choose to install either UAT or ADS-B transmitters in their aircraft, so in the US a complete monitoring solution needs to monitor both 1090 MHz and 978 MHz.
Over on Reddit freelance investigative journalist Emmanuel Freudenhal has put up a very interesting post about how he is using ADS-B tracking to keep an eye on the travel habits of dictators around the world. If you were unaware, ADS-B is a signal transmitted by aircraft which contains aircraft ID info, and data such as speed, altitude and GPS location. Websites like ADS-B Exchange aggregate ADS-B data from volunteer ground stations that are running (mostly) RTL-SDR dongles. Emmanuel notes that by watching the movements of aircraft registered to dictators, it is possible to keep an eye on their travel habits.
One story that Emmanuel has written using this data is a piece on Paul Biya, Cameroon's president. His article discusses how Paul Biya is often seen in Geneva Switzerland, away on private visits. In a comment, Emmanuel notes that since his story ran, Paul Biya has almost stopped travelling to Switzerland.
Emmanuel has also been running a Twitter bot that uses ADS-B data to automatically tweet when a dictator aircraft is detected at Geneva airport. A list of known dictator aircraft is kept on a publicly accessible Excel file.
Now he is hoping to expand his tracking operation, and is asking for more people to feed the ADS-B Exchange aggregation website. ADS-B Exchange is the site recommend to feed because it is the only ADS-B aggregation website that does not censor any aircraft. Other aggregation sites such as Flightradar24 and FlightAware have come under scrutiny in the past for their willingness to upon request censor and block the tracking of military/political aircraft and private jets owned by several companies. In particular several aircraft owned by dictators are reportedly censored. However, the counter argument is that not censoring aircraft may result in ADS-B tracking eventually being made illegal, or that costly legal suites may be brought against ADS-B aggregation companies.
With a colleague, we started a project to look into the travels of dictators around the world. It's an evolution of a Twitter bot (https://twitter.com/GVA_Watcher) started a few years ago. This bot tweets every time an aircraft owned by a dictatorship lands or takes off at the Geneva airport, Switzerland. And dictators visit Geneva, a lot. There's secretive banks and good healthcare, enjoyed by Algeria's departing president or Cameroon's president Paul Biya.
We want to expand this project to all of the world's airports. See our place-holding website: https://dictatoralert.org(which will get expanded soonish). To do so, we've partnered with ADSB-Exchange, which as you probably know, is the only website that doesn't censor flights. Usually the planes owned/chartered by dictatorships don't show up on flightaware or flightradar24 (anyone can asked to be removed). Some planes also don't share their GPS coordinates (e.g. Mode S) and so they don't show up.
In addition to the Dictator Alerts, we'll also use the data to do investigations into dictatorships, human rights violation and corruption.
The idea is to allow everyone to keep tabs, so the data will be available publicly, via Twitter bots and on a dedicated website (with e.g. a page per dictatorship and per airport).
To succeed, we need a lot more antennas! So, it'd be great if you could feed ADSB-Exchange. You can do that in addition to feeding other services. See how to do it here: https://www.adsbexchange.com/how-to-feed/ If you want to feed, please contact me on [email protected], my twitter DM are open. It's quite important that you contact me before feeding, so that we also capture aircrafts that don't share their GPS coordinates.
That also means, you'll be able to see ALL of the data that you're collecting online.
What do you think? Would you be keen to participate? Any questions?
Your feedback is very welcome, i'm still learning!
Over on his YouTube channel Corrosive from the SignalsEverywhere YouTube channel has uploaded a tutorial that shows how to set up ADS-B aircraft tracking with an RTL-SDR, dump1090 and Virtual Radar Server. The decoder software is dump1090 which is a multiplatform command line tool, and Virtual Radar Server is a Windows and Linux compatible program that is used to display the data on Google maps.
ADS-B is used as a more accurate and modern replacement for traditional aircraft radar. Instead of relying on radar reflections, ADS-B simply transmits a radio signal containing plane data such as GPS location, speed, and identification codes. Other aircraft can use this data for collision avoidance, and ground control use it for traffic management. Setting up your own RTL-SDR based ADS-B receiver allows you to see and track on a map almost all the aircraft currently flying in your area.
ADS-B Receiver With RTL SDR | Tracking Aircraft In Real-time!
His initial idea was to create a flexible and open portable SDR device, however keeping the device open and built for general use meant increased complexity which quickly slowed his progress. Instead [Nathan] decided to focus on just ADS-B for his portable device as living near an airport he’d been interested in aircraft tracking since his first SDR arrived.
The device consists of a Raspberry Zero, RTL-SDR, 3.5″ IPS LCD and a battery pack for portability. For software he uses dump1090 with some custom code for the map plotting. Together with a 3D printed case and some buttons, the result is a very professional looking portable aircraft tracking device.
Hopefully Nathan will continue updating his project page so that others may replicate it on their own.
RadarBox24.com is a flight data aggregation service similar to sites like FlightAware.com and FlightRadar24.com. They aggregate ADS-B aircraft data obtained from (mostly) volunteer RTL-SDR based feeders based all over the world and use this to power their flight tracking map and flight information database.
Last year RadarBox24 came out with a specialty ADS-B RTL-SDR dongle. This is a custom RTL-SDR which contains a built in 1090 MHz tuned amplifier and filter. We have not tested this dongle yet, but we expect that the design and performance would be very similar to the FlightAware ADS-B dongles. A network analyzer report from RB24 is provided here.
These dongles can only receive 1090 MHz and do so better than a standard RTL-SDR due to the built in LNA and filter. The LNA reduces the noise figure of the dongle leading to greater sensitivity, and the filter removes any strong out of band signals that could overload and desensitize the dongle. This results in greater reception range, and more flights tracked. Please note that these dongles cannot be used as wideband general purpose RTL-SDRs due to the filtering.
ADS-B data can easily be shared to RadarBox24 with their Raspberry Pi image and RadarBox24 write that if you share data to their site, you will receive the following kickbacks:
Free Business Account while sharing (worth $39.95 /mo). This allows you to access RAW and historic flight data as well as enabling other features such as more advanced data filtering, and a weather layer.
Strong and enthusiastic Community on Whatsapp
Track your own station's flights in real-time not only on website but also on RadarBox apps
Over on YouTube icholakov has uploaded an informative video that gives an overview of the main communication modes that aircraft use from HF to UHF. In the video he also gives examples of those modes being received and decoded with an SDR.
The modes that he explains and demonstrates are VHF voice, VHF ATIS automated weather, ACARS short data messages, HF voice, HF automatic weather, HF data selective calling (SELCAL), HF data link (HFDL) and UHF ADS-B aircraft positioning.
The team at radarbox24.com recently wrote in and wanted to share some new developments including news about their recently released RadarBox XRange receiver, which is an RTL-SDR based ADS-B receiver. Radarbox24 are an ADS-B aggregation flight tracking website, similar to sites like flightaware.com and flightradar24.com.
The RadarBox XRange receiver costs $649.95 USD and is available on their store. The box appears to include a full computing unit as well as a custom RTL-SDR receiver, and a built in filter and LNA as well. It is sold as a set that includes receiver, power supply, antenna and cabling. Compared to setting up an ADS-B receiver on your own by purchasing an RTL-SDR, ADS-B LNA/Filter, Antenna and Raspberry Pi separately, the XRange is well over three times more expensive. But it may have some value as an easy to set up and ready to go ADS-B receive system. They write:
1- We have release the brand new RadarBox app for iOS and Android where data sharers are able to see what what their own stations receive using the MyStation feature.
2- We've released the brand new RadarBox XRange receiver, RTL SDR based whcih is being sold and placed all over the world to increase network coverage.
3- Our RadarBox24.com flight tracking portal reached 3 millions viewers per month and, together with our apps, is growing really fast by providing an easy way for Raspberry Pi owners or users with our XRange and Micro RadarBox receivers to share flight data with us and benefit from a free Business account.
- Link for users to install our software on their Raspberry Pi receivers and start sharing data with us (we get up to 5 new added units added to our network daily): https://www.radarbox24.com/raspberry-pi
Back in early 2016 we posted about a journalist who used an RTL-SDR to gather ADS-B data about the type of aircraft used at the world economic forum in Davos. The idea was to help highlight the vast wealth and power of the attendees by showing off their heavy use of private aircraft.
Now more recently Laurent Bastien Corbeil has published a similar article in Motherboard (a Vice News tech magazine) explaining how he tracked police and military planes at this years G7 summit which was held in Canada in early June. Laurent used an RTL-SDR Blog V3 with the small dipole antenna attached to a window to gather ADS-B data from all the aircraft activity during the summit.
ADS-B is a radio system used on modern aircraft which broadcasts the aircraft's current GPS location and other data such as aircraft identifiers. It is now used extensively by air traffic controllers as it is significantly more reliable than traditional radar. With a simple RTL-SDR it is possible for anyone to track and plot ADS-B data on a map, and this is how tracking sites like flightradar24.com and flightaware.com work.
From his collected data he was able to spot several interesting aircraft such as Canadian Air Force Chinooks, C130 Hercules', RCMP Pilatus', a military Bombardier jet, and a coast guard Bell 427. He also notes that while he was able to spot Donald Trumps Marine One helicopter with his own eyes, the ADS-B data was not present, indicating that more important military aircraft do not broadcast ADS-B for security reasons.
In the article Laurent makes estimates of the costs of operating these aircraft, and makes some guesses on the type of mission flown by some of the aircraft.