View source for Ground-directed bombing

{{For|bombing directed by ''airborne'' [[Forward Air Controller]]s (FAC-A)|Forward air control#War of movement}}
{{Cleanup bare URLs|date=August 2022}}
'''Ground-directed bombing''' (GDB) is a military tactic for [[airstrike]]s by [[ground-attack aircraft]], [[strategic bombers]], and other equipped air vehicles under [[command guidance]] from [[aviation ground support equipment]] and/or ground personnel (e.g., [[Forward Air Controller|ground observers]]).   Often used in poor weather and at night (75% of all [[Vietnam War]] bombings "were done with {{sic|precision}} GDB"),<ref>{{Cite web |date=January 9, 1999 |title=AN/MSQ-77 |url=https://www.fas.org/man/dod-101/sys/ac/equip/an-msq-77.htm |work=FAS Military Analysis Network: Equipment |publisher=[[Federation of American Scientists]] |accessdate=2012-07-17}}</ref> the tactic was superseded by an airborne computer predicting unguided bomb impact from data provided by precision avionics (e.g., [[Global Positioning System|GPS]], [[GPS/INS]], etc.)  Equipment for radar GDB generally included a combination ground radar/computer/communication system ("Q" system) and aircraft avionics for processing radioed commands.<ref>GDB radar/computer systems were also used for [[Radar Bomb Scoring]] (RBS) during the [[Cold War]] until avionics with GPS accuracy were equipped to transmit a record of an unguided bomb's release point, airspeed, groundspeed, etc. for "no-drop bomb scoring" (e.g., [[Northrop T-38]]C in 2007).{{cite web|url=http://www.sheppard.af.mil/shared/media/document/AFD-120424-057.pdf |title=Archived copy |accessdate=September 23, 2012 |url-status=dead |archiveurl=https://web.archive.org/web/20120809084412/http://www.sheppard.af.mil/shared/media/document/AFD-120424-057.pdf |archivedate=August 9, 2012 }}</ref>

A 21st century variant of ground-directed bombing is the radio [[command guidance]] for armed [[unmanned aerial vehicle]]s to effect ground-directed release of ordnance (e.g., [[precision-guided munition]]s for bombing such as the [[AGM-114 Hellfire]]).<ref>{{Cite web|url=https://www.military.com/NewContent/0,13190,NI_0705_Air-P2,00.html|title=Close Air Support Using Armed UAVs? - Page 2|website=www.military.com|access-date=2016-04-18}}</ref>

==World War II==
In early 1945, ground-directed bombing was invented by Lt Col Reginald Clizbe, deputy commander of the [[47th Bombardment Group]] (Light), using automatic tracking radar in Northern Italy for [[Douglas A-26 Invader|A-26C]] missions (e.g., in the [[Po Valley]]).<ref name=Akers/>  Development was by a team that included Donald H. Falkingham (who was awarded the Air Medal)<ref>{{cite web |last1=Falkingham |first1=Donald H. |title=Donald Falkingham A-26 And A-20 |url=http://www.worldwar2pilots.net/AAF-B-Falkingham-A20-1.htm |website=World War II Pilots |archive-url=https://web.archive.org/web/20110131100238/http://www.worldwar2pilots.net/AAF-B-Falkingham-A20-1.htm |archive-date=January 31, 2011 |url-status=dead}}</ref> that modified radar plotting to transmit control commands to the [[pilot direction indicator]] (bomb release was eventually automated from the ground radar).<ref name=Akers>{{Citation |last=Akers |first=Marion |title=Unique Radar Bombing Technique |url=https://books.google.com/books?id=DmRitcvHAEoC&q=%22Release+Point+Indicator%22+%22plotting+board%22&pg=PA32 |format=anecdote within book  |work=[[47th Bombardment Group]] (L) |year=1996 |publisher=[[Turner Publishing Company]] |isbn=9781563112409 |accessdate=2012-05-26 |quote=''Won his first Air Medal while working with Col. Clizby in developing a means to bomb close support to the troops using ground control radar.''}}  '''NOTE''': "bombing by radar-control" is identified in a "19 February 1945" listing of the Combat Chronology.[https://www.ww2aircraft.net/forum/ww2-general/day-war-europe-65-years-ago-6116-90.html]</ref> Similar to the ground training configuration in the US for bombardiers with the [[Norden bombsight]], in a tent near the [[SCR-284]] radar<ref>{{cite web |url=http://groups.google.com/group/alt.military.retired/browse_thread/thread/6c15a91e9a7c2a5b/bbe793e2e6ad5adb |title=Trivia Question - alt.military.retired &#124; Google Groups |website=groups.google.com |access-date=2 February 2022 |archive-url=https://archive.today/20120710153015/http://groups.google.com/group/alt.military.retired/browse_thread/thread/6c15a91e9a7c2a5b/bbe793e2e6ad5adb |archive-date=10 July 2012 |url-status=dead}}</ref> 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''').<ref>{{Cite book|url=https://books.google.com/books?id=Agt5HAAACAAJ|title=Preliminary Operation and Maintenance Handbook for Release Point Indicator AN/ARA-17|date=1945-01-01|publisher=Radiation Laboratory, Massachusetts Institute of Technology|language=en}}</ref>

[[Post-war]], ground radar [[command guidance]] was common for missiles designed to bombard ground targets, such as the AN/MSQ-1A with [[alternating current]] analog computer initially used for guidance of the [[MGM-1 Matador]]<ref>{{cite web |url=http://groups.yahoo.com/group/combatevaluationgroup/messages/32012?threaded=1&m=e&var=1&tidx=1 |title=Combatevaluationgroup : Messages : 3206-32012 of 100260 |website=groups.yahoo.com |access-date=2 February 2022 |archive-url=https://archive.today/20121209165342/http://webcache.googleusercontent.com/search?q=cache:nxSMJM6zK_4J:groups.yahoo.com/group/combatevaluationgroup/messages/32012?threaded%3D1%26m%3De%26var%3D1%26tidx%3D1+clayton+cevg+navy+matador&cd=1&hl=en&ct=clnk&gl=us |archive-date=9 December 2012 |url-status=dead }}</ref> (the [[Republic-Ford JB-2]] Loon had used ground radar guidance in 1945,<ref>{{Cite web | url=https://www.designation-systems.net/dusrm/app1/ltv-n-2.html | title=Willys-Overland LTV-N-2 Loon }}</ref> and a few [[V-2]]s bombarding England used radio control in 1944.)

==Korean War==
[[Korean War]] GDB equipment of the [[United States Marine Corps]] included the AN/MPQ-14, and GBD in Korea "was first tried on November 28 [1950], when a detachment of the [[3903d Radar Bomb Scoring Squadron]] used [[AN/MPQ-2 Close Cooperation Control Unit|truck-mounted AN/MPQ-2 radars]] [derived from the World War II [[SCR-584]] gun laying set]<ref>https://www.radomes.org/museum/guestbook.php?guestfile=2004/guest200407.txt (see also [https://archive.today/20121209151340/http://webcache.googleusercontent.com/search?q=cache:lacbqczHkdMJ:groups.yahoo.com/group/combatevaluationgroup/message/12333+%22The+Migs+jumped+the+bomber+stream+%22&cd=6&hl=en&ct=clnk&gl=us Yahoo posting 12333)]</ref> to guide [[Martin B-26 Marauder|B–26]]s against enemy positions in front of the [[25th Infantry Division (United States)|25th Infantry Division]]."<ref name=afhso2>{{Cite web |url=http://www.afhso.af.mil/shared/media/document/AFD-100526-023.pdf |title=Archived copy |access-date=2012-10-26 |archive-date=2011-11-27 |archive-url=https://web.archive.org/web/20111127123557/http://www.afhso.af.mil/shared/media/document/AFD-100526-023.pdf |url-status=dead }}</ref>  Three USAF RBS detachments (e.g., Det 5)<ref>{{Cite web | url=http://www.koreanwar.org/html/units1/usaf/3903rbs.htm | title=Legacy Files - 3903rd Radar Bomb Scoring Group - USAF - Korean War Project }}</ref> commanded GDB until the [[502nd Tactical Control Group]] "assumed control of the 3903's three MPQ-2 radar sets" in January 1951,<ref name=607ACW/> 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."{{r|afhso2}}  On February 23, 1951, the 1st [[Boeing B-29 Superfortress]] mission controlled by an MPQ-2 was flown,<ref>{{usurped|1=[https://web.archive.org/web/20091211073305/http://www.airforce-magazine.com/MagazineArchive/Pages/2000/October%202000/1000korea.aspx Article title]}}</ref> and a new {{who|who was the manufacturer?|date=July 2012}}[[AN/MSQ-1 Close Support Control Set]] was at [[Yangu, Korea]], by September 1951<ref>{{Cite web |url=http://www.607acw.org/History.html |title=History |access-date=2012-10-26 |archive-url=https://web.archive.org/web/20120615021139/http://www.607acw.org/History.html |archive-date=2012-06-15 |url-status=usurped }}</ref> ([[AN/MPS-9]] with OA-132 plotting computer & board).{{r|message23682}}  The similar {{who|who was the manufacturer?|date=July 2012}}[[AN/MSQ-2 Close Support Control Set]] also developed by [[Rome Air Development Center]]<ref>[https://apps.dtic.mil/sti/pdfs/ADA250435.pdf Article title]</ref> (MPS-9 radar & OA-215)<ref name=message23682>[http://groups.yahoo.com/group/combatevaluationgroup/message/23682 ]{{dead link|date=July 2016 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> began arriving in 1951 (in October,<ref>{{Cite web|url=http://www.afhso.af.mil/shared/media/document/AFD-090814-035.pdf|title=Air Force Historical Support Division > Home|access-date=2012-10-26|archive-date=2013-02-11|archive-url=https://web.archive.org/web/20130211025818/http://www.afhso.af.mil/shared/media/document/AFD-090814-035.pdf|url-status=dead}}</ref> one GDB detachment that hadn't been provided MSQ-2 Technical Orders mistakenly bombed itself by using MSQ-1 procedures.)<ref>{{Cite web |title=3903rd Radar Bomb Scoring Group |url=http://www.koreanwar.org/html/units/usaf/3903rbs.htm |format=Web [[Bulletin Board]] |publisher=KoreanWar.org |accessdate=2012-05-20 |quote=''On the MSQ-1, we operated in the same manner, but later learned that [for the "brand new MSQ-2 plotting equipment"] we should have entered the target coordinates into the new digital/analog computer, AND THEN 'ZEROED' THEM OUT AGAIN. The computer would remember the offset and track accordingly. Unfortunately, we did not know that without the TO's. By leaving them in, like the 584, we effectively located the target's position over the top of ourselves.''}}</ref>  Korea GDB operations of 2380 & 204 respective daylight & nighttime raids included 900 flown by USMC [[Vought F4U Corsair]]s.<ref name=607ACW>{{Cite web |url=http://www.607acw.org/tadpoles.html |title=Tadpoles |access-date=2012-09-23 |archive-url=https://web.archive.org/web/20120204085133/http://www.607acw.org/tadpoles.html |archive-date=2012-02-04 |url-status=usurped }}</ref>

==Vietnam War==
{{Main|Combat Skyspot}}
[[Vietnam War]] GDB equipment included the USMC [[AN/TPQ-10]] "Course Directing Central" and the [[United States Air Force]] "Bomb Directing Centrals" with bomb ballistics computer by [[Reeves Instrument Corporation]] ([[Reeves AN/MSQ-77 Bomb Directing Central|AN/MSQ-77]], [[Reeves AN/TSQ-81 Bomb Directing Central|AN/TSQ-81]], & [[Reeves AN/TSQ-96 Bomb Directing Central|AN/TSQ-96]]) for [[Combat Skyspot]].  From 1966-1971, [[ASRT]]s controlled more than 38,010 AN/TPQ-10 missions, directing more than 121,000 tons of ordnance on 56,753 targets<ref>from [[Direct Air Support Center]] wikipage</ref> (e.g., during the USMC "Operation Neutralize" bombing campaign against the North Vietnamese' [[Con Thien#Bombardment|siege of "Con Thien"]]).<ref name=Schlight>{{Cite book |last=Schlight |first=John |year=1999 |title=The War in South Vietnam: The Years of the Offensive (1965-1968) |url=http://www.afhso.af.mil/shared/media/document/AFD-101013-038.pdf |archive-url=https://web.archive.org/web/20111127165157/http://www.afhso.af.mil/shared/media/document/AFD-101013-038.pdf |url-status=dead |archive-date=November 27, 2011 |series=The United States Air Force in Southeast Asia |pages=269–271 |accessdate=2012-06-16}}  '''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.</ref>  In addition to [[Operation Arc Light|Arc Light]] B-52 airstrikes, GDB during the war was used against Cambodia targets of [[Operation Menu]] from [[Bien Hoa Air Base]] and by [[Operation Niagara]],<ref name=Morocco>{{Cite book |last=Morocco |first=John |year=1985 |title=Rain of Fire: Air War, 1969–1973 |location=Boston |publisher=Boston Publishing Company |page=14}}</ref> while [[Commando Club]] was used for GDB of the [[Red River Delta]] (e.g., [[Hanoi]]).

==Late Cold War==
Post-Vietnam War GDB [[Strategic Air Command]] 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]] RBS sites.  A new GBD system developed {{circa|lk=no|1980}} from the {{who|who was the manufacturer?|date=July 2012}}[[AN/TPB-1C Course Directing Central]] was the solid-state [[US Dynamics AN/TPQ-43 Bomb Scoring Set]][https://www.globalsecurity.org/military/systems/aircraft/systems/an-tpq-43.htm] which included optical tracking.[https://web.archive.org/web/20160116214235/http://reocities.com/pentagon/quarters/3996/tpq-43.html]  The AN/TPQ-43 ("Seek Score") replaced the AN/MSQ-77, -81, & -96 systems at the end of the [[Cold War]]<ref>{{Cite report |last=Jost |first=Alan C. |year=2007 |title=ConOps:The Cryptex to Operational System Mission Success |url=http://www.crosstalkonline.org/storage/issue-archives/2007/200710/200710-Jost.pdf |location=[[Raytheon]] |accessdate=2012-07-09 |archive-date=2012-08-05 |archive-url=https://web.archive.org/web/20120805211741/http://www.crosstalkonline.org/storage/issue-archives/2007/200710/200710-Jost.pdf |url-status=dead }}</ref> before being decommissioned in 2007,<ref>[http://dir.groups.yahoo.com/group/combatevaluationgroup/message/41816 ]{{dead link|date=July 2016 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> and GDB systems were also designated for use during [[airdrop]]s as part of the Ground Radar Aerial Delivery System (GRADS).<ref>[http://www.e-publishing.af.mil/shared/media/epubs/AFI11-231.pdf af.mil]{{dead link|date=March 2025|bot=medic}}{{cbignore|bot=medic}}</ref>

==Iraq War==
{{Expand section|info similar to that in the [[Direct Air Support Center]] article, but with citations|date=October 2012}}

==References==
{{Reflist}}

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