Which scan type sweeps with a narrow beam to cover airspace?

• A. Raster
• B. Unidirectional
• C. Circular
• D. Linear

Answer: (D)

The key idea is how the radar sweeps its beam to cover airspace. A narrow beam provides high angular resolution, so you want a scan that moves that tight beam in a straight, continuous line across the sky. That straight-line progression—without rotating or jumping to a second dimension—lets you systematically illuminate a wide airspace corridor as you go, and you can repeat or offset lines to extend coverage as needed.

This is why a linear scan is the best fit: it describes sweeping the narrow beam along a single path to cover the area efficiently.

Raster would form a grid by moving in one direction then stepping in another, which isn’t the single-line sweep described here. Circular would rotate the beam around in circles, not a straight coverage path. Unidirectional is just about the direction of the sweep, not the pattern itself.