ADS-B stands for what?

• A. Automatic Dependent Surveillance Broadcast
• B. Automatic Data Surveillance Broadcast
• C. Airborne Dependent Surveillance Broadcast
• D. Automatic Dependent Surveillance-Broadcast

Answer: (D)

ADS-B expands to Automatic Dependent Surveillance-Broadcast. The word “Automatic” means the system operates without manual input, using onboard sensors to determine position and other data. “Dependent” indicates it relies on the aircraft’s own navigation data rather than ground-based radar alone. “Surveillance” refers to monitoring the aircraft’s position and movements, and “Broadcast” means that information is transmitted to other aircraft and to ground stations. The hyphen between Surveillance and Broadcast shows these two functions form a single capability—the data that are surveilled are broadcast. This is the official terminology used in aviation, which is why this option is the best choice. The other forms change a key term or omit the hyphen, which doesn't reflect the standard designation.