What is the purpose of the variable range marker?

The purpose of the variable range marker is to determine the range of a moving target. This tool is particularly useful in radar operations, where tracking the distance of an object over time is critical for navigation and safety. By using the variable range marker, operators can adjust the marker to follow a target's movement, allowing for precise measurement and situational awareness.

In radar systems, distinguishing the distance to various moving objects is vital for tasks such as avoiding collisions, monitoring traffic, and ensuring accurate navigation. The ability to dynamically adjust the range marker to correspond with the target's position enhances the operator's capability to gauge the target's speed and trajectory effectively.

Other options reflect different functionalities that do not align with the variable range marker's primary purpose. For example, providing a bearing line between ships or indicating the distance between two targets are typically functions of other radar tools or measurements. Similarly, calibrating fixed range rings involves setting fixed parameters rather than adjusting for movement, which is not the focus of the variable range marker.