Linear and rectangular targets require orientation in terms of direction. What else must the observer send in the third transmission of the call for fire?

In the context of fire support coordination, when an observer is transmitting the call for fire for linear and rectangular targets, it is essential to communicate not only the direction but also the target's attitude. Attitude, in this case, refers to the alignment or orientation of the target relative to a reference point, which directly impacts how artillery or other fire systems engage that target.

Providing the observer with the correct attitude ensures that the firing units can make precise adjustments to their aim, effectively facilitating accurate fire support. This is particularly crucial for linear and rectangular targets, where the precise dimension and orientation significantly influence fire plan effectiveness. While direction is a fundamental element, conveying attitude in the third transmission finalizes the necessary information for proper target engagement.

Elevation contributes to the vertical positioning of the rounds, and radius is not typically relevant for the linear and rectangular targets in this context, making them less critical in this specific scenario.