How does ADS-B work?

ADS-B is a public signal transmitted by many aircraft. Here is what it contains — and what it does not guarantee.

What is ADS-B?\nADS-B (Automatic Dependent Surveillance–Broadcast) is a system in which an aircraft periodically broadcasts its position, altitude, speed and identifier. “Automatic dependent” means the transmission relies on aircraft data, not an independent radar measurement.\n\n## Where does map data come from?\nGround receivers and other aircraft can receive ADS-B signals. Public aggregators publish part of that data. NieboGuard uses public sources and clearly marks that coverage may be incomplete.\n\n## What ADS-B does not show\n- Not every aircraft is publicly visible.\n- Coverage depends on receivers, terrain and altitude.\n- An object missing from the map does not mean the airspace is empty.\n- A signal may be delayed, incomplete or incorrect.\n\n## Why we show it\nAs an additional information layer. It does not replace official radar, RCB Alerts, sirens or official messages.