Which are three sensor types used in ADA systems to detect air threats?

• A. Ground-based surveillance radar, tracking radar, and electro-optical/infrared (EO/IR) sensors
• B. Ground-based surveillance radar, weather radar, and lidar sensors
• C. Acoustic sensors, tracking radar, and infrared cameras
• D. Satellite-based communication sensors, radar altimeters, and EO/IR sensors

Answer: (A)

Air defense relies on a layered sensor network that combines broad detection, precise tracking, and positive identification. The trio of sensors in the best answer fits that workflow: ground-based surveillance radar provides wide-area detection to alert you to approaching targets, while tracking radar takes over to maintain an accurate path of the target—giving reliable range, bearing, and speed data for engagement decisions. Electro-optical/infrared sensors contribute a visual/IR view that allows visual confirmation and identification, useful for distinguishing threats from friendly or non-threatening activity, and they can operate effectively when radar is challenged by clutter or weather. Together, these three sensor types cover detection, tracking, and identification in a practical ADA system.

Other sensor options mix in technologies that aren’t standard for detecting air threats in typical ADA setups—weather radar, lidar, acoustic sensors, satellite-based sensors, and radar altimeters don’t provide the same combination of broad detection, continuous tracking, and positive identification needed for air defense.