What is the function of "Yardstick" in operations?

The function of "Yardstick" in operations primarily revolves around its use in tactical air navigation, specifically as a means of ranging. In the military context, "Yardstick" applies to systems or methodologies that help in accurately determining positions or distances. This function is crucial for ensuring that aircraft can navigate effectively through various environments and coordinate with ground units.

When using A/A (Air-to-Air) tactical air navigation for ranging, it allows for enhanced situational awareness and the ability to execute maneuvers effectively in relation to other aircraft or designated waypoints. This application is vital in operations where precision navigation is required for mission success, such as in reconnaissance, air support, or combat operations.

The other options, while related to aviation and operational functions, do not specifically capture the primary role of "Yardstick" concerning navigation and ranging techniques. Therefore, the focus on A/A tactical air navigation as a means of ranging solidifies why this option aligns accurately with the established purpose of "Yardstick" within military operations.