Fire Direction Center

In the land-based field artillery, the field artillery team is organized to direct and control indirect artillery fire on the battlefield. Since World War I, to conduct indirect artillery fire, three distinct components have evolved in this organization: the forward observer (or FO), the fire direction center (FDC) and what is called the (the actual guns themselves). On the battlefield, the field artillery team consists of some combinations of all of these elements. In other words, there may be multiple FOs calling in fire on multiple targets to multiple FDCs and any component may be in communication with some of the other elements depending on the situational requirements.

Modern artillery batteries shoot at targets measured in distances of kilometers and miles, a hundredfold increase in range over 18th century guns. This dramatic range increase has been driven by the ongoing development of rifled cannons, improvements in propellants, better communications, and technical improvements in gunnery computational abilities. Since a modern enemy is engaged at such great distances, in most field artillery situations, because of weather, terrain, night-time conditions, distance or other obstacles, the soldiers manning the guns cannot see the target that they are firing upon. The term indirect fire is therefore used to describe firing at targets that gunners cannot see, as opposed to observed direct fire. In most cases, the target is either over the horizon or on the other side of some physical obstruction, such as a hill, mountain or valley. Since the target is not visible, these gunners have to rely on a trained artillery observer, also called a forward observer, who sees the target and relays its coordinates to their fire direction center. The fire direction center, in turn, uses these coordinates to calculate a left-right aiming direction, an elevation angle, a number of bags of propellant, and a time before exploding (if necessary) for the fuse. The fuse is then mated to the artillery projectile.

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