Why is the circular overlap in a scan pattern typically 10 degrees?

The circular overlap in a scan pattern is typically set at 10 degrees to ensure coverage of an area greater than the night blind spot. The night blind spot, which is an area where vision is compromised under low-light conditions, can lead to gaps in observation if not adequately accounted for during scanning. By maintaining a consistent overlap of 10 degrees in the scan pattern, operators can effectively fill in these gaps, ensuring that no crucial areas are missed while surveying the environment. This overlap also allows for a more seamless transition across the scanned area, supporting thorough situational awareness and reducing the likelihood of undetected threats or obstacles.

The other options do not specifically address the need for this level of overlap in relation to night vision use. Overlapping for redundancy may be useful but is not the primary reason, while depth perception can be enhanced through various means unrelated to overlap in scanning. Finally, increasing overall scan speed is not directly tied to the specific degree of overlap; rather, it is more about ensuring zones are adequately covered without omitting significant areas.