Predicted fire

The guns are laid using detailed calculations and surveys to increase aiming accuracy from the first round.

Ranging shots take time, and alert the enemy both to the presence and position of the guns, and to the likelihood of an attack.

It can be used to plan any type of fire, including concentrations or the creeping barrages commonly used in World War I.

[1] Predicted fire was developed during World War I and became the main method of using field artillery until the present day.

Accurate shooting needs complicated calculations including such factors as the elevation of the target and firing position, wind speed and direction, barometric pressure, gun barrel wear and even propellant batch and temperature.