Which factor most degrades bearing accuracy?

• A. Large antenna beamwidth
• B. Very narrow beamwidth
• C. Precise boresight alignment
• D. High processor calibration

Answer: (A)

Bearing accuracy in radar is limited by how precisely the antenna can resolve angle, which is determined by the antenna’s beamwidth. A large beamwidth means the main lobe spans a wide angular range, so the target’s true direction can lie anywhere within that span and the measured bearing becomes uncertain—often on the order of the beamwidth itself. In other words, the angular ambiguity within a wide beam degrades how accurately you can say where the target is relative to your boresight.

By contrast, a narrow beamwidth tightens the angular constraint and improves bearing accuracy, provided the boresight is properly aligned and the system is well calibrated. Precise boresight alignment reduces systematic bias in bearing estimates, and good processor calibration minimizes processing errors. So the factor that most degrades bearing accuracy is having a large antenna beamwidth.