What is the percentage of signal power attributed to side lobes?

• A. 10%
• B. 15%
• C. 20%
• D. 25%

Answer: (B)

In the context of speed measurement devices and radar technology, side lobes refer to the signal power that is emitted outside the main lobe of the radar beam. The main lobe is where the radar's maximum sensitivity and accuracy are found, while side lobes can pick up signals from unintended areas, which may introduce errors in speed measurements.

The percentage of signal power attributed to side lobes can vary based on the specific design and calibration of the radar equipment being used. A common standard across many radar technologies places the proportion of signal power emanating from side lobes at around 15%. This value indicates that while the main lobe is primarily responsible for the accurate measurement of speed, a significant, but controlled portion of signal may still arise from side lobes.

This understanding is critical when considering how radar devices calculate and report speeds. Recognizing the influence of side lobes helps in assessing the reliability of speed measurements and underscores the importance of device calibration and optimal deployment.