Editing Artillery (section)

==Modern operations==
[[File:ATAGS Howitzer.webm|right|thumb|[[DRDO Advanced Towed Artillery Gun System|ATAGS]] showcasing towing, turning and firing of rounds]]
[[File:AMX AuF1, 40e régiment d'artillerie, Implementation Force, 1996.jpg|thumb|Two French Army Giat [[GCT 155mm]] (155 mm AUF1) Self-propelled Guns, 40th Regiment d' Artillerie, with IFOR markings are parked at Hekon base, near Mostar, Bosnia-Herzegovina, in support of Operation Joint Endeavor]]

List of countries in order of amount of artillery (only conventional barrel ordnance is given, in use with land forces):{{Sfn | Hackett | 2010}}

{| class="wikitable sortable" style=text-align:right;
|+
! Country
! scope=col class=unsortable | Number
! scope=col class=unsortable | Ref
|-
| Russia || 26,121{{spaces|1|en}} || {{Sfn | Hackett | 2010 | p = 223 | ps =.  The number given is for Land Forces only. Naval Infantry and Coastal Defense forces, Federal Border Guard Service, and Interior Troops use an additional 500+ ordnance pieces.}}
|-
| North Korea || 17,900+ || {{Sfn | Hackett | 2010 | p = 412}}
|-
| China || 17,700+ || {{Sfn | Hackett | 2010 | p = 400}}
|-
| India || 11,258+ || {{Sfn | Hackett | 2010 | p = 360}}
|-
| South Korea || 10,774+ || {{Sfn | Hackett | 2010 | p = 414}}
|-
| United States || 8,137{{spaces|1|en}} || {{Sfn | Hackett | 2010 | p = 33 | ps =.  The total is composed of 6 270+ ordnance used by the US Army, Army Reserve and National Guard with 1 867 used by the USMC.}}
|-
| Turkey || 7,450+ || {{Sfn | Hackett | 2010 | p = 165}}
|-
| Israel || 5,432{{spaces|1|en}} || {{Sfn | Hackett | 2010 | p = 255}}
|-
| Egypt || 4,480{{spaces|1|en}} || {{Sfn | Hackett | 2010 | p = 248 | ps =.  Syria, Egypt's strategic partner in the past wars against Israel, uses 3 440+ artillery pieces, and is the 11th ranking artillery user in the World.}}
|-
| Pakistan || 4,291+ || {{Sfn | Hackett | 2010 | p = 368}}
|-
| Syria || 3,805+ || {{Sfn | Hackett | 2010 | p = 368}}
|-
| Iran || 3,668+ || {{Sfn | Hackett | 2010 | p = 368}}
|-
| Algeria || 3,465{{spaces|1|en}} || {{Sfn | Hackett | 2010 | p = 368}}
|-
| Jordan || 2,339{{spaces|1|en}} || {{Sfn | Hackett | 2010 | p = 368}}
|-
| Iraq || 2,300+ || {{Sfn | Hackett | 2010 | p = 368}}
|-
| Finland || 1,398{{spaces|1|en}} || <ref name="HS">{{cite web | type= news analysis | title = In a changing world, Finland's artillery stays the same | url= http://www.hs.fi/english/article/NEWS+ANALYSIS+In+a+changing+world+Finland%E2%80%99s+artillery+stays+the+same/1135238365526 | access-date= July 24, 2013 | archive-date= January 22, 2013 | archive-url= https://web.archive.org/web/20130122064517/http://www.hs.fi/english/article/NEWS+ANALYSIS+In+a+changing+world+Finland%E2%80%99s+artillery+stays+the+same/1135238365526 | url-status= dead}}</ref>
|-
| Brazil || 900{{spaces|1|en}} || {{Sfn | Hackett | 2010 | p = 368}}
|-
| Cameroon || 883{{spaces|1|en}} || {{Sfn | Hackett | 2010 | p = 368}}
|-
| Morocco || 848{{spaces|1|en}} || {{Sfn | Hackett | 2010 | p = 368}}
|-
| Hungary || 835{{spaces|1|en}} || {{Citation needed |date=April 2022}}
|-
| France || 758{{spaces|1|en}} || {{Sfn | Hackett | 2010 | p = 368}}
|}

Artillery is used in a variety of roles depending on its type and caliber. The general role of artillery is to provide ''fire support''—"the application of fire, coordinated with the manoeuvre of forces to destroy, ''neutralize'' or ''suppress'' the enemy".  This NATO definition makes artillery a supporting arm although not all NATO armies agree with this logic. The ''italicised'' terms are NATO's.<ref>{{Citation | id = AAP-6(2006) | publisher = NATO | title = Glossary of Terms and Definitions}}.</ref>

Unlike rockets, guns (or howitzers as some armies still call them) and mortars are suitable for delivering ''close supporting fire''. However, they are all suitable for providing ''deep supporting fire'' although the limited range of many mortars tends to exclude them from the role. Their control arrangements and limited range also mean that mortars are most suited to ''direct supporting fire''. Guns are used either for this or ''general supporting fire'' while rockets are mostly used for the latter. However, lighter rockets may be used for direct fire support. These rules of thumb apply to NATO armies.

Modern [[Mortar (weapon)|mortars]], because of their lighter weight and simpler, more transportable design, are usually an integral part of [[infantry]] and, in some armies, [[Armoured fighting vehicle|armour]] units. This means they generally do not have to ''concentrate'' their fire so their shorter range is not a disadvantage. Some armies also consider infantry operated mortars to be more responsive than artillery, but this is a function of the control arrangements and not the case in all armies. However, mortars have always been used by artillery units and remain with them in many armies, including a few in NATO.

In NATO armies artillery is usually assigned a tactical mission that establishes its relationship and responsibilities to the formation or units it is assigned to. It seems that not all NATO nations use the terms and outside NATO others are probably used. The standard terms are: ''direct support'', ''general support'', ''general support reinforcing'' and ''reinforcing''. These tactical missions are in the context of the command authority: ''operational command'', ''operational control'', ''tactical command'' or ''tactical control''.

In NATO direct support generally means that the directly supporting artillery unit provides observers and liaison to the manoeuvre troops being supported, typically an artillery battalion or equivalent is assigned to a brigade and its batteries to the brigade's battalions. However, some armies achieve this by placing the assigned artillery units under command of the directly supported formation. Nevertheless, the batteries' fire can be ''concentrated'' onto a single target, as can the fire of units in range and with the other tactical missions.

===Application of fire===
[[File:155fire.jpg|right|thumb|A 155&nbsp;mm artillery shell fired by a United States [[11th Marine Regiment]] [[M198 howitzer|M-198]] [[howitzer]]]]
There are several dimensions to this subject. The first is the notion that fire may be against an ''opportunity'' target or may be ''arranged''. If it is the latter it may be either ''on-call'' or ''scheduled''. Arranged targets may be part of a ''fire plan''. Fire may be either ''observed'' or ''unobserved'', if the former it may be ''adjusted'', if the latter then it has to be ''[[predicted fire|predicted]]''. Observation of adjusted fire may be directly by a forward observer or indirectly via some other ''target acquisition'' system.

NATO also recognises several different types of fire support for tactical purposes:
* ''[[Counterbattery fire]]'': delivered for the purpose of destroying or ''neutralizing'' the enemy's fire support system.
* ''Counterpreparation fire'': intensive prearranged fire delivered when the imminence of the enemy attack is discovered.
* ''Covering fire'': used to protect troops when they are within range of enemy small arms.
* ''Defensive fire'': delivered by supporting units to assist and protect a unit engaged in a defensive action.
* ''Final Protective Fire'': an immediately available prearranged barrier of fire designed to impede enemy movement across defensive lines or areas.
* ''[[Harassing fire]]'': a random number of shells are fired at random intervals, without any pattern to it that the enemy can predict. This process is designed to hinder enemy forces' movement, and, by the constantly imposed stress, threat of losses and inability of enemy forces to relax or sleep, lowers their morale.
* ''Interdiction fire'': placed on an area or point to prevent the enemy from using the area or point.
* ''Preparation fire'': delivered before an attack to weaken the enemy position.

These purposes have existed for most of the 20th century, although their definitions have evolved and will continue to do so, lack of ''suppression'' in ''counterbattery'' is an omission. Broadly they can be defined as either:
* ''Deep supporting fire'': directed at objectives not in the immediate vicinity of own force, for neutralizing or destroying enemy reserves and weapons, and interfering with enemy command, supply, communications and observation; or
* ''Close supporting fire'': placed on enemy troops, weapons or positions which, because of their proximity present the most immediate and serious threat to the supported unit.
[[File:Gun5a.jpg|thumb|[[United States Marine Corps|USMC]] [[M198 howitzer|M-198]] firing outside of [[Fallujah]], Iraq in 2004]]
Two other NATO terms also need definition:
* ''Neutralization fire'': delivered to render a target temporarily ineffective or unusable; and
* ''Suppression fire'': that degrades the performance of a target below the level needed to fulfill its mission. Suppression is usually only effective for the duration of the fire.

The tactical purposes also include various "mission verbs", a rapidly expanding subject with the modern concept of "effects based operations".

''Targeting'' is the process of selecting target and matching the appropriate response to them taking account of operational requirements and capabilities. It requires consideration of the type of fire support required and the extent of coordination with the supported arm. It involves decisions about:
* what effects are required, for example, ''neutralization'' or ''suppression'';
* the proximity of and risks to own troops or non-combatants;
* what types of munitions, including their fuzing, are to be used and in what quantities;
* when the targets should be attacked and possibly for how long;
* what methods should be used, for example, ''converged'' or ''distributed'', whether adjustment is permissible or surprise essential, the need for special procedures such as precision or danger close
* how many fire units are needed and which ones they should be from those that are available (in range, with the required munitions type and quantity, not allotted to another target, have the most suitable line of fire if there is a risk to own troops or non-combatants);

The ''targeting'' process is the key aspect of tactical fire control. Depending on the circumstances and national procedures it may all be undertaken in one place or may be distributed. In armies practicing control from the front, most of the process may be undertaken by a forward observer or other target acquirer. This is particularly the case for a smaller target requiring only a few fire units. The extent to which the process is formal or informal and makes use of computer based systems, documented norms or experience and judgement also varies widely armies and other circumstances.

Surprise may be essential or irrelevant. It depends on what effects are required and whether or not the target is likely to move or quickly improve its protective posture. During World War II UK researchers concluded that for impact fuzed munitions the relative risk were as follows:{{citation needed|date=June 2019}}
* men standing – 1
* men lying – 1/3
* men firing from trenches – 1/15–1/50
* men crouching in trenches – 1/25–1/100
Airburst munitions significantly increase the relative risk for lying men, etc. Historically most casualties occur in the first 10–15 seconds of fire, i.e. the time needed to react and improve protective posture, however, this is less relevant if airburst is used.

There are several ways of making best use of this brief window of maximum vulnerability:
* ordering the guns to fire together, either by executive order or by a "fire at" time. The disadvantage is that if the fire is ''concentrated'' from many dispersed ''fire units'' then there will be different times of flight and the first rounds will be spread in time. To some extent a large concentration offsets the problem because it may mean that only one round is required from each gun and most of these could arrive in the 15 second window.
* burst fire, a rate of fire to deliver three rounds from each gun within 10 or 15 seconds, this reduces the number of guns and hence fire units needed, which means they may be less dispersed and have less variation in their times of flight. Smaller caliber guns, such as 105&nbsp;mm, have always been able to deliver three rounds in 15 seconds, larger calibers firing fixed rounds could also do it but it was not until the 1970s that a multi-charge 155&nbsp;mm howitzer, [[FH-70]] first gained the capability.
* multiple round simultaneous impact (MRSI), where a single weapon or multiple individual weapons fire multiple rounds at differing trajectories so that all rounds arrive on target at the same time.
* ''time on target'', fire units fire at the time less their time of flight, this works well with prearranged scheduled fire but is less satisfactory for opportunity targets because it means delaying the delivery of fire by selecting a 'safe' time that all or most fire units can achieve. It can be used with both the previous two methods.

===Counter-battery fire===
{{Main|Counter-battery fire}}
Modern counter-battery fire developed in [[World War I]], with the objective of defeating the enemy's artillery. Typically such fire was used to suppress enemy batteries when they were or were about to interfere with the activities of friendly forces (such as to prevent enemy defensive artillery fire against an impending attack) or to systematically destroy enemy guns. In World War I the latter required air observation. The first indirect counter-battery fire was in May 1900 by an observer in a balloon.{{Citation needed|date=January 2022}}

Enemy artillery can be detected in two ways, either by direct observation of the guns from the air or by ground observers (including specialist reconnaissance), or from their firing signatures. This includes radars tracking the shells in flight to determine their place of origin, sound ranging detecting guns firing and resecting their position from pairs of microphones or cross-observation of gun flashes using observation by human observers or opto-electronic devices, although the widespread adoption of 'flashless' propellant limited the effectiveness of the latter.

Once hostile batteries have been detected they may be engaged immediately by friendly artillery or later at an optimum time, depending on the tactical situation and the counter-battery policy. Air strike is another option. In some situations the task is to locate all active enemy batteries for attack using a counter-battery fire at the appropriate moment in accordance with a plan developed by artillery intelligence staff. In other situations counter-battery fire may occur whenever a battery is located with sufficient accuracy.

Modern counter-battery target acquisition uses unmanned aircraft, [[counter-battery radar]], ground reconnaissance and sound-ranging. Counter-battery fire may be adjusted by some of the systems, for example the operator of an unmanned aircraft can 'follow' a battery if it moves. Defensive measures by batteries include frequently changing position or constructing defensive earthworks, the tunnels used by North Korea being an extreme example. Counter-measures include air defence against aircraft and attacking counter-battery radars physically and electronically.

[[File:PzH2000Munition.jpg|thumb|upright=0.9|right|Modern artillery ammunition. Caliber 155&nbsp;mm as used by the [[PzH 2000]]]]

===Field artillery team===
{{Main|Field artillery team}}
'Field Artillery Team' is a US term and the following description and terminology applies to the US, other armies are broadly similar but differ in significant details. Modern field artillery (post–World War I) has three distinct parts: the [[forward observer|Forward Observer (FO)]], the [[fire direction center|Fire Direction Center (FDC)]]  and the actual guns themselves. The forward observer observes the target using tools such as [[binoculars]], [[laser rangefinder]]s, designators and call back fire missions on his radio, or relays the data through a portable computer via an encrypted digital radio connection protected from jamming by computerized frequency hopping. A lesser known part of the team is the FAS or Field Artillery Survey team which sets up the "Gun Line" for the cannons. Today most artillery battalions use an "Aiming Circle" which allows for faster setup and more mobility. FAS teams are still used for checks and balances purposes and if a gun battery has issues with the "Aiming Circle" a FAS team will do it for them.

The FO can communicate directly with the battery FDC, of which there is one per each [[Artillery battery|battery]] of 4–8 guns. Otherwise the several FOs communicate with a higher FDC such as at a Battalion level, and the higher FDC prioritizes the targets and allocates fires to individual batteries as needed to engage the targets that are spotted by the FOs or to perform preplanned fires.

The Battery FDC computes firing data—ammunition to be used, powder charge, fuse settings, the direction to the target, and the quadrant elevation to be fired at to reach the target, what gun will fire any rounds needed for adjusting on the target, and the number of rounds to be fired on the target by each gun once the target has been accurately located—to the guns. Traditionally this data is relayed via radio or wire communications as a warning order to the guns, followed by orders specifying the type of ammunition and fuse setting, direction, and the elevation needed to reach the target, and the method of adjustment or orders for fire for effect (FFE). However, in more advanced artillery units, this data is relayed through a digital radio link.

Other parts of the field artillery team include meteorological analysis to determine the temperature, humidity and pressure of the air and wind direction and speed at different altitudes. Also radar is used both for determining the location of enemy artillery and mortar batteries and to determine the precise actual strike points of rounds fired by battery and comparing that location with what was expected to compute a registration allowing future rounds to be fired with much greater accuracy.

=== Time on target ===
{{main|Time on target}}
A technique called time on target (TOT) was developed by the British Army in North Africa at the end of 1941 and early 1942 particularly for counter-battery fire and other concentrations, it proved very popular. It relied on BBC time signals to enable officers to synchronize their watches to the second because this avoided the need to use military radio networks and the possibility of losing surprise, and the need for field telephone networks in the desert.<ref>The Development of Artillery Tactics and Equipment, Brigadier AL Pemberton, 1950, The War Office, pg 129</ref> With this technique the time of flight from each fire unit (battery or troop) to the target is taken from the range or firing tables, or the computer and each engaging fire unit subtracts its time of flight from the TOT to determine the time to fire. An executive order to fire is given to all guns in the fire unit at the correct moment to fire. When each fire unit fires their rounds at their individual firing time all the opening rounds will reach the target area almost simultaneously. This is especially effective when combined with techniques that allow fires for effect to be made without preliminary adjusting fires.

===Multiple round simultaneous impact===
[[File:MRSI-trajectories.svg|thumb|Illustration of different trajectories used in MRSI: For any muzzle velocity there is a steeper (> 45°, solid line) and a lower (<45°, dashed line) trajectory. On these different trajectories, the shells have different flight times.]]
{{MRSI_animation_SMIL.svg}}
Multiple round simultaneous impact (MRSI) is a modern version of the earlier [[time on target]] concept. MRSI is when a single gun fires multiple shells so all arrive at the same target simultaneously. This is possible because there is more than one trajectory for a round to fly to any given target. Typically one is below 45 degrees from horizontal and the other is above it, and by using different sized propellant charges with each shell, it is possible to utilize more than two trajectories. Because the higher trajectories cause the shells to arc higher into the air, they take longer to reach the target. If shells are fired on higher trajectories for initial volleys (starting with the shell with the most propellant and working down) and later volleys are fired on the lower trajectories, with the correct timing the shells will all arrive at the same target simultaneously. This is useful because many more shells can land on the target with no warning. With traditional methods of firing, the target area may have time (however long it takes to reload and re-fire the guns) to take cover between volleys. However, guns capable of burst fire can deliver multiple rounds in a few seconds if they use the same firing data for each, and if guns in more than one location are firing on one target they can use Time on Target procedures so that all their shells arrive at the same time and target.

MRSI has a few prerequisites. The first is guns with a high rate of fire. The second is the ability to use different sized propellant charges. Third is a fire control computer that has the ability to compute MRSI volleys and the  capability to produce firing data, sent to each gun, and then presented to the gun commander in the correct order.<ref>{{cite journal |last1=Hu |first1=Xin Jun |last2=Wang |first2=Hang Yu |title= Effectiveness Calculation of Multiple Rounds Simultaneous Impact Shooting Method Based on Monte Carlo Method |journal=Applied Mechanics and Materials |date=September 2013 |volume=397–400 |pages= 2459–63 |doi=10.4028/www.scientific.net/AMM.397-400.2459|s2cid=111026161 }}</ref><ref>{{cite web |title= Multiple Rounds Simultaneous Impact, adjustable simulation |url=https://www.geogebra.org/m/r82YhC8d |website= GeoGebra | date= 30 May 2017}}</ref>  The number of rounds that can be delivered in MRSI depends primarily on the range to the target and the rate of fire. To allow the most shells to reach the target, the target has to be in range of the lowest propellant charge.

Examples of guns with a rate of fire that makes them suitable for MRSI includes UK's [[AS-90]], South Africa's [[Denel G6]]-52 (which can land six rounds simultaneously at targets at least {{convert |25|km|0|abbr= on}} away), Germany's [[Panzerhaubitze 2000]]<ref>{{cite web |title=Hungary purchases a brutal military beast that can eliminate targets from over 60 kilometres |url= https://dailynewshungary.com/hungary-purchases-a-brutal-military-beast-that-can-eliminate-targets-from-over-60-kilometres/ |website= Daily News Hungary |date= 9 January 2019}}</ref> (which can land five rounds simultaneously at targets at least {{convert|17|km|0|abbr=on}} away), Slovakia's [[155mm SpGH ZUZANA|155 mm SpGH ZUZANA 2]],<ref>{{Cite web |title=Kotadef article on 155mm SpGH Zuzana |url=https://kotadef.sk/projekty/zuzana/?lang=en |access-date=2025-01-02}}</ref> and [[K9 Thunder]].<ref>{{Cite web |title= Finnish Army report on K9 Thunder |url=https://maavoimat.fi/en/self-propelled-howitzer-k9-thunder |access-date=2025-01-02}}</ref>

The [[Archer Artillery System|Archer project]] (developed by BAE-Systems Bofors in Sweden) is a 155&nbsp;mm howitzer on a wheeled chassis which is claimed to be able to deliver up to six shells on target simultaneously from the same gun. The 120&nbsp;mm twin barrel [[AMOS]] mortar system, joint developed by [[BAE Systems Hägglunds|Hägglunds]] (Sweden) and [[Patria (company)|Patria]] (Finland),<ref>{{Cite web | place = [[Finland|FI]] | url= http://www.patriahagglunds.fi/ |title= Patria hagglunds |access-date=April 4, 2010 |archive-url= https://web.archive.org/web/20100404172145/http://www.patriahagglunds.fi/ |archive-date=April 4, 2010 |url-status= dead |df=mdy-all}}</ref> is capable of 7 + 7 shells MRSI. The United States [[XM2001 Crusader|Crusader]] program (now cancelled) was slated to have MRSI capability. It is unclear how many fire control computers have the necessary capabilities.

Two-round MRSI firings were a popular artillery demonstration in the 1960s, where well trained detachments could show off their skills for spectators.

===Air burst===
{{Main|Air burst}}
The destructiveness of artillery bombardments can be enhanced when some or all of the shells are set for airburst, meaning that they explode in the air above the target instead of upon impact. This can be accomplished either through time [[Fuze (explosives)|fuzes]] or [[proximity fuze]]s. Time fuzes use a precise timer to detonate the shell after a preset delay. This technique is tricky and slight variations in the functioning of the fuze can cause it to explode too high and be ineffective, or to strike the ground instead of exploding above it. Since December 1944 ([[Battle of the Bulge]]), proximity fuzed artillery shells have been available that take the guesswork out of this process. These employ a miniature, low powered [[radar]] transmitter in the fuze to detect the ground and explode them at a predetermined height above it.  The return of the weak radar signal completes an electrical circuit in the fuze which explodes the shell.  The proximity fuze itself was developed by the British to increase the effectiveness of [[anti-aircraft warfare]].

This is a very effective tactic against infantry and light vehicles, because it scatters the [[fragmentation (weaponry)|fragmentation]] of the shell over a larger area and prevents it from being blocked by terrain or entrenchments that do not include some form of robust overhead cover.  Combined with TOT or MRSI tactics that give no warning of the incoming rounds, these rounds are especially devastating because many enemy soldiers are likely to be caught in the open; even more so if the attack is launched against an assembly area or troops moving in the open rather than a unit in an entrenched tactical position.