How Flight Tracking Websites Know Where Aircraft Are

Public flight maps can make global air traffic look like one seamless data source, but the picture is assembled from several technologies. Coverage is excellent in many regions and weaker in others, while some aircraft are intentionally filtered or shown with limited detail.

ADS-B is the main source for many live positions

Equipped aircraft broadcast identity, altitude, speed and position. Networks of receivers collect those messages and send them to tracking platforms.

Satellites extend coverage over oceans and remote areas

Space-based receivers can detect ADS-B signals far beyond terrestrial antenna range. That has greatly improved tracking where traditional ground networks were sparse.

Radar and multilateration can fill other gaps

Some services receive radar-derived feeds, while multilateration estimates position from the timing of transponder signals reaching several receivers. The exact mix differs by provider and country.

Schedules and flight plans add context

A position point alone does not explain origin, destination or estimated arrival. Trackers combine movement data with airline schedules, airport information and filed routes.

Displayed time can lag the real aircraft

Data processing, network delays, filtering and local regulations may introduce latency. A public map should not be treated as an air traffic control display.

Some flights are intentionally obscured

Owners, governments or data policies can limit how a flight appears publicly. Military, state and privacy-sensitive operations may therefore be absent, delayed or anonymized.

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