![BOLT117LGB](https://upload.wikimedia.org/wikipedia/commons/2/20/BOLT117LGB.jpg)
A guided bomb (also known as a smart bomb, guided bomb unit, or GBU) is a
precision-guided munition designed to achieve a smaller
circular error probable (CEP).
The creation of precision-guided munitions resulted in the retroactive renaming of older bombs as
unguided bomb
An unguided bomb, also known as a free-fall bomb, gravity bomb, dumb bomb, or iron bomb, is a conventional or nuclear aircraft-delivered bomb that does not contain a guidance system and hence simply follows a ballistic trajectory. This describe ...
s or "dumb bombs".
Guidance
Guided bombs carry a guidance system which is usually monitored and controlled from an external device. A guided bomb of a given weight must carry fewer explosives to accommodate the guidance mechanisms.
Radio
The Germans were first to introduce Precision Guided Munitions (PGMs) in combat, using the 1,400-kg (3,100 lb)
MCLOS
Manual command to line of sight (MCLOS) is a method for guiding guided missiles.
With an MCLOS missile, the operator must track the missile and the target simultaneously and guide the missile to the target. Typically the missile is steered with a ...
-guidance
Fritz X
Fritz X was the most common name for a German guided anti-ship glide bomb used during World War II. ''Fritz X'' was the world's first precision guided weapon deployed in combat and the first to sink a ship in combat. ''Fritz X'' was a nickname us ...
to successfully attack the Italian
battleship ''Roma'' in September 1943. The closest
Allied equivalents were the 1,000-lb (454 kg)
AZON (AZimuth ONly), used in both Europe and the
CBI Theater, and the
US Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...
's
Bat
Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most ...
, primarily used in the Pacific Theater of World War II which used autonomous, on-board radar guidance. In addition, the U.S. tested the rocket-propelled
Gargoyle
In architecture, and specifically Gothic architecture, a gargoyle () is a carved or formed grotesque with a spout designed to convey water from a roof and away from the side of a building, thereby preventing it from running down masonry walls ...
; it never entered service. No Japanese remotely guided PGMs ever saw service in World War II.
The
United States Army Air Forces
The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...
used similar techniques with
Operation Aphrodite
Aphrodite and Anvil were the World War II code names of United States Army Air Forces and United States Navy operations to use Boeing B-17 Flying Fortress and Consolidated PB4Y bombers as precision-guided munitions against bunkers and other har ...
, but had few successes; the German
Mistel
''Mistel'' (German for " mistletoe", a parasitic plant) was the larger, unmanned component of a composite aircraft configuration developed in Germany during the later stages of World War II. The composite comprised a small piloted control airc ...
(Mistletoe) "
parasite aircraft
A parasite aircraft is a component of a composite aircraft which is carried aloft and air launched by a larger carrier aircraft or mother ship to support the primary mission of the carrier. The carrier craft may or may not be able to later reco ...
" was no more effective.
The U.S. programs restarted in the
Korean War
, date = {{Ubl, 25 June 1950 – 27 July 1953 (''de facto'')({{Age in years, months, weeks and days, month1=6, day1=25, year1=1950, month2=7, day2=27, year2=1953), 25 June 1950 – present (''de jure'')({{Age in years, months, weeks a ...
. In the 1960s, the ''
electro-optical
Electro–optics is a branch of electrical engineering, electronic engineering, materials science, and material physics involving components, electronic devices such as lasers, laser diodes, LEDs, waveguides, etc. which operate by the propag ...
bomb'' (or ''camera bomb'') was reintroduced. They were equipped with
television
Television, sometimes shortened to TV, is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertisin ...
camera
A camera is an optical instrument that can capture an image. Most cameras can capture 2D images, with some more advanced models being able to capture 3D images. At a basic level, most cameras consist of sealed boxes (the camera body), with a ...
s and flare sights, by which the bomb would be steered until the flare superimposed the target. The camera bombs transmitted a "bomb's eye view" of the target back to a controlling aircraft. An operator in this aircraft then transmitted control signals to steerable fins fitted to the bomb. Such weapons were used increasingly by the
USAF
The United States Air Force (USAF) is the Aerial warfare, air military branch, service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part ...
in the last few years of the
Vietnam War
The Vietnam War (also known by other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vietnam a ...
because the political climate was increasingly intolerant of civilian casualties, and because it was possible to strike difficult targets (such as bridges) effectively with a single mission; the
Thanh Hoa Bridge, for instance, was attacked repeatedly with gravity bombs, to no effect, only to be dropped in one mission with PGMs.
Although not as popular as the newer
JDAM
The Joint Direct Attack Munition (JDAM) is a guidance kit that converts unguided bombs, or "dumb bombs", into all-weather precision-guided munitions. JDAM-equipped bombs are guided by an integrated inertial guidance system coupled to a Global Po ...
and
JSOW
The AGM-154 Joint Standoff Weapon (JSOW) is a glide bomb that resulted from a joint venture between the United States Navy and Air Force to deploy a standardized medium range precision guided weapon, especially for engagement of defended targets ...
weapons, or even the older
laser-guided bomb
A laser-guided bomb (LGB) is a guided bomb that uses semi-active laser guidance to strike a designated target with greater accuracy than an unguided bomb. First developed by the United States during the Vietnam War, laser-guided bombs quickly p ...
systems, weapons like the
AGM-62 Walleye
The AGM-62 Walleye is a television-guided glide bomb which was produced by Martin Marietta and used by the United States Armed Forces from the 1960s-1990s. Most had a 250 lb (113 kg) high-explosive warhead; some had a nuclear warhea ...
TV-guided bomb are still being used, in conjunction with the
AAW-144 Data Link Pod, on
US Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...
F/A-18 Hornets.
Infrared
In World War II, the U.S.
National Defense Research Committee
The National Defense Research Committee (NDRC) was an organization created "to coordinate, supervise, and conduct scientific research on the problems underlying the development, production, and use of mechanisms and devices of warfare" in the Un ...
developed the
VB-6 Felix
The VB-6 Felix was a precision-guided munition developed by the United States during World War II. It used an infrared seeker to attack targets like blast furnaces or the metal roofs of large factories. The war ended before it could be used ope ...
, which used infrared to home on ships. While it entered production in 1945, it was never employed operationally.
Laser
![GBU-10 shortly before it impacts a small boat during a training exercise](https://upload.wikimedia.org/wikipedia/commons/c/c8/GBU-10_shortly_before_it_impacts_a_small_boat_during_a_training_exercise.jpg)
In 1962, the US Army began research into
laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fi ...
guidance systems and by 1967 the USAF had conducted a competitive evaluation leading to full development of the world's first
laser-guided bomb
A laser-guided bomb (LGB) is a guided bomb that uses semi-active laser guidance to strike a designated target with greater accuracy than an unguided bomb. First developed by the United States during the Vietnam War, laser-guided bombs quickly p ...
, the
BOLT-117
The Texas Instruments BOLT-117 (BOmb, Laser Terminal-117), retrospectively redesignated as the GBU-1/B (Guided Bomb Unit) was the world's first laser-guided bomb (LGB). It consisted of a standard M117 bomb case with a KMU-342 laser guidance and ...
, in 1968. All such bombs work in much the same way, relying on the target being illuminated, or "painted," by a laser target designator on the ground or on an aircraft. They have the significant disadvantage of not being usable in poor weather where the target illumination cannot be seen, or where it is not possible to get a target designator near the target. The laser designator sends its beam in a series of
encrypted
In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Ideally, only authorized parties can deci ...
pulses so the bomb cannot be confused by an ordinary laser, and also so multiple designators can operate in reasonable proximity.
Laser-guided weapons did not become commonplace until the advent of the microchip. They made their practical debut in Vietnam, where on 13 May 1972 when they were used in the second successful attack on the Thanh Hoa Bridge ("Dragon's Jaw"). This structure had previously been the target of 800 American sorties (using unguided weapons) and was partially destroyed in each of two successful attacks, the other being on 27 April 1972 using
Walleye
The walleye (''Sander vitreus'', synonym ''Stizostedion vitreum''), also called the yellow pike or yellow pickerel, is a freshwater perciform fish native to most of Canada and to the Northern United States. It is a North American close relat ...
s. That first mission also had laser-guided weapons, but bad weather prevented their use. They were used, though not on a large scale, by the British forces during the 1982
Falklands War. The first large-scale use of smart weapons came in 1991 during Operation
Desert Storm
The Gulf War was a 1990–1991 armed campaign waged by a 35-country military coalition in response to the Iraqi invasion of Kuwait. Spearheaded by the United States, the coalition's efforts against Iraq were carried out in two key phases: ...
when they were used by coalition forces against
Iraq
Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to the north, Iran to the east, the Persian Gulf and K ...
. Even so, most of the air-dropped ordnance used in that war was "dumb," although the percentages are biased by the large use of various (unguided)
cluster bombs. Laser-guided weapons were used in large numbers during the 1999
Kosovo War
The Kosovo War was an armed conflict in Kosovo that started 28 February 1998 and lasted until 11 June 1999. It was fought by the forces of the Federal Republic of Yugoslavia (i.e. Serbia and Montenegro), which controlled Kosovo before the wa ...
, but their effectiveness was often reduced by the poor weather conditions prevalent in the southern Balkans.
There are two basic families of laser-guided bombs in American (and American-sphere) service: the
Paveway
Paveway is a series of laser-guided bombs (LGBs).
''Pave'' or PAVE is sometimes used as an acronym for ''precision avionics vectoring equipment''; literally, electronics for controlling the speed and direction of aircraft. Laser guidance is ...
II and the Paveway III. The Paveway III guidance system is more aerodynamically efficient and so has a longer range, however it is more expensive. Paveway II 500-pound LGBs (such as GBU-12) are a cheaper lightweight PGM suitable for use against vehicles and other small targets, while a Paveway III 2000-pound penetrator (such as GBU-24) is a more expensive weapon suitable for use against high-value targets. GBU-12s were used to great effect in the first
Gulf War
The Gulf War was a 1990–1991 armed campaign waged by a Coalition of the Gulf War, 35-country military coalition in response to the Iraqi invasion of Kuwait. Spearheaded by the United States, the coalition's efforts against Ba'athist Iraq, ...
, dropped from
F-111F aircraft to destroy Iraqi armored vehicles in a process referred to as "tank plinking."
Satellite
![F-22 bomb](https://upload.wikimedia.org/wikipedia/commons/b/b7/F-22_bomb.jpg)
Lessons learned during the first Gulf War showed the value of precision munitions, yet they also highlighted the difficulties in employing them—specifically when visibility of the ground or target from the air was degraded. The problem of poor visibility does not affect satellite-guided weapons such as
Joint Direct Attack Munition (JDAM) and
Joint Stand-Off Weapon
The AGM-154 Joint Standoff Weapon (JSOW) is a glide bomb that resulted from a joint venture between the United States Navy and Air Force to deploy a standardized medium range precision guided weapon, especially for engagement of defended targets ...
(JSOW), which make use of the United States'
GPS
The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite sy ...
system for guidance. This weapon can be employed in all weather conditions, without any need for ground support. Because it is possible to
jam
Jam is a type of fruit preserve.
Jam or Jammed may also refer to:
Other common meanings
* A firearm malfunction
* Block signals
** Radio jamming
** Radar jamming and deception
** Mobile phone jammer
** Echolocation jamming
Arts and ente ...
GPS, the guidance package reverts to
inertial navigation
An inertial navigation system (INS) is a navigation device that uses motion sensors ( accelerometers), rotation sensors ( gyroscopes) and a computer to continuously calculate by dead reckoning the position, the orientation, and the velocity ...
in the event of GPS signal loss. Inertial navigation is significantly less accurate; the JDAM achieves a published circular error probable (CEP) of 13 m under GPS guidance, but typically only 30 m under inertial guidance (with free fall times of 100 seconds or less).
![BGT Hosbo](https://upload.wikimedia.org/wikipedia/commons/3/35/BGT_Hosbo.jpg)
The precision of these weapons is dependent both on the precision of the measurement system used for location determination and the precision in setting the coordinates of the target. The latter critically depends on intelligence information, not all of which is accurate. According to a CIA report, the accidental
bombing of the Chinese embassy in Belgrade during
Operation Allied Force
The North Atlantic Treaty Organization (NATO) carried out an aerial bombing campaign against the Federal Republic of Yugoslavia during the Kosovo War. The air strikes lasted from 24 March 1999 to 10 June 1999. The bombings continued until an a ...
by NATO aircraft was attributed to faulty target information. However, if the targeting information ''is'' accurate, satellite-guided weapons are significantly more likely to achieve a successful strike in any given weather conditions than any other type of precision-guided munition.
Other military satellite guidance systems include: Russian
GLONASS
GLONASS (russian: ГЛОНАСС, label=none, ; rus, links=no, Глобальная навигационная спутниковая система, r=Global'naya Navigatsionnaya Sputnikovaya Sistema, t=Global Navigation Satellite System) is ...
, European
Galileo (satellite navigation)
Galileo is a satellite navigation, global navigation satellite system (GNSS) that went live in 2016, created by the European Union through the European Space Agency (ESA), operated by the European Union Agency for the Space Programme (EUSPA) ...
, Chinese
BeiDou Navigation Satellite System
The BeiDou Navigation Satellite System (BDS; ) is a Chinese satellite navigation system. It consists of two separate satellite constellations. The first BeiDou system, officially called the BeiDou Satellite Navigation Experimental System and ...
, regional
Indian Regional Navigation Satellite System
The Indian Regional Navigation Satellite System (IRNSS), with an operational name of NavIC (acronym for 'Navigation with Indian Constellation; also, 'sailor' or 'navigator' in Indian languages), is an autonomous regional satellite navigation s ...
, Japanese regional
Quasi-Zenith Satellite System
The Quasi-Zenith Satellite System (QZSS), also known as , is a four-satellite regional time transfer system and a satellite-based augmentation system developed by the Japanese government to enhance the United States-operated Global Position ...
.
History
The guided bomb had its origins in
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
. Its usage increased after the success of the weapon in the Gulf War.
World War II
In World War II, the aforementioned Fritz X and
Henschel Hs 293 guided ordnance designs were used in combat by Nazi Germany against ships, as the
USAAF
The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...
would do with the Azon in hitting bridges and other hard-to-hit targets in both Western Europe and Burma. Later, U.S.
National Defense Research Committee
The National Defense Research Committee (NDRC) was an organization created "to coordinate, supervise, and conduct scientific research on the problems underlying the development, production, and use of mechanisms and devices of warfare" in the Un ...
developed the
VB-6 Felix
The VB-6 Felix was a precision-guided munition developed by the United States during World War II. It used an infrared seeker to attack targets like blast furnaces or the metal roofs of large factories. The war ended before it could be used ope ...
, which used infrared to home on ships. While it entered production in 1945, it was never employed operationally.
Korean War
The US briefly deployed the
ASM-A-1 Tarzon
The ASM-A-1 Tarzon, also known as VB-13, was a guided bomb developed by the United States Army Air Forces during the late 1940s. Mating the guidance system of the earlier Razon radio-controlled weapon with a British Tallboy bomb, the ASM-A-1 sa ...
(or VB-13 Tarson) bomb (a
Tallboy fitted with radio guidance) during the
Korean War
, date = {{Ubl, 25 June 1950 – 27 July 1953 (''de facto'')({{Age in years, months, weeks and days, month1=6, day1=25, year1=1950, month2=7, day2=27, year2=1953), 25 June 1950 – present (''de jure'')({{Age in years, months, weeks a ...
, dropping them from
Boeing B-29 Superfortresses.
Vietnam War
In 1962, the US Army began research into
laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fi ...
guidance systems and by 1967 the USAF had conducted a competitive evaluation leading to full development of the world's first
laser-guided bomb
A laser-guided bomb (LGB) is a guided bomb that uses semi-active laser guidance to strike a designated target with greater accuracy than an unguided bomb. First developed by the United States during the Vietnam War, laser-guided bombs quickly p ...
, the
BOLT-117
The Texas Instruments BOLT-117 (BOmb, Laser Terminal-117), retrospectively redesignated as the GBU-1/B (Guided Bomb Unit) was the world's first laser-guided bomb (LGB). It consisted of a standard M117 bomb case with a KMU-342 laser guidance and ...
, in 1968.
Gulf War
GBU-12 Paveway II
The GBU-12 Paveway II is an American aerial laser-guided bomb, based on the Mk 82 500-pound (227 kg) general-purpose bomb, but with the addition of a nose-mounted laser seeker and fins for guidance. A member of the Paveway series of weapons, ...
s were used to great effect in the first
Gulf War
The Gulf War was a 1990–1991 armed campaign waged by a Coalition of the Gulf War, 35-country military coalition in response to the Iraqi invasion of Kuwait. Spearheaded by the United States, the coalition's efforts against Ba'athist Iraq, ...
, dropped from
F-111F aircraft to destroy Iraqi armored vehicles in a process referred to as "
tank plinking".
War on Terror
Lessons learned during the first Gulf War showed the value of guided bombs, with precision-guided munitions accounting for 70% of munitions expended during
Operation Enduring Freedom.
Advanced guidance concepts
Responding to after-action reports from pilots who employed laser and/or satellite guided weapons,
Boeing
The Boeing Company () is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, telecommunications equipment, and missiles worldwide. The company also provides leasing and p ...
has developed a Laser JDAM (LJDAM) to provide both types of guidance in a single kit. Based on the existing
JDAM
The Joint Direct Attack Munition (JDAM) is a guidance kit that converts unguided bombs, or "dumb bombs", into all-weather precision-guided munitions. JDAM-equipped bombs are guided by an integrated inertial guidance system coupled to a Global Po ...
configurations, a laser guidance package is added to a GPS/INS guided weapon to increase the overall accuracy of the weapons. Raytheon has developed the Enhanced Paveway family, which adds GPS/INS guidance to their Paveway family of laser-guidance packages.
Raytheon Enhanced Paveway
These "hybrid" laser and GPS guided weapons permit the carriage of fewer weapons types, while retaining mission flexibility, because these weapons can be employed equally against moving and fixed targets, or targets of opportunity. For instance, a typical weapons load on an F-16 flying in the Iraq War
{{Infobox military conflict
, conflict = Iraq War {{Nobold, {{lang, ar, حرب العراق (Arabic) {{Nobold, {{lang, ku, شەڕی عێراق ( Kurdish)
, partof = the Iraq conflict and the War on terror
, image ...
included a single 2,000-lb JDAM and two 1,000-lb LGBs. With LJDAM, and the new Small Diameter Bomb
The GBU-39/B Small Diameter Bomb (SDB) is a precision-guided glide bomb that is intended to provide aircraft with the ability to carry a higher number of more accurate bombs. Most US Air Force aircraft will be able to carry (using the BRU-61/A ...
, these same aircraft can carry more bombs if necessary, and have the option of satellite or laser guidance for each weapon release.
See also
* XM1156 Precision Guidance Kit
* M982 Excalibur
The M982 Excalibur (previously XM982) is a 155 mm extended-range guided artillery shell developed in a collaborative effort between the U.S. Army Research Laboratory (ARL) and the United States Army Armament Research, Development and Engineerin ...
* XM395 Precision Guided Mortar Munition
The XM395 Precision Guided Mortar Munition (PGMM) is a 120 mm guided mortar round developed by Alliant Techsystems.
Design
Based on Orbital ATK's Precision Guidance Kit for 155 mm artillery projectiles, XM395 combines GPS guidance and d ...
* M712 Copperhead
The M712 Copperhead is a 155 mm caliber cannon-launched guided projectile. It is
a fin-stabilized, terminally laser guided, explosive shell intended to engage hard point targets such as tanks, self-propelled howitzers or other high-value targe ...
*
* Strix mortar round
* Cruise missile
* Wire-guided missile
A wire-guided missile is a missile that is guided by signals sent to it via thin wires connected between the missile and its guidance mechanism, which is located somewhere near the launch site. As the missile flies, the wires are reeled out behi ...
* Glide bomb
A glide bomb or stand-off bomb is a standoff weapon with flight control surfaces to give it a flatter, gliding flight path than that of a conventional bomb without such surfaces. This allows it to be released at a distance from the target r ...
* Precision-guided munition
* Guidance system
* Missile
In military terminology, a missile is a guided airborne ranged weapon capable of self-propelled flight usually by a jet engine or rocket motor. Missiles are thus also called guided missiles or guided rockets (when a previously unguided rocke ...
* Missile guidance
Missile guidance refers to a variety of methods of guiding a missile or a guided bomb to its intended target. The missile's target accuracy is a critical factor for its effectiveness. Guidance systems improve missile accuracy by improving its P ...
* Terminal guidance In the field of weaponry, terminal guidance refers to any guidance system that is primarily or solely active during the "terminal phase", just before the weapon impacts its target. The term is generally used in reference to missile guidance system ...
* Proximity sensor
A proximity sensor is a sensor able to detect the presence of nearby objects without any physical contact.
A proximity sensor often emits an electromagnetic field or a beam of electromagnetic radiation (infrared, for instance), and looks for ...
* Artillery fuze
An artillery fuze or fuse is the type of munition fuze used with artillery munitions, typically projectiles fired by guns (field, anti-aircraft, coast and naval), howitzers and mortars. A fuze is a device that initiates an explosive function in a ...
* Magnetic proximity fuze A magnetic proximity fuse was patented by P.J. Eliomarkakis, (United States Patent US2434551 of January 13, 1948) although similar devices had been in service for nearly a decade. It is a type of proximity fuze that initiates a detonator in a pie ...
* Proximity fuze
Notes
External links
*"
Bomb With A Brain
'". British Pathé newsreel 52/51A, June 23, 1952.
How Smart Bombs Work
"Smart bombs" missed Iraqi targets
BBC story on the first employment of the JSOW, guidance failures were attributed to a software error that was subsequently fixed.
"Fact File: Smart Bombs - not so Smart
BBC story discussing the limitations of guided munition employment.
Ukraine develops indigenous guided airborne weapons
Article about Ukrainian guided bomb development, August 2006
World War II Glide Bombs (Part1)
World War II Glide Bombs (Part2)
Modern Glide Bombs
{{Authority control
Weapon guidance
Aerial bombs
Targeting (warfare)