Flightradar24 has become a popular site in recent times. First, many wanted to track what happened over Ukrainian airspace after the Russian invasion of Ukraine in late February caused the diversion of hundreds of flights. And earlier this month, millions followed the visit of Nancy Pelosi, the Speaker of the US House of Representatives, to Taiwan. According to CNN, before Pelosi’s flight, the record for the most tracked flight on Flightradar24 belonged to Russian opposition leader Alexei Navalny’s return trip to Russia. His flight in January of 2021 was tracked by 550,000 people. Navalny was returning to face imprisonment.
Flightradar24, based in Sweden, relies on 34,000 receivers around the world to pick up aircraft signals. This data is forwarded to a central network and combined with data on flight schedules and aircraft information.
As a result, the website and its mobile apps display on the screen almost every aircraft that is in the air at any given time, along with some information about its flight. All this is made possible by the automatic dependent surveillance technology, or ADS-B, used by most modern aircraft.
What is ADS-B?
Initially, this transmission technology was designed to allow Flight Operations managers to locate aircraft with greater accuracy than traditional microwave radars allow. In addition, pilots can also see all traffic.
ADS-B is a relatively complex and sophisticated system that allows pilots to get the latest updates on weather and terrain conditions, or other information. ADS-B Mode-S regularly transmits (about once per second) GPS location data (latitude, longitude, altitude), as well as speed (including vertical speed), the aircraft’s unique “heading” and flight number over the 1090 MHz channel.
All this data is sent over an unencrypted channel and can be accessed by anyone: all that is needed is basic amateur radio skills to obtain a 1090 MHz antenna and set up a simple radio receiver.
The service has a web interface, as well as free and paid mobile applications. The web interface is more advanced: it offers advanced search capabilities based on several parameters: flight number (IATA or ICAO), aircraft registration number, squawk code, an airline name or aircraft model.
The first @BoeingAirplanes 787 for @lufthansa is on its way home to @Airport_FRA. https://t.co/b3VWqufyhk pic.twitter.com/Apqhxy2COj
— Flightradar24 (@flightradar24) August 30, 2022
When searching by a flight number, the user can view the aircraft’s position in real time and, in the case of completed flights, detailed statistics, including flight parameters at any point along the route. It is possible to search for the types of aircraft used for a given flight.
When it comes to following an aircraft, it is possible to use the usual “aircraft moving on the map” mode, 3D mode or enjoy the “cockpit view”. There is no live video streaming from the cockpit; the image is compiled from satellite terrain images projected from the current altitude of the aircraft.
As for mobile apps, the service is only fully functional on paid versions compatible with Android, iPhone, iPad and even Windows Phone platforms. The free version is quite limited in terms of search capabilities. What is unique for mobile apps is that they offer augmented reality.
When a plane appears in the sky, a device’s camera can be aimed at it and the device will display the image of the plane and all the in-flight data. In practice, this does not always work correctly: it is quite difficult to keep the aircraft moving within the frame, and the data used to identify the aircraft based on its location is not always accurate: the geolocation data is obtained from the smartphone’s GPS module, with correction from the built-in accelerometer and compass.
