Plane Finder has a global network of data feeds and antennas radars that receive data broadcast directly from aircraft for flight tracking. The primary technologies used are ADS-B and MLAT. We also show feeds from the FAA and an FLARM glider feed.
We know that this website and Plane Finder flight tracking apps are used by a huge range of people including 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
ADS-B (automatic dependent surveillance broadcast) data is used throughout the aviation industry to increase efficiency and enhance safety. This technology benefits passengers, the environment, and the global economy.
Most modern commercial aircraft broadcast their callsign, position, speed and a lot more.
The ADS-B transmissions are broadcast at 1090MHz and received by internet connected ADS-B radars located around the world.
We have 1,000’s of these receivers and data feeds across the globe sending information to our servers and are always adding more.
Our servers enhance the ADS-B data with additional information such as aircraft reg/tail number, departure airport, destination, artwork, and photos.
ADS-B operating at 1090MHz is effectively line of sight for the antenna. For low flying planes and at airports receivers are normally located very close by as terrain and building block the signals. A typical ADS-B receiver has a range of between 100 and 200 miles for high altitude aircraft with 250miles possible with a great antenna position. All receivers aren’t created equal so good quality hardware and software will usually give the best results.
ADS-B Flight Tracking – Technical Aspects
Currently, most global air traffic is managed by ground-based radar systems. ADS-B will replace these legacy systems and various mandates exist around the world designed to push forward the adoption of land and satellite ADS-B tracking.
ADS-B is a key component of the US Next Generation Air Transportation System also called “NextGen”. NextGen will change the way in which American air traffic control works.
The goals include improved safety, shortened routes, reduced traffic delays and increased fuel and time efficiency.
ADS-B greatly enhances the safety of air travel by providing not only air traffic control with real-time, consistent and visible position updates but also other aircraft equipped with ADS-B. This will enable aircraft to effectively ‘see’ each other during flight.
Relying on two avionics components ADS-B uses:
- High integrity GPS unit
- 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.
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
- Squawk number
ADS-B IN – Data into the aircraft
- Weather – via Flight Information Service-Broadcast (FIS-B)
- Information – via Traffic Information Service-Broadcast (TIS-B)
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.
The Benefits of ADS-B Flight Tracking
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:
- Safety – ADS-B will make flying significantly safer. When using this system both pilots and controllers see the same radar picture.
- Management – 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 time stamps. 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 catch 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 5 minute delayed feed from the FAA. These are the orange planes in Plane Finder.
The FAA feed covers the 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.
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.
Frequently Asked Questions about Flight Tracking
Please see our FAQ Page for answers to many of the questions that are asked frequently!
Plane Finder Flight Tracker Global Coverage
Sometimes feeds can go off to due to internet failures, power cuts or changes in circumstances from those hosting our equipment or sharing data with us.
For this reason, it is impossible to create an accurate coverage map.
If you want to become a part of Plane Finder then we will be delighted to receive your data – you can also apply to host a Plane Finder receiver if you think your location will help. Se here for more details https://planefinder.net/sharing/coverage.