Horizontal Beam Width determines which of the following?

• A. Target separation
• B. Range
• C. Detection range at sea
• D. Antenna gain

Answer: (A)

Horizontal beam width is the angular width of the antenna’s main beam in the horizontal plane, and it governs azimuth resolution. When two targets sit close together in the horizontal direction, a wide beam may cover both at once, making them appear as a single target. A narrower horizontal beam width confines the energy to a smaller angular span, allowing you to distinguish two separate targets that are close in azimuth. That’s why horizontal beam width determines how well you can separate targets in the horizontal direction.

Range and detection range at sea depend mainly on transmitted power, receiver sensitivity, noise, and target properties, not on how wide the beam is sideways. Antenna gain is related to how concentrated the power is in the main lobe, which relates to aperture size and efficiency; a narrower beam can accompany higher gain, but gain isn’t defined by beam width alone.