The clasic artillery weapon is the gun which has been under development since the 12th century. The aim of development of the gun always was to deliver heavier shells at longer ranges accurately. The current calibre accepted universally is 155mm with a range of 40 km. Apart from range, lethality and accuracy, there are other parameters like transportation and mobility; interoperability with other systems; counter bombardment capability; digital targeting; reconnaissance, surveillance and target acquisition (RSTA) capability and cost. The key parameters out of these which are attracting attention globally are improving the accuracy and speed of delivery. Director General of Artillery Lt General P.K. Srivastava, during a recent interaction with SP’s Land Forces, commented on the shape of the future battlefield and the role of Artillery in it as follows:

Likely Shape of Future Battle Field. The future battlefield will be characterised by short and intense engagements; nonlinear battles; simultaneity of operations; increased battle field transparency; synergized and orchestrated employment of fire power resources and employment of precision and high lethality weapon systems in a hybrid warfare environment. All of this under the overall backdrop of a nuclear, biological and chemical warfare threat.

Likely Employment of Artillery. The employment of Artillery in the future in such a short and intense battles will be characterised as under:

• Due to high tempo of operations, there will be a requirement of real time surveillance and target acquisition at all stages of battle.
• Synergised and orchestrated employment of all available firepower resources to shape the battlefield and to degrade the enemy in contact and depth battle entailing employment of mortars, guns and long range vectors in conjunction with IAF to achieve decisive defeat of the enemy. Therefore Artillery should have a balance of guns (towed and self propelled), rockets and missiles. There is also a need to have a variety of ammunition and warheads to achieve desired results at the target.
• Artillery will be responsible for detecting and destruction of enemy artillery and rocket positions.
• The trend is towards precision so as to reduce logistic cost of each successful engagement.
• Dependence on artillery to achieve favourable outcomes will increase.

Technologies

Speed of delivery through automation and integration
This is achieved by automation of the RSTA. Artillery has already developed Artillery Combat Command and Control System (ACCCS-Project Sakthi) which is a major component of the Tactical Command Control Communication and Intelligence (Tac C3I) system of the Indian Army. US Artillery has the Advanced Field Artillery Tactical Data System (AFATDS) which uses “Fires XXI” computer system for both tactical and technical fire control. Due to the dual capability of Fires XXI, it has replaced the Battery Computer System (for providing technical fire solutions) and IFSAS/L-TACFIRE (for tactical fire control) systems. Rockwell Collins has developed the Joint Forward Observer Mobile digital joint fires solution (JFO Mobile) which provides digital fires solution, enables digital calls for indirect fires on artillery, mortar and range systems, is fully integrated with AFATDS, enables targeting via a digital system and final request for fire support via combat net radio when required, passes firesupport requests to C2 systems or directly to digitally enabled fire support assets and can plan comprehensive fire missions. ACCCS, AFATDS and JFO mobile provide fast reaction to fire requests, synergies all the fire power resources and integrates into the army’s command and control network. There are plans for improvements to the M777A2’s Digital Fire Control System. Select US Army artillery units will be equipped with the Joint Effects Targeting System (JETS) system which is a new handheld device that enables artillery observers and infantry soldiers to provide precision target locations and can then provide laser designation for precision ammunition. The current system is Lightweight Laser Designator Rangefinder which weighs 35 pound (about 11 kg) and considered too heavy for a single gunner to man as compared to JETS which weighs only 5.5 pounds (about 2.5 kg).

Target acquisition
Electro-optic Infrared, radar and laser systems provide the army with exceptional battlefield capabilities, both by day and night. Indigenous Weapon Locating Radar (WLR) Swathi provides fast, automatic and accurate location of enemy weapons like mortars, shells and rockets at a range of 50 km. India also has AN/TPQ-37 Firefinder which is a mobile WLR system of Thales Raytheon Systems. Its successor is TPQ-53 radar which in addition to its counter-fire and counterdrone missions, can also perform short range air defense (SHORAD) role. Laser range finders provide accurate range to the target.

Airborne Sensors
UAVs have revolutionised RSTA and target damage assessment due to their speed and reach. India has also acquired Israel Aerospace Industries’ (IAI) Searcher and Heron UAV. Brief details with some other examples are:

• Searcher. Searcher is a multi mission tactical UAV which can carry out the role of surveillance, reconnaissance, target acquisition, artillery adjustment of fire and damage assessment. Searcher has been constantly improved from MkI to MkII and MkIII. The Searcher MkIII has multiple operational configurations, SAR/GMTI (Synthetic Aperture Radar/Ground Moving Target Indicator), SIGINT and EO/IR systems. It has a maximum altitude of >23000ft (about 7010 m), endurance of 18h with a mission radius of 350km.
• AAI Corporation’s (an operating unit of Textron Systems) Shadow^®. The Shadow is designated as the RQ-7B in US and operates at brigade level. It has range of about 125 km. RQ-7B transmits imagery and telemetry data directly to the Joint Surveillance and Target Attack Radar System, Advanced Field Artillery Tactical Data System and others systems in near real time.

Precision Guidance Munition (PGM)

A PGM (also called smart weapon, smart munition, smart bomb) is a guided munition designed to precisely hit a specific target. During the Cold War period, the Soviet Union’s superior tank force presented a serious conventional threat to US and NATO forces in Europe which was partly offset by US nuclear weapons but the requirement was to provide a non-nuclear offset which started the evolution of PGMs. The experience of US Forces in Vietnam also led to the conclusion that PGMs can engage infrastructure targets like bridges and also cause less collateral damage. Other targets could be radars, integrated air defense systems and command and control centres within range. PGMs would be self guided and thus could be launched from a longer range when operating from an airborne platform thus reducing the risk to the pilot and the aircraft. PGMs used by US Forces have been successful in the Middle East and thus the adversaries have changed their tactics to include use of widely dispersed forces in urban areas thus requiring even more precision. PGMs is the area where artillery can improve radically to provide devastating, accurate and almost instant fire. As usual U.S. through Defense Advanced Research Projects Agency (DARPA) leads the field to develop PGMs to be launched from land as well as air. DARPA had been working on many technologies like lasers, electro-optical sensors, microelectronics, data processors and radars which would all become critical components of the the first PGMs.

In 1978, DARPA integrated a number of these efforts under its Assault Breaker programme which laid the technological foundation for several smart-weapon systems like the Joint Surveillance Target Attack Radar System (JSTARS), which integrated PGMs with advanced ISR systems; an Air Force air-to-ground missile with terminally guided submunitions; the long-range, quickresponse, surface-to-surface Army Tactical Missile System, which featured all-weather, day/night capability effective against mobile and other targets; and the Brilliant Antiarmor Tank (BAT) submunition, which used acoustic sensors on its wings to detect and target tanks. DARPA also miniaturized the GPS receivers in the 80s which led to advance development in inertial navigation. Other developments were the Joint Direct Attack Munitions (JDAM) GPS kits, which gave unguided or laser-guided munitions high-precision capabilities. Key to these developments were gallium arsenide chips which enabled the RF and millimeter wave circuits needed in precision weapons. The self-guided, anti-armour Javelin missile’s success was due to its the two-dimensional arrays which made missile’s seeker almost fool proof. Other developments in inertial navigation is Precision Inertial Navigation Systems (PINS), Micro inertial navigation technology (MINT) and Chip-scale atomic clock program (CSAC). PINS is an effort to address the vulnerabilities of GPS navigation like jamming, spoofing, blind spots, etc. by using ultra-cold atom interferometers to reduce the positional accuracy drift of INS by several magnitudes to achieve near-GPS accuracies. MINT aims to create high-precision navigation aiding sensors that directly measure intermediate inertial variables, such as velocity and distance, to reduce the error encountered while integrating signals from accelerometers and gyroscopes. The CSAC program is designed to create ultraminiaturized, low-power atomic time and frequency reference units that will achieve a 200X reduction in size and a 300X reduction in power consumption, with no loss in accuracy, as compared to the existing technology. A projected application is a wristwatch-size, high-security UHF communicator and jam-resistant GPS receiver, but overall CSAC could drastically improve channel selectivity and density for all military communications. All these technologies will at some stage be employed directly or indirectly for artillery PGMs.

The US Army’s Armament Research and Development Center’s Munitions Engineering Technology Centre deals with current and new generations of Precision Guidance Kit (PGK) and Excalibur, as well as the Advanced Precision Mortar Initiative (APMI—GPS guidance for 120mm mortars) and the Very Affordable Precision Projectile (VAPP) to increase ground force precision strike. Precision guidance technologies have helped converting area suppression weapons into PGMs/like Excalibur, a GPS-guided artillery projectile extending the range and accuracy of current and future 155 mm howitzers. The Army’s PGK, which replaces the fuse in the nose of conventional 155-mm artillery, similar to what the Air Force Joint Direct Attack Munition did for “dumb” bombs.PGK provides a Circular Error of Probability of 50m for all ranges, depending on the type of ammunition being fired. There are plans to develop scalable lethality from non-lethal to lethal responses which will require more precise target locating devices and smaller munitions. PGMs need reliable power supply thus is another area of development is to provide reliable and small sized batteries which have a long shelf life. The future PGM will be having variable lethality, can be redirected or terminated in flight. It should be able to operate in any environment, with or without GPS and be able to change the type of explosion to match the target.

Non-Line-of-Sight Launch System (NLOS-LS)

The NLOS-LS, previously known as Net-Fires and as the Advanced Fire Support System, was a technology demonstration programme focused on beyond line-of-sight fires for the Army’s Future Combat System. It is planned for missiles in canister to be vertically launched, with a command and control system in a box. The round in its launch canister is a complete entity. Being in a box means NLOS-LS can be mounted on a Humvee or a truck, or set up on the ground. The NLOS-LS can be utilized in the Army’s Unmanned Surface Vehicle and in the Navy’s Littoral Combat Ship. NLOS-LS has two missiles. The first is a Precision Attack Missile (PAM), which was formerly developed by Raytheon Corporation. The missile travels at high speed for minimal time to target or to reach maximum range. It has a variable thrust motor, an uncooled infrared laser seeker and a multi-mode warhead. The PAM can be utilized for both hard and soft targets. The second is a Loitering Attack Missile (LAM), which has continued to be developed by both Lockheed Martin and Raytheon. It carries a laser detection and ranging (“ladar”) seeker, a turbojet motor, and wings that extend on launch. The missile has a 70km range with a 30-minute loiter time. It is able to loiter over targets of interest, do automatic target recognition and attack targets on its own.

Magneto Hydrodynamic Explosive Munition (MAHEM) Programme

Explosively formed jets (EFJ) and fragments and self-forging penetrators (SFP) are used for precision strike against targets such as armored vehicles and reinforced structures for which chemical explosive energy is used. The MAHEM programme aims for higher efficiency by using compressed magnetic flux generator (CMFG)-driven magneto hydro-dynamically formed metal jets and SFP with significantly improved performance over EFJ.

Multi-Azimuth Defense — Fast Intercept Round Engagement System (MAD-FIRES)

This programme plans to combine the precision and maneuverability of a smart missile with the rapid-fire capability of an artillery shell. Raytheon has been contracted to develop such a device. MAD-FIRES aims to incorporate enhanced ammunition rounds able to alter their flight path in real time to stay on target, and a capacity to continuously target, track and engage multiple fast-approaching targets simultaneously and re-engage any targets that survive initial engagement.

High Explosive Guided Mortar (HEGM)

The aim of HEGM is to provide integral indirect fire mortar munition to Manoeuvre Battalion and at Special Operations levels. The XM395 will engage targets as close as 500m-6,500m threshold and 1,000 m-15000m objective.

Some examples of current PGMs

M982 Excalibur. This is a 155mm extended range guided artillery shell developed by Raytheon Missile Systems and BAE Systems AB. It is a GPS-guided munition, capable of being used for close support of within 75-150 m of friendly troops. It has a range of 40-57km and CEP of around 5-20 m.

M712 Copperhead. This can be fired from a 155mm calibre gun , is fin-stabilized, terminally laser guided, explosive shell intended to engage hard point targets such as tanks, self-propelled howitzers or other highvalue targets. It can be fired from many types of 155mm calibre artillery guns like M777, M198 etc. The projectile has a minimum range of 3 km and a maximum range of 16 km. For Copperhead to function, the target must be illuminated with a laser designator. Once the laser signal is detected, the onboard guidance system will operate the steering vanes to maneuver the projectile to the target. Copperhead operates in two modes. Ballistic mode is used with good visibility and high cloud ceiling. Glide mode is used with low visibility and low cloud ceiling.

XM395 Precision Guided Mortar Munition (PGMM). This is a 120mm guided mortar round developed by Alliant Techsystems. Based on Orbital ATK’s Precision Guidance Kit for 155mm artillery projectiles, XM395 combines GPS guidance and directional control surfaces into a package that replaces standard fuzes, transforming existing 120mm mortar bodies into PGMs. It has CEP of 5m at a range of 7000m.

M898 155mm Sense and Destroy Armour (SADARM) shell. SADARM can be fired from a normal 155mm artillery gun. SADARM shell has a nose-mounted M762/ M767 fuse set to burst at 1,000 m above the target for releasing two SADARM submunitions. The submunition is ejected from the projectile with the help of two parachutes. Each sensor with the submunitions has a milli-meter radiometer which scans an area of 150m in diameter,tracks and guides the submunition onto the target.