Definition
A surveillance system in which ADS-B position reports broadcast by aircraft are received by satellites in low Earth orbit rather than by ground stations. The satellites relay the data to air traffic control, providing aircraft tracking in areas where ground-based ADS-B coverage is impossible or impractical, such as oceanic airspace, polar regions, and remote terrain.
Plain English
A way of tracking aircraft using satellites instead of ground antennas. The aircraft sends out its position the same way as normal, but satellites pick up the signal — so controllers can see aircraft over oceans and remote areas where there are no ground receivers.
Context Anchor
Seen in air traffic control and surveillance discussions, especially for oceanic, remote, or other areas with limited ground receiver coverage.
Derivation
ADS-B stands for Automatic Dependent Surveillance-Broadcast — automatic because the aircraft sends position reports without being asked, dependent because it relies on the aircraft's own navigation system, and broadcast because the signal goes out to anyone listening. Space Based simply means the listeners are satellites instead of ground stations.
Why Pilots Care
Enables continuous aircraft tracking and ATC services on long overwater routes, reducing separation minima and improving safety where radar is unavailable.
Grounding Statement
Picture an aircraft crossing the ocean: instead of a ground station hearing its position signal, a satellite overhead receives it and passes it along.
Intuition Check
Space based does not mean the aircraft is navigating from space or flying in space. It means satellites in space are receiving the aircraft's ADS-B position broadcast.
Example Sentence 1
Thanks to Space Based ADS-B, controllers can now track our flight across the North Atlantic continuously instead of relying on hourly position reports.
Example Sentence 2
Space Based ADS-B now allows ATC to provide radar-like services over the Pacific where ground stations do not exist.