In the past, we have detailed how we track flights with ADS-B and MLAT, but that is just the beginning of a long journey to displaying a flight on our site and in our apps. In this post we’ll bring together a few of our past posts and walk through how planes flying overhead turn into icons on your screen.

ADS-B

For flights being tracked via ADS-B, the aircraft first acquires position information from GPS satellites. That information is fed from an onboard computer to the ADS-B equipped transponder. A radio signal sent by the transponder is then received by one of our ground stations and transmitted to our servers.

Click here for a more in-depth discussion of how we track flights with ADS-B

MLAT

For flights not equipped with ADS-B, we use Multilateration (MLAT). The data we get from flights without ADS-B is just a ping. If a ping from the same aircraft is received by at least four of our receivers, that data is sent to our FR24 computers for MLAT processing. By using complex mathematical formulas we are then able to determine the aircraft’s location, direction, and speed.

Click here for a more in-depth discussion on how we track flights with MLAT.

Turning Data into Information

At this point the data we have are the identity of the aircraft, the location of the aircraft, how fast it is going, and the direction it is headed. We need to add context if that data is going to be useful to our users. Once we have data on an aircraft, we fill in the missing pieces before displaying the flight on our site. We merge the ADS-B and MLAT data with airline schedules, route data, and data from the US Federal Aviation Administration to paint a complete picture of live air traffic around the world. And we do all of this in more-or-less real time.