What must always be communicated before starting a fire mission using polar coordinates?

Before starting a fire mission using polar coordinates, it is crucial to communicate the locations. This includes providing the point of origin, which is essential for accurately determining the location and direction of the target relative to the observer. The use of polar coordinates relies on a clear understanding of both the observer's position and the target’s coordinates to ensure effective and precise artillery fire.

Providing the accurate locations helps to prevent misfires, collateral damage, and ensures that the intended target is engaged efficiently. While enemy positions, fire team numbers, and current weather data are important considerations in fire missions, they do not specifically pertain to the fundamental requirement of establishing clear and precise coordinates for artillery engagement.