Predicted fire (originally called ''map shooting'') is a tactical technique for the use of

artillery Artillery is a class of heavy military ranged weapons that launch munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during si ...

, enabling it to fire for effect without alerting the enemy with ranging shots or a lengthy preliminary bombardment. The guns are laid using detailed calculations and surveys to increase aiming accuracy from the first round.

Field artillery

Predicted fire aims to achieve tactical surprise when the target is to be engaged by

indirect fire Indirect fire is aiming and firing a projectile without relying on a direct line of sight between the gun and its target, as in the case of direct fire. Aiming is performed by calculating azimuth and inclination, and may include correcting aim ...

Gun laying A gun is a ranged weapon designed to use a shooting tube (gun barrel) to launch projectiles. The projectiles are typically solid, but can also be pressurized liquid (e.g. in water guns/cannons, spray guns for painting or pressure washi ...

is based on calculations of the range and

azimuth An azimuth (; from ar, اَلسُّمُوت, as-sumūt, the directions) is an angular measurement in a spherical coordinate system. More specifically, it is the horizontal angle from a cardinal direction, most commonly north. Mathematical ...

of the target relative to the gun position, without the need for ranging shots (or ''adjusting'') or even observation of the target. Ranging shots take time, and alert the enemy both to the presence and position of the guns, and to the likelihood of an attack. Predicted fire enables enemy artillery, strongpoints or troop concentrations to be struck without warning, often shortly before a friendly attack so as to leave no time for recovery, or engagement of targets hidden from observation by friendly forces. It can be used to plan any type of fire, including concentrations or the creeping barrages commonly used in

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...

.Hogg, p 32 Predicted fire was developed during World War I and became the main method of using

field artillery Field artillery is a category of mobile artillery used to support armies in the field. These weapons are specialized for mobility, tactical proficiency, short range, long range, and extremely long range target engagement. Until the early 20t ...

until the present day. The first battle in which the fireplan consisted entirely of predicted fire was the Battle of Cambrai in 1917, in which the British guns were moved into surveyed positions at the last moment, achieving tactical surprise when they commenced firing. Predicted fire requires precise surveying of the gun position and accurate maps. Ideally all firing batteries will have been surveyed onto a common survey grid. Accurate shooting needs complicated calculations including such factors as the elevation of the target and firing position, wind speed and direction,

barometric pressure Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, 7 ...

, gun barrel wear and even propellant batch and temperature. The opposite of prediction is ''reduction'', the process of calculating a target's map co-ordinates for a target registered by firing. Glossary of Royal Artillery terminology in World War 2

Anti-aircraft warfare

Predicted fire is also used by

anti-aircraft gun Anti-aircraft warfare, counter-air or air defence forces is the battlespace response to aerial warfare, defined by NATO as "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It includes surface based ...

s, using a device called a ''predictor'' or ''director'' to compute a firing solution.

Footnotes

References

* Hogg, Ian V, Barrage: the Guns in Action, Macdonald, 1971 * {{cite web , url=http://nigelef.tripod.com/index.htm , title=Artillery in World War 2—The field artillery organisation, tactics, gunnery methods and regiments of the Royal Artillery and the artilleries of British Commonwealth , accessdate=2 January 2010 A large and detailed site on Royal Artillery methods in World War 2 Artillery operation