What does ADF stand for?

The term ADF stands for Automatic Direction Finding, which is a navigational aid commonly used in aviation to determine the direction to a station transmitting a radio signal. This technology involves the use of a radio receiver that can detect and interpret signals from ground-based beacons or transmitters. The ADF system includes a rotating antenna that will point towards the signal's source, effectively indicating the bearing to the station.

The correct answer encompasses the core function of the ADF system, highlighting its automatic capabilities that facilitate smooth navigation for pilots by continuously providing real-time directional information without manual intervention. This allows pilots to focus on other critical flight management tasks, enhancing overall situational awareness.

The other options, while they contain some relevant terms, do not precisely represent the widely accepted definition of ADF in aviation. For example, "Averaged Directional Finder" and "Advanced Directional Finder" do not accurately reflect the technology's functionality or standard terminology used in the industry. "Automated Directional Finder" is somewhat similar but still does not capture the precise meaning that "Automatic Direction Finding" conveys, particularly in the context of its application in aviation navigation.