What is the primary function of radar in navigation?

The primary function of radar in navigation is to detect vessels and land masses using radio waves. Radar systems emit radio waves that travel through the air and bounce off objects such as ships, landforms, and other obstacles. The radar receiver then interprets the returned signals to determine the position, distance, and sometimes the speed of these objects relative to the radar source. This capability is crucial for situational awareness in navigation, especially in conditions where visibility is low, such as fog, rain, or nighttime. Effective use of radar allows navigators to avoid collisions, identify safe passages, and ensure efficient route planning.

In contrast, other options represent different technologies or functions not directly related to the primary purpose of radar in navigation. For instance, measuring sea temperatures and calculating depths refer to different instruments and techniques used in oceanography rather than radar. While broadcasting distress signals is crucial in maritime operations, it is typically accomplished through radio communication systems rather than radar, which focuses on detecting and tracking physical objects.