The Permanent System ("P system") was a 1950s radar network ("P radar net") used for the CONUS "manual air defense system" and which had a USAF aircraft control and warning (AC&W) organization of personnel and military installations with radars to allow

Air Defense Command Aerospace Defense Command was a major command (military formation), command of the United States Air Force, responsible for air defense of the continental United States. It was activated in 1968 and disbanded in 1980. Its predecessor, Air De ...

ground-controlled interception Ground-controlled interception (GCI) is an air defence tactic whereby one or more radar stations or other observational stations are linked to a command communications centre which guides interceptor aircraft to an airborne target. This tactic wa ...

Cold War The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 unt ...

bombers attacking the United States.

Planning

During

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

the

United States Army The United States Army (USA) is the primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of th ...

organized a network of "Army Radar Stations",

Aircraft Warning Corps The Aircraft Warning Corps (AWC) was a World War II United States Army Air Force organization for Continental United States air defense. The corps' information centers networked an area's "Army Radar Stations" which communicated radar tracks b ...

information centers,

Ground Observer Corps The Ground Observer Corps (GOC), sometimes erroneously referred to as the Ground ''Observation'' Corps, was the name of two American civil defense organizations during the middle 20th century. World War II organization The first Ground Observer ...

filter centers, and Fighter Control Centers (which were "inactivated...in April 1944") to provide air defence. A similar post-war system was planned. The

Distant Early Warning Line The Distant Early Warning Line, also known as the DEW Line or Early Warning Line, was a system of radar stations in the northern Arctic region of Canada, with additional stations along the north coast and Aleutian Islands of Alaska (see List o ...

was "first conceived—and rejected—in 1946." General Stratemeyer forwarded an air defense plan to General Spaatz in November 1946. In the spring and summer of 1947, three

Aircraft Control and Warning (AC&W) plans went unfunded. e.g., the 8 April 1947, "air defense plan (long term)". With only 5 "Air Warning Station" radars operating in 1948, the "Radar Fence Plan (

code name A code name, codename, call sign, or cryptonym is a code word or name used, sometimes clandestinely, to refer to another name, word, project, or person. Code names are often used for military purposes, or in espionage. They may also be used in ...

d Project SUPREMACY)" was planned for completion by 1953 with 411 radar stations and 18 control centers. The

Radar Fence Radar is a system that uses radio waves to determine the distance (''ranging''), direction (azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track aircraf ...

was rejected by ADC since "no provision was made in it for the Alaska to Greenland net with flanks guarded by aircraft and

radar picket A radar picket is a radar-equipped station, ship, submarine, aircraft, or vehicle used to increase the radar detection range around a nation or military (including naval) force to protect it from surprise attack, typically air attack, or from c ...

ships equiredfor 3 to 6 hours of warning time" (the Alaska to Greenland net was eventually built as the

). ADC's Interim Program and its First Augmentation were planned "until the Supremacy plan network could be approved and constructed", and an $85,500,000 March 1949 Congressional bill funded both the Interim Program "for 61 basic radars and 10 control centers to be deployed in 26 months, with an additional ten radars and one control station for Alaska" and the augmentation's additional 15 radars ("essentially Phase II of Supremacy"). The resulting

Lashup Radar Network The Lashup Radar Network was a United States Cold War radar netting system for air defense surveillance which followed the post-World War II "five-station radar net" and preceded the "high Priority Permanent System". ROTOR was a similar expedient ...

was completed in April 1950 and was operational in June 1950. On 13 February 1950, HQ USAF had "advanced the completion date from July 1, 1951, to December 31, 1950, for the most essential radar stations. The USAF reallocated $50 million for the "permanent Modified Plan" (modified from Supremacy) to "start construction on the high Priority Permanent System of radars in February 1950 with the first 24 radar sites to be constructed by the end of 1950". Early June 1950 exercises "in the 58th Air Division bd Lashup sitesindicated insufficient low-altitude coverage," and the Secretary of the Air Force requested a 2nd stage of 28 stations on 11 July 1950 (Secretary of Defense approval was on 21 July.) By November 1950,

Ground Observation Corps The Ground Observer Corps (GOC), sometimes erroneously referred to as the Ground ''Observation'' Corps, was the name of two American civil defense organizations during the middle 20th century. World War II organization The first Ground Observer ...

filter centers (7 in the west, 19 in the east) were being installed. By 10 November a separate Air Defense Command headquarters was approved, the

Federal Civil Defense Administration The Federal Civil Defense Administration (FCDA) was organized by President Harry S. Truman on December 1, 1950, through Executive Order 10186, and became an official government agency via the Federal Civil Defense Act of 1950 on 12 January 1 ...

was created in December 1950, and command centers communicated radar track information to the national ADC center that had moved from Mitchell Field to

Ent Air Force Base Ent Air Force Base was a United States Air Force base located in the Knob Hill neighborhood of Colorado Springs, Colorado. A tent city, established in 1943 during construction of the base, was initially commanded by Major General Uzal Girar ...

on 8 January 1951.

Description

The "original construction program for the Permanent System" was completed in May 1952, USAF AC&W squadrons were established (renamed Radar Squadrons in the mid-1950s), and the

was expanded in 1952 ( Operation Skywatch) with over 750,000 volunteers at over 16 thousand posts (98 per post in shifts) and 75 centers.

Manual Air Defense Control Centers

Manual Air Defense Control Centers (ADCC, MCC) of the Permanent System were

USAF The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...

command posts for command, control, and coordination by

, including early

of enemy aircraft. Each MCC networked radar stations of the sector, plotted radar tracks & visual observations, and forwarded information to ADC command center at

Mitchel Field Mitchell may refer to: People and fictional characters *Mitchell (surname), including lists of both people and fictional characters *Mitchell (given name), lists of people and fictional characters Places Australia * Mitchell, Australian Ca ...

in 1951, and the new 1954 Ent blockhouse subsequently used by the 1954

CONAD Conad (', English: ''National Retailers Consortium''), stylized CONAD, is an Italian retail store brand which operates one of the largest supermarket chains in Italy. History Created in 1962, Conad is a cooperative system of entrepreneurs, ...

and the 1957

NORAD North American Aerospace Defense Command (NORAD ; , CDAAN), known until March 1981 as the North American Air Defense Command, is a combined organization of the United States and Canada that provides aerospace warning, air sovereignty, and pr ...

. MCCs were generally located at or near a radar station, e.g.,

Andrews Air Force Base Andrews Air Force Base (Andrews AFB, AAFB) is the airfield portion of Joint Base Andrews, which is under the jurisdiction of the United States Air Force (USAF). In 2009, Andrews Air Force Base merged with Naval Air Facility Washington to form ...

MCC in Maryland (at/near radar station SM-171),

Dobbins AFB Dobbins Air Reserve Base or Dobbins ARB is a United States Air Force reserve air base located in Marietta, Georgia, a suburb about northwest of Atlanta. Originally known as Dobbins Air Force Base, it was named in honor of Captain Charles M ...

GA (M-87),

Geiger Field Spokane International Airport is a commercial airport in Spokane, Washington, United States, located approximately west-southwest of Downtown Spokane. It is the primary airport serving the Inland Northwest, which consists of 30 counties and ...

WA (SM-172),

Kirtland AFB Kirtland Air Force Base is a United States Air Force base. It is located in the southeast quadrant of the Albuquerque, New Mexico, urban area, adjacent to the Albuquerque International Sunport. The base was named for the early Army aviator C ...

NM (P-41), Norton AFB CA (P-84), Oklahoma City AFS OK (P-52), Roslyn AFS NY (P-3), Snelling AFS MN (P-36),

Willow Run AFS Willow Run Air Force Station is a former United States Air Force station that operated to the east of Willow Run Airport in Michigan. History In 1951, the United States Air Force exercised a right of return to Willow Run and established Willow ...

MI (P-23), and

Wright-Patterson AFB Wright-Patterson Air Force Base (WPAFB) is a United States Air Force base and census-designated place just east of Dayton, Ohio, in Greene and Montgomery counties. It includes both Wright and Patterson Fields, which were originally Wilbur Wr ...

OH (SM-170). Some MCCs were replaced by Direction Centers of the subsequent SAGE Radar Network, e.g., when McGuire DC-01 was established, the Roslyn Air Force Station MCC became the "Combat Alert Center (Manual)". MCCs continued at several sites where DCs were planned but never built for sectors at

Albuquerque Albuquerque ( ; ), also known as ABQ, Burque, the Duke City, and in the past 'the Q', is the List of municipalities in New Mexico, most populous city in the U.S. state of New Mexico, and the county seat of Bernalillo County, New Mexico, Bernal ...

Fort Knox Fort Knox is a United States Army installation in Kentucky, south of Louisville and north of Elizabethtown, Kentucky, Elizabethtown. It is adjacent to the United States Bullion Depository (also known as Fort Knox), which is used to house a larg ...

Kansas City The Kansas City metropolitan area is a bi-state metropolitan area anchored by Kansas City, Missouri. Its 14 counties straddle the border between the U.S. states of Missouri (9 counties) and Kansas (5 counties). With and a population of more t ...

Miami Miami is a East Coast of the United States, coastal city in the U.S. state of Florida and the county seat of Miami-Dade County, Florida, Miami-Dade County in South Florida. It is the core of the Miami metropolitan area, which, with a populat ...

Raleigh Raleigh ( ) is the List of capitals in the United States, capital city of the U.S. state of North Carolina. It is the List of municipalities in North Carolina, second-most populous city in the state (after Charlotte, North Carolina, Charlotte) ...

San Antonio San Antonio ( ; Spanish for " Saint Anthony") is a city in the U.S. state of Texas and the most populous city in Greater San Antonio. San Antonio is the third-largest metropolitan area in Texas and the 24th-largest metropolitan area in the ...

Shreveport Shreveport ( ) is a city in the U.S. state of Louisiana. It is the List of municipalities in Louisiana, third-most populous city in Louisiana after New Orleans and Baton Rouge, Louisiana, Baton Rouge. The bulk of Shreveport is in Caddo Parish, Lo ...

, and

St Louis St. Louis ( , sometimes referred to as St. Louis City, Saint Louis or STL) is an Independent city (United States), independent city in the U.S. state of Missouri. It lies near the confluence of the Mississippi River, Mississippi and the Miss ...

. ;Filter Centers: Filter Centers of the

(e.g., i
New Haven, Connecticut
and

Baltimore, Maryland Baltimore is the List of municipalities in Maryland, most populous city in the U.S. state of Maryland. With a population of 585,708 at the 2020 United States census, 2020 census and estimated at 568,271 in 2024, it is the List of United States ...

). processed reports from ~8,000 CONUS watch posts. As with ranger stations for forest fires, watch posts measured the azimuth of a target aircraft or formation, and Filter Centers triangulated azimuth observations from 2 or more stations, assessed the reliability of observations, and provided visual track information to MCCs.

Radar stations

Five radar stations of the

were redesignated as Permanent System stations (3 later upgraded with newer radars developed for the Permanent System): Montauk L-10/LP-45/P-45, Fort Custis L-15/LP-56, Palermo L-13/LP-54/P-54, Sault Sainte Marie L-17/LP-20, and Highlands L-12/LP-9/P-9. From March to November 1951, the "LP" designation was also used for 23 new stations for the Permanent System that were outfitted, instead of with radars developed for the Permanent System, with older radars such as the January 1945 General Electric

AN/CPS-5 The AN/FPS-20 was a widely used L band early warning and ground-controlled interception radar system employed by the United States Air Force Air Defense Command, the NORAD Pinetree Line in Canada, the USAF CONAD in the continental United States ...

radar, 1948 Western Electric AN/TPS-1B Radar, and Bendix AN/TPS-1C radar.MX-1000 to MX-1499 Listing
Designation-systems.net (2005-11-20). Retrieved on 2013-09-18. The LP designator was also used for 1 station opened with

AN/FPS-3 The AN/FPS-20 was a widely used L band early warning and ground-controlled interception radar system employed by the United States Air Force Air Defense Command, the NORAD Pinetree Line in Canada, the USAF CONAD in the continental United State ...

and AN/FPS-5 radars in 1950 ( Tierra Amarilla LP-8). More than 15 of the new LP stations were subsequently upgraded and designated P-xx stations, and some of the squadrons at LP stations that closed moved to new P stations. New LP sites not previously designated L sites: * Bellefontaine LP-73/P-73 (TPS-1B in November 1951), *Blue Knob LP-63 (TPS-1C 30 November 1951—station moved to Gibbsboro RP-63 in 1961), * Cambria LP-2/P-2 (TPS-1C November 1951) * Caswell LP-80/P-80 (TPS-1B March 1951), * Colville LP-60/P-60 (TPS-1B March 1951, TPS-1C November 1951), * Condon LP-32/P-32 (TPS-1C November 1951), * Curlew LP-6/P-6 Mt Bonaparte TPS-1B 1950 * Del Bonita LP-24 (TPS-1B November 1951) (P-24 is Cut Bank AFS), * Williams Bay AFS Elkhorn LP-31 (moved to RP-31 at Arlington Heights AFS), * Finland LP-69/P-69 (CPS-5 30 November 1951), * Fort Custer LP-67/P-67 (TPS-1B 30 November 1951), * Godman Field LP-82 (TPS-1C 30 April 1952) (P-82 Snow Mountain AFS), *Gonzales LP-7 (P-7 Continental Divide AFS), *Hill Peak Road LP-37 (P-37 Point Arena AFS), *Keweenaw LP-16 (P-16 Calumet AFS), * Klamath LP-33/P-33 TPS-1B (Apr 51) * Madera LP-74/P-74 (TPS-1B in March 51), * Moriarty LP-51/P-51 CPS-5 (30 Nov 51) * Port Austin LP-61/P-61 TPS-1C 30-Nov-51 * Rockville LP-53/P-53 TPS-1B (30 Nov 51) *Saddle Mountain/ Othello LP-40/P-40 TPS-1B * San Clemente Island LP-39/P-39 TPS-1C Nov-51 * Tierra Amarilla LP-8/P-8 FPS-3; FPS-5; 1950 Permanent System radars were developed in various programs such as the AN/FPS-6 (in program MX-1353 - "Long range S-band height finder") and AN/MPS-10 (MX-1354 - "Mobile long range search radar set"). ;Priority Permanent System: The "Priority Permanent System" with the initial (priority) radar stations having new radar systems included " ADC radar site" P-1 at McChord AFB on 1 June 1950. Completed in May 1952 to replace the 1950

, the Priority Permanent System had 5 redesignated LASHUP stations, 23 new stations in 1951 with older radars, 62 stations in 1951 with new equipment, and several of the 10 newly equipped 1952 stations (including Manassas RP-55). The Priority Permanent System used Manual ADCCs, e.g., with

Plexiglas Poly(methyl methacrylate) (PMMA) is a synthetic polymer derived from methyl methacrylate. It is a transparent thermoplastic, used as an engineering plastic. PMMA is also known as acrylic, acrylic glass, as well as by the trade names and bra ...

plotting boards as at the 1954

command center for ADC. ;P system extension: The "first extension of the P system into Canada" ("Canadian extensions") for the

Pinetree Line The Pinetree Line was a series of radar stations located across southern Canada at about the 50th parallel north, along with a number of other stations located on the Atlantic and Pacific coasts. Run by North American Aerospace Defense Comm ...

was planned by the "Radar Extension Program" for 33 stations and was agreed by the US and Canada in November 1950. The plan "was submitted to the Permanent Joint Board on Defense on February 6, 1951, and" was subsequently approved by both nations, but by "April 1951 the United States still had not contributed to the Radar Extension Program". On 13 June 1951, the US released $20 million for the stations and by June 1952, the joint Canadian-American committee on the Radar Extension Program was replaced with the "Project Pinetree Office" in

Ottawa, Ontario Ottawa is the capital city of Canada. It is located in the southern Ontario, southern portion of the province of Ontario, at the confluence of the Ottawa River and the Rideau River. Ottawa borders Gatineau, Gatineau, Quebec, and forms the cor ...

. ;Gap-filler and semi-mobile radar stations: On 18 January 1952, ADC proposed the construction of small, unmanned stations with gap filler radars. The USAF Directorate of Plans (War Plans Division) "prepared the proposal … to add 29 mobile and 135 low-altitude stations to ADC's radar system" for completion by the end of 1955. The first phase began with three 1953 stations at Walker M-90, Ellsworth M-97, and Houma M-126 (Z-126); and was completed with 1957 stations at Almaden M-96 (Z-96), Mount Hebo M-100, Jacksonville M-114 (Z-114), and Cherry Point M-116.
The "second-phase mobile radar program" was requested by the ADC commander in October 1952 and was completed from 1954 starting with

SM-172 through 1962 with Hastings SM-133 (Z-133). The ''Planning Guide for the Third Phase Augmentation Radar Program was issued 5 April 1954, and the 3rd phase was for 29 stations, many for coverage along the U.S.-Mexican border and the Gulf of Mexico (the Air Force Council had agreed with ADC's request for the third phase on 28 October 1953.) The "resulting 104 stations were all to be operational by 1956", and a mock 1956 attack blinded ground defense radars. The third phase of 29 stations was deployed beginning with 5 1957 stations and ended with the 1960 Sundance TM-201 (Z-201). Gap-filler annexes of Mather P-58 (P-58A at

Modesto Modesto ( ; ) is the county seat and largest city of Stanislaus County, California, United States. With a population of 218,069 according to 2022 U.S. Census Bureau estimates, it is the 19th-most populous city in California. Modesto is locate ...

& P-58B at Oroville) were some of the Permanent System stations planned, but never built. Texas Towers were approved on 11 January 1954, and despite 11 Permanent System radar stations closing in 1957 ( N-28 Pinetree station and the M-87, M-101, M-104, M-105, M-106, M-109, M-122, M-128, M-131, & SM-137 stations), at "the end of 1957, ADC operated 182 radar stations…32 had been added during the last half of the year as low-altitude, unmanned gap-filler radars. The total consisted of 47 gap-filler stations, 75 Permanent System radars, 39 semimobile radars, 19 Pinetree stations,…1 Lashup era radar and asingle Texas Tower". ;Relocated stations: When radar stations began converting to SAGE, 8 Permanent stations that closed from 1959-1964 had their squadrons relocated to stations with "RP" designations, including the radar squadrons from the last 2 remaining "LP" stations: ( Elkhorn/Williams Bay LP-31 and Blue Knob/Claysburg LP-63). All but 1 of the relocating squadrons went to new sites (the 770th moved to a 1955 Army radar station designated USAF RP-54 in 1961), and 5 of the units co-located with

Project Nike Project Nike (Greek: Nike (mythology), Νίκη, "Victory") was a United States Army, U.S. Army project proposed in May 1945 by Bell Laboratories, to develop a line-of-sight (missile), line-of-sight anti-aircraft missile system. The project del ...

Missile Master units. A 1959-1961 USAF radar squadron was at the Fort Heath radar station of the joint-use site system (JUSS).

Replacement

Groundbreaking for the SAGE System facilities began in 1957, Ground Observer Corps operations ended in 1958,https://news.google.com/newspapers?id=VukVAAAAIBAJ&sjid=dBAEAAAAIBAJ&pg=1611,526065&dq=filter-center&hl=en and most Permanent System radar stations were modified to have an AN/FST-2 computer to provide the automated environment (

cf. The abbreviation cf. (short for either Latin or , both meaning 'compare') is generally used in writing to refer the reader to other material to make a comparison with the topic being discussed. However some sources offer differing or even contr ...

Mather AFB which relayed data through Mill Valley AFS). On "June 26, 1958,…the New York sector became operational" with the SAGE Direction Center at McGuire AFB (DC-01), and in 1959, ADC's Air Divisions and the AC&W Squadrons were redesignated, e.g., the

27th Air Division The 27th Air Division was a United States Air Force numbered air division and the geographic Air Defense Command region controlled by the 27th AD. Its last assignment was with Air Defense Command (ADC)'s Tenth Air Force, at Luke Air Force Bas ...

was renamed between 1 February 1959, and 1 April 1966, as the Los Angeles Air Defense Sector (LAADS); and the 609th AC&W Sq became the " 614th Radar Squadron (SAGE)" on 1 September 1959. Permanent System stations not included in the SAGE network were phased out beginning with 9 in 1957; then the first closure for SAGE of a 1951 station (Roslyn P-3) was in 1958. The radar stations were redesignated with NORAD identification numbers Z-2, etc. on 31 July 1963. The SAGE centers were subsequently replaced with the full operational capability of 7 Joint Surveillance System centers on 23 December 1980, and remaining radar stations of the permanent network include the former 1951 P-37,

P-38 The Lockheed P-38 Lightning is an American single-seat, twin piston-engined fighter aircraft that was used during World War II. Developed for the United States Army Air Corps (USAAC) by the Lockheed Corporation, the P-38 incorporated a distinc ...

, and RP-39 which became FAA Ground Equipment Facility radar stations of the Joint Surveillance System.

References

{{Reflist , refs= {{Cite report , last1=Del Papa , first1=Dr. E. Michael , last2=Warner , first2=Mary P. , date=October 1987 , title=A Historical Chronology of the Electronic Systems Division 1947-1986 , url=http://apps.dtic.mil/dtic/tr/fulltext/u2/a201708.pdf , archive-url=https://web.archive.org/web/20131224105532/http://www.dtic.mil/dtic/tr/fulltext/u2/a201708.pdf , url-status=live , archive-date=24 December 2013 , number=ESD-TR-88-276 (AD-A201 708) , accessdate=2012-07-19 , quote=''so-called Semi-Automatic Direction Center System, later known as…Semi-Automatic Ground Environment System, in essence, the Lincoln Transition System.'' {{cite AV media , others=Morton, Colonel John (narrator) , title=In Your Defense , url=https://www.youtube.com/watch?v=06drBN8nlWg , format=digitized movie , publisher=Western Electric , accessdate=2012-04-03 compiled by {{Cite book , last1=Johnson , first1=Mildred W , date=31 December 1980 , orig-year=February 1973 original by Cornett, Lloyd H. Jr , title=A Handbook of Aerospace Defense Organization 1946 - 1980 , url=http://www.usafpatches.com/pubs/handbookofadcorg.pdf , publisher=Office of History, Aerospace Defense Center , location= Peterson Air Force Base , page={{Verify source, date=April 2012 , accessdate=2012-03-26 {{Cite report , last=Schaffel , first=Kenneth , year=1991 , title=Emerging Shield: The Air Force and the Evolution of Continental Air Defense 1945-1960 , url=https://archive.org/details/TheEmergingShield , format=45MB

pdf Portable document format (PDF), standardized as ISO 32000, is a file format developed by Adobe Inc., Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, computer hardware, ...

, work=General Histories , publisher= Office of Air Force History , isbn=0-912799-60-9 , accessdate=2011-09-26 , url-access=registration {{Cite book , chapter=Chapter 3: Planning for Air Defense in the Postwar Era , title=Emerging Shield , pages=47-81 (pdf pp. 62-96) {{Cite book , title=History of Strategic and Ballistic Missile Defense, 1945-1955: Volume I , url=http://www.history.army.mil/html/books/bmd/BMDV1.pdf , archive-url=https://archive.today/20240514145936/https://www.history.army.mil/html/books/bmd/BMDV1.pdf , url-status=dead , archive-date=14 May 2024 , quote=''Stations were undermanned, personnel lacked training, and repair and maintenance were difficult. This stop-gap system later would be replaced by a 75-station, permanent net authorized by Congress and approved by the President in 1949 … To be closer to ConAC, ARAACOM moved to Mitchel AFB, New York on 1 November 1950.'' {{Cite book , chapter=Chapter II: American Strategy for Air and Ballistic Missile Defense , title=History of Strategic Air and Ballistic Missile Defense, 1945–1955: Volume I , pages=37–68 {{Cite report , last1=Winkler , first1=David F , last2=Webster , first2=Julie L , date=June 1997 , title=Searching the Skies: The Legacy of the United States Cold War Defense Radar Program , url=http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA331231 , archive-url=https://web.archive.org/web/20121201202922/http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA331231 , url-status=dead , archive-date=1 December 2012 , publisher=U.S. Army Construction Engineering Research Laboratories , lccn=97020912 , accessdate=2012-03-26 , quote=''"BUIC II radar sites would be capable of incorporating data feeds from other radar sectors directly onto their radar screens. '' 20th-century history of the United States Air Force

Planning

Description

Manual Air Defense Control Centers

Radar stations

Replacement

See also

References