What type of radar is commonly used by ATC?

• A. Height-finding search radar
• B. Weather radar
• C. Ground penetrating radar
• D. Phased array radar

Answer: (A)

Measuring aircraft altitude is a key task in ATC, and a height-finding radar is built specifically to obtain that elevation information. It scans the sky in the vertical plane to measure the elevation angle to a target. When you know how far away the aircraft is (range) and the elevation angle, you can compute its altitude using simple trigonometry. This makes it the type of radar historically used to provide height data for air traffic control.

Weather radar looks for precipitation and isn’t used for tracking aircraft altitude. Ground penetrating radar investigates subsurface features, not airspace. Phased array radar is a technology that can steer the beam quickly, but it isn’t defined by itself as the instrument for height information in ATC; the height data role is fulfilled by height-finding radar.