How Plane Finder tracking works

We know that this website, the Plane Finder flight tracking apps and our underlying data are used by a huge range of people including airlines, aviation professionals such as pilots and ground crew, by plane spotters and aviation enthusiasts, and by anyone who just wants to track a friend or is curious about the planes overhead – But how does it work?

ADS-B Flight Tracking

Plane Finder is built on a core technology used by the aviation industry for flight tracking

The technology is called Automatic Dependent Surveillance – Broadcast (ADS-B) and is used to improve aircraft efficiency, manage aircraft fleets and enhance safety. This technology benefits passengers, the environment, and the global economy.

Most modern commercial, and more recently privately owned aircraft, broadcast their callsign, position, speed and a lot more. In order for this data to appear in Plane Finder we operate our own bespoke global network of ADS-B receivers and data feeds.

Plane Finder Radar

Plane Finder Radar

A bespoke global network of ADS-B receivers

An example of this is our own high-performance GPS enabled ADS-B receiver called the Plane Finder Radar. We have thousands of these receivers and data feeds across the globe sending information over the internet to our servers and we are always adding more too!

Plane Finder Radar Specs

How the ADS-B signal works

How the ADS-B signal works

This diagram shows the path an ADS-B signal takes from the aircraft to your Plane Finder apps and the website.

Enhancing the data

More than just ADS-B data

Our servers enhance the ADS-B data with additional information such as aircraft registration/tail number, departure airport, destination, artwork, and photos. In addition to ADS-B data we are also able to plot the positions of aircraft that do not transmit their GPS coordinates.

We do this via an enhanced form of triangulation called Multilateration (MLAT). Using our GPS enabled receivers we are able to provide very high levels of data accuracy for such aircraft. In Plane Finder we also show feeds from the FAA and a FLARM glider feed.

Enhancing passenger safety

The effect of MH370

Following the dreadful loss of Malaysian Airlines flight MH370 it was clear that even the local mandates were not enough and more could be done to enhance passenger safety across the globe.

The global aviation community quickly came together following the disappearance of the aircraft to specify the Global Aeronautical Distress and Safety System (GADSS) concept of operation. This is now an operational requirement and has changed how airlines track their fleets. Here at Plane Finder we are proud to support the airlines with this work.

ADS-B Flight Tracking

Technical aspects

The technicalities of the ADS-B technologies are described in more detail below:

ADS-B Requires

Two core avionics components on board the aircraft.

  • High integrity GPS
  • Data link unit (operating at 1090 MHz - modified Mode S transponder)

What is Mode S?

All aircraft carry units within their avionics system called transponders (transmitter and responder). These transponders, at the most basic level, emit a four digit signal that can be controlled via a panel on the instrument panel.

Mode S transponder

These four digits are assigned by air traffic control. On the radar screen, the controller can see the four digit code alongside the radar return of the aircraft. This enables them to identify the aircraft. The signal is received and ‘interrogates’ the transponder. That number is then returned and known as a ‘Squawk’. Short for ‘selective’ mode, Mode S transponders allow more information to be sent when the air traffic control radar interrogates the transponder. It sends information on altitude, callsign and squawk code which also enables the Airborne Collision Avoidance System (ACAS) and ADS-B systems to function.

How does ADS-B work?

Simply put, ADS-B uses the avionics within an aircraft to communicate with GPS satellites in orbit and transmit data about:

ADS-B OUT (Data from the aircraft)

Includes the following and more:

  • Callsign
  • Altitude
  • Heading
  • Position
  • Squawk number
  • Speed
ADS-B In (Data into the aircraft)

Includes the following and more:

  • Weather – via Flight Information Service-Broadcast (FIS-B)
  • Terrain
  • Information - via Traffic Information Service-Broadcast (TIS-B)
  • Traffic

This data is then received and decoded by other aircraft equipped with ADS-B avionics and ground receivers. These ground receivers then display this information to air traffic controllers through a display. From this information, they can provide vectoring instructions and organize the skies with more accuracy and more reliable information. Additionally, other aircraft equipped appropriately can also see the same information providing them with a very good early warning system enhancing their own situational awareness.

ADS-B Flight Tracking

The Benefits

The ADS-B system makes flying drastically safer predominantly by allowing surrounding aircraft to be able to see other aircraft as well as several other benefits:


ADS-B will make flying significantly safer. When using this system both pilots and controllers see the same radar picture.


The accurate data enables better decision making by ATC and pilots. This, in turn, will lead to savings in journey time and fuel.

Both IFR (Instrument Flight Rules) and VFR (Visual Flight Rules) flights benefit from the system giving:

  • Increased safety with controlled separation in non-radar airspace
  • More accurate and readily available information can be provided to VFR flights

Some of the biggest benefits will be to the Air Traffic Control Officers that manage the aircraft flying within controlled airspace are:

  • Increased efficiency of traffic flow
  • Merging and spacing information
  • Increased level of information
  • A more consistent level of radar returns
  • Alleviates some pressure by allowing improved in-cockpit information to pilots

In addition ADS-B data can also be received in-bound (ADS-B IN) by suitable equipped aircraft. This will provide additional resources to the pilot including:

  • Weather – Through information broadcasts, aircraft can receive weather reports, through Flight Information Service-Broadcast (FIS-B), providing more information to the pilot about surrounding weather.
  • Terrain – The system also provides pilots with a terrain overlay, again increasing safety.
  • Information – ADS-B also allows aircraft and their pilots to receive NOTAMs (Notice To AirMen) and TFRs (Temporary Flight Restrictions) via Traffic Information Service-Broadcast (TIS-B).
  • Traffic – ADS-B will allow the pilot to view information on surrounding aircraft. This includes callsign, altitude, heading, speed, and distances.

MLAT Flight Tracking

Many smaller and older commercial aircraft along with most general aviation planes do not have full ADS-B. This means that we do receive some data but crucially not the GPS position.

At Plane Finder, we overcome this by using Multilateration (MLAT). This is a navigational technique that involves some pretty complicated mathematics using known receiver locations and accurate timestamps. To make this work we need three or more receivers running our client software seeing the aircraft simultaneously. We can then plot the position in Plane Finder.

Federal Aviation Administration (FAA Feed)

Not all aircraft are fully ADS-B equipped. In locations such as Europe and Australia, the implementation of ADS-B is well advanced and the majority of aircraft use ADS-B. North America is behind currently but is catching up as the US NextGen ADS-B equipage project continues to develop up to, and beyond, the 2020 mandate.

Where we do not have ADS-B or MLAT coverage for an aircraft in North America we will supplement this using a feed provided by the FAA. The FAA feed covers US and Canadian airspace including bordering areas of the Atlantic and Pacific Oceans.

FLARM Feed (Gliders)

It is not practical to install ADS-B in gliders due to constraints of cost, weight, and power. FLARM has been developed as a situational awareness tool for glider pilots. It is also sometimes used in some small planes and helicopters. The technology has short range and operates at a frequency of 868MHz. Plane Finder take a centralised FLARM feed.

Blocked Aircraft

At Plane Finder, we realise that we have a responsibility to do the right thing. We aim to deliver the benefits of live flight tracking whilst working hard to ensure that our live feeds do not include data that could compromise national or regional security. We actively review the aircraft that we are tracking and consider all requests to block aircraft from our systems for security reasons.