Ground-directed bombing (GDB) is a military tactic for

airstrike An airstrike, air strike or air raid is an offensive operation carried out by aircraft. Air strikes are delivered from aircraft such as blimps, balloons, fighters, heavy bombers, ground attack aircraft, attack helicopters and drones. The off ...

s by

ground-attack aircraft An attack aircraft, strike aircraft, or attack bomber is a tactical military aircraft that has a primary role of carrying out airstrikes with greater precision than bombers, and is prepared to encounter strong low-level air defenses while pres ...

, strategic bombers, and other equipped air vehicles under

command guidance Command guidance is a type of missile guidance in which a ground station or aircraft relay signals to a guided missile via radio control or through a wire connecting the missile to the launcher and tell the missile where to steer to intercept its ...

from aviation ground support equipment and/or ground personnel (e.g., ground observers). Often used in poor weather and at night (75% of all

Vietnam War The Vietnam War (also known by #Names, 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 Vie ...

bombings "were done with GDB"), the tactic was superseded by an airborne computer predicting unguided bomb impact from data provided by precision avionics (e.g., GPS,

GPS/INS GPS/INS is the use of GPS satellite signals to correct or calibrate a solution from an inertial navigation system (INS). The method is applicable for any GNSS/INS system. Overview GPS/INS method The GPS gives an absolute drift-free position v ...

, etc.) Equipment for radar GDB generally included a combination ground radar/computer/communication system ("Q" system) and aircraft avionics for processing radioed commands. A 21st century variant of ground-directed bombing is the radio

for armed

unmanned aerial vehicle An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without any human pilot, crew, or passengers on board. UAVs are a component of an unmanned aircraft system (UAS), which includes adding a ground-based controll ...

s to effect ground-directed release of ordnance (e.g.,

precision-guided munition A precision-guided munition (PGM, smart weapon, smart munition, smart bomb) is a guided munition intended to precisely hit a specific target, to minimize collateral damage and increase lethality against intended targets. During the First Gu ...

s for bombing such as the

AGM-114 Hellfire The AGM-114 Hellfire is an air-to-ground missile (AGM) first developed for anti-armor use, later developed for precision drone strikes against other target types, especially high-value targets. It was originally developed under the name ''Hel ...

World War II

In early 1945, ground-directed bombing was invented by Lt Col Reginald Clizbe, deputy commander of the

47th Bombardment Group 47th may refer to: Chicago Transit Authority stations * 47th station (CTA Green Line) 47th is a station on the Chicago Transit Authority's "L" system, located in the Grand Boulevard community area of Chicago, Illinois and serving the Green ...

(Light), using automatic tracking radar in Northern Italy for A-26C missions (e.g., in the

Po Valley The Po Valley, Po Plain, Plain of the Po, or Padan Plain ( it, Pianura Padana , or ''Val Padana'') is a major geographical feature of Northern Italy. It extends approximately in an east-west direction, with an area of including its Venetic ex ...

). Development was by a team that included Donald H. Falkingham (who was awarded the Air Meda

that modified radar plotting to transmit control commands to the pilot direction indicator (bomb release was eventually automated from the ground radar). NOTE: "bombing by radar-control" is identified in a "19 February 1945" listing of the Combat Chronolog

/ref> Similar to the ground training configuration in the US for bombardiers with the

Norden bombsight The Norden Mk. XV, known as the Norden M series in U.S. Army service, is a bombsight that was used by the United States Army Air Forces (USAAF) and the United States Navy during World War II, and the United States Air Force in the Korean ...

, in a tent near the SCR-284 radar a bombsight was automatically positioned over a large map by the plotting signals converted from the radar track's spherical coordinates from the SCR-284 ranging and antenna pointing circuits. The guidance signals output from the moving bombsight as it viewed the map were then relayed to the aircraft as if the bombsight were on board (e.g., to a 1945 AN/ARA-17 Release Point Indicator).

Post-war In Western usage, the phrase post-war era (or postwar era) usually refers to the time since the end of World War II. More broadly, a post-war period (or postwar period) is the interval immediately following the end of a war. A post-war period ...

, ground radar

was common for missiles designed to bombard ground targets, such as the AN/MSQ-1A with

alternating current Alternating current (AC) is an electric current which periodically reverses direction and changes its magnitude continuously with time in contrast to direct current (DC) which flows only in one direction. Alternating current is the form in whic ...

analog computer initially used for guidance of the MGM-1 Matador (the

Republic-Ford JB-2 The Republic-Ford JB-2, also known as the Thunderbug, KGW and LTV-N-2 Loon, was a United States copy of the German V-1 flying bomb. Developed in 1944, and planned to be used in the United States invasion of Japan (Operation Downfall), t ...

Loon had used ground radar guidance in 1945, and a few

V-2 The V-2 (german: Vergeltungswaffe 2, lit=Retaliation Weapon 2), with the technical name ''Aggregat 4'' (A-4), was the world’s first long-range guided ballistic missile. The missile, powered by a liquid-propellant rocket engine, was develope ...

s bombarding England used radio control in 1944.)

Korean War

Korean War {{Infobox military conflict , conflict = Korean War , partof = the Cold War and the Korean conflict , image = Korean War Montage 2.png , image_size = 300px , caption = Clockwise from top:{ ...

GDB equipment of the

United States Marine Corps The United States Marine Corps (USMC), also referred to as the United States Marines, is the maritime land force service branch of the United States Armed Forces responsible for conducting expeditionary and amphibious operations through c ...

included the AN/MPQ-14, and GBD in Korea "was first tried on November 28 950 when a detachment of the

3903d Radar Bomb Scoring Squadron 39 may refer to: * 39 (number), the natural number following 38 and preceding 40 * one of the years: ** 39 BC ** AD 39 ** 1939 ** 2039 * ''39'' (album), a 2000 studio album by Mikuni Shimokawa * "'39", a 1975 song by Queen * "Thirty Nine", a song ...

used truck-mounted AN/MPQ-2 radars erived_from_the_World_War_II_ erived_from_the_World_War_II_SCR-584_gun_laying_set">SCR-584.html"_;"title="erived_from_the_World_War_II_SCR-584">erived_from_the_World_War_II_SCR-584_gun_laying_setto_guide_ erived_from_the_World_War_II_SCR-584_gun_laying_set">SCR-584.html"_;"title="erived_from_the_World_War_II_SCR-584">erived_from_the_World_War_II_SCR-584_gun_laying_setto_guide_Martin_B-26_Marauder">B–26s_against_enemy_positions_in_front_of_the_25th_Infantry_Division_(United_States).html" ;"title="Martin_B-26_Marauder.html" ;"title="SCR-584_gun_laying_set.html" ;"title="SCR-584.html" ;"title="erived from the World War II SCR-584">erived from the World War II SCR-584 gun laying set">SCR-584.html" ;"title="erived from the World War II SCR-584">erived from the World War II SCR-584 gun laying setto guide Martin B-26 Marauder">B–26s against enemy positions in front of the 25th Infantry Division (United States)">25th Infantry Division." Three USAF RBS detachments (e.g., Det 5) commanded GDB until the 502nd Tactical Control Group "assumed control of the 3903's three MPQ-2 radar sets" in January 1951, and the radar sites "became full-scale tactical air-direction posts called Tadpoles [code]-named Hillbilly, Beverage, and Chestnut,…about ten miles behind the front lines near the command posts of the I, IX, and X Corps." On February 23, 1951, the 1st

Boeing B-29 Superfortress The Boeing B-29 Superfortress is an American four-engined propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to its predecessor, the B-17 Fl ...

mission controlled by an MPQ-2 was flown, and a new

AN/MSQ-1 Close Support Control Set The Reeves AN/MSQ-1 Close Support Control Set produced by Reeves Instrument Corporation was a trailer-mounted http://radar.tpub.com/TM-11-487C-1/TM-11-487C-10445.htm ""Close Support Control Set AN/MSQ-1 directs aircraft for close-support bombing m ...

was at Yangu, Korea, by September 1951 ( AN/MPS-9 with OA-132 plotting computer & board). The similar AN/MSQ-2 Close Support Control Set also developed by Rome Air Development Center (MPS-9 radar & OA-215)http://webcache.googleusercontent.com/search?q=cache:_DNZybImKTIJ:groups.yahoo.com/group/combatevaluationgroup/message/23682+%22The+first+AN/MSQ-77+came+from+Richmond%22&hl=en&gl=us&prmd=imvns&strip=1 began arriving in 1951 (in October, one GDB detachment that hadn't been provided MSQ-2 Technical Orders mistakenly bombed itself by using MSQ-1 procedures.) Korea GDB operations of 2380 & 204 respective daylight & nighttime raids included 900 flown by USMC

Vought F4U Corsair The Vought F4U Corsair is an American fighter aircraft which saw service primarily in World War II and the Korean War. Designed and initially manufactured by Chance Vought, the Corsair was soon in great demand; additional production contract ...

Vietnam War

GDB equipment included the USMC AN/TPQ-10 "Course Directing Central" and the

United States Air Force The United States Air Force (USAF) is the air 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 of the United States Army Si ...

"Bomb Directing Centrals" with bomb ballistics computer by Reeves Instrument Corporation ( AN/MSQ-77, AN/TSQ-81, & AN/TSQ-96) for

Combat Skyspot Combat Skyspot was the ground-directed bombing (GDB) operation of the Vietnam War by the United States Air Force using Bomb Directing Centrals and by the United States Marine Corps using Course Directing Centrals (" MSQ-77 and TPQ-10 ground ra ...

. From 1966-1971, ASRTs controlled more than 38,010 AN/TPQ-10 missions, directing more than 121,000 tons of ordnance on 56,753 targets (e.g., during the USMC "Operation Neutralize" bombing campaign against the North Vietnamese' siege of "Con Thien"). NOTE: Lake 2004, p. 48, mistakenly says the "normal limit (with two ''Skyspot'' beacons) was 3300 yards from friendly forces", but TACAN used multiple beacons, not Skyspot--which used only one radar even if a non-transmitting Skyspot backup receiving the A/C transponder returns tracked or later commanded the bomb run. In addition to Arc Light B-52 airstrikes, GDB during the war was used against Cambodia targets of Operation Menu from

Bien Hoa Air Base Bien Hoa Air Base ( Vietnamese: ''Sân bay Biên Hòa'') is a Vietnam People's Air Force (VPAF) military airfield located in South-Central southern Vietnam about from Ho Chi Minh City, across the Dong Nai river in the northern ward of Tân Pho ...

and by

Operation Niagara Operation Niagara was a U.S. Seventh Air Force close air support campaign carried out from January through March 1968, during the Vietnam War. Its purpose was to serve as an aerial umbrella for the defense of the U.S. Marine Corps Khe Sanh Comb ...

, while Commando Club was used for GDB of the

Red River Delta The Red River Delta or Hong River Delta ( vi, Châu thổ sông Hồng) is the flat low-lying plain formed by the Red River and its distributaries merging with the Thái Bình River in northern Vietnam. ''Hồng'' (紅) is a Sino-Vietnamese word ...

(e.g.,

Hanoi Hanoi or Ha Noi ( or ; vi, Hà Nội ) is the capital and second-largest city of Vietnam. It covers an area of . It consists of 12 urban districts, one district-leveled town and 17 rural districts. Located within the Red River Delta, Hanoi i ...

Late Cold War

Post-Vietnam War GDB

Strategic Air Command Strategic Air Command (SAC) was both a United States Department of Defense Specified Command and a United States Air Force (USAF) Major Command responsible for command and control of the strategic bomber and intercontinental ballistic missile ...

missions were occasionally used for training/readiness, e.g., to maintain proficiency of aircrews and SAC's GDB-qualified technicians at

1st Combat Evaluation Group The 1st Combat Evaluation Group (initially "1CEG", later "1CEVG") was a Strategic Air Command (SAC) unit. It was formed on 1 August 1961 to merge the 3908th Strategic Standardization Group for SAC aircrew evaluation with the 1st Radar Bomb Sco ...

RBS sites. A new GBD system developed from the AN/TPB-1C Course Directing Central was the solid-state US Dynamics AN/TPQ-43 Bomb Scoring Set

which included optical trackin

The AN/TPQ-43 ("Seek Score") replaced the AN/MSQ-77, -81, & -96 systems at the end of the

Cold War The Cold War is a term commonly used to refer to a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc. The term '' cold war'' is used because t ...

before being decommissioned in 2007, and GDB systems were also designated for use during

airdrop An airdrop is a type of airlift in which items including weapons, equipment, humanitarian aid or leaflets are delivered by military or civilian aircraft without their landing. Developed during World War II to resupply otherwise inaccessible tr ...

s as part of the Ground Radar Aerial Delivery System (GRADS).http://www.e-publishing.af.mil/shared/media/epubs/AFI11-231.pdf

Iraq War

References

{{Reflist Aerial operations and battles of World War II involving the United States Aerial warfare tactics Cold War tactics Military operations of the Korean War Military operations of the Vietnam War Military radars Science and technology during World War II World War II operations and battles of the Italian Campaign Aerial operations and battles of the Korean War Aerial operations and battles of the Vietnam War