Definition
An aircraft avionics function that receives ADS-B broadcasts from other aircraft and from ground stations. It allows the aircraft to display traffic information (TIS-B and ADS-B air-to-air) and flight information services such as weather and aeronautical data (FIS-B) directly in the cockpit.
Plain English
ADS-B In is the receiving side of ADS-B. It picks up signals showing where other aircraft are and brings in free weather and traffic information that pilots can see on a cockpit display.
Context Anchor
Pilots encounter ADS-B In when using cockpit traffic displays, portable receivers, or installed avionics that show nearby aircraft.
Derivation
Automatic — the system works on its own without pilot input. Dependent — it depends on the aircraft's own position source (usually GPS). Surveillance — watching or tracking aircraft. Broadcast — the information is sent out openly for anyone equipped to receive. 'In' simply means this is the receiving function, as opposed to ADS-B Out, which transmits.
Why Pilots Care
Provides precise real-time position data that improves traffic awareness and supports separation in controlled airspace.
Intuition Check
Do not confuse ADS-B In with ADS-B Out. ADS-B In receives information; ADS-B Out sends your aircraft’s position information to others.
Example Sentence 1
With ADS-B In, the pilot saw nearby traffic on the cockpit display well before ATC issued a traffic advisory.
Example Sentence 2
Before takeoff the pilot confirmed the ADS-B system was functioning for the flight.